Aphid is a sucking insect from the order of Hemiptera green, brown, black, 2 mm. Forms colonies mainly on the tops of the shoots. There are colonies of wingless and winged individuals. When the plant is located outdoors (on the ground) in the summer, ants are often indicators of damage, which feed on the sweet secretion of aphids, droplets of sticky honeydew are also observed on the leaves.
Measures to combat aphids. Single or double treatment with Actara (spraying at a concentration of 4 g / 5 l and watering at a concentration of 1 g / 10 l), Akarin, Agravertin or Iskra-bio (spraying 5-8 ml / l), or another insecticide according to the instructions. During processing, insects may not die immediately, but after a few hours. All plants in the house should be treated, as aphids move easily.
Weevils.
Weevils are shiny small beetles, the body shape is elongated to rounded. A distinctive feature is the presence of a rostrum (an elongated part of the head). They feed on leaves, flowers, roots, sometimes being inside plant tissues. Often, adult insects feed on the aerial parts of plants, their larvae feed on roots. On indoor plants, the presence of weevil can be identified by round or semicircular holes in the leaves. You can not see the weevil right away, because it is nocturnal. The most effective will be systemic preparations of intestinal action Measures to combat the weevil. Manual collection of adult insects, spraying with Aktara (4 g/5 l), spilling the soil with Aktara (1 g/10 l), 4-fold treatment every 7-10 days.
The spider mite belongs to arachnid arthropods; it feeds on cell sap through leaf bites. Is a common pest indoor plants. Signs of damage: on the underside of the leaf (sometimes on the top) there are small, about 0.5 mm, light grains (as if sprinkled with flour), with mass destruction visible web. The leaf at the bite is discolored, covered with small yellow spots. Subsequently, with a strong defeat, the leaf falls off. The mite easily spreads through the air, is present always and everywhere, but affects only weakened plants. Strong plants that are kept in optimal conditions are able to resist the mite. Risk factors include too dry air, overheating of a plant or a clod of earth in the sun, drying out of the soil, dehydration (sometimes roots rot and die due to excessive watering), improper feeding, often an overdose of nitrogen fertilizers.
Methods of dealing with spider mites. In order to prevent the plant, it is useful to spray it often with cold (namely cold) water, especially the underside of the leaf. For emergency assistance, it is necessary to wash the plant in the shower and treat with acaricides. IN room conditions it is better to use Vertimek, Fitoverm. However, these drugs do not act on all stages of the tick - at least three treatments are required at + 200C after 10 days, or at + 300C after 3-4 days. Treatment with Akarin, Agravertin, Neoron will also help (4-fold treatments with an interval of 7-10 days). However, if the rules for caring for the plant are not followed, chemical treatments will only help for a while. To completely get rid of the tick, it is necessary to provide the plant with optimal conditions. Then strong cell walls are formed, which the tick is not able to damage. Prophylactic irradiation of medical equipment is effective. ultraviolet lamp for 1.5-2 minutes weekly (to prevent the development of a new generation of individuals from eggs, which occurs exactly within 7 days). Methods of dealing with gall nematodes. It is necessary to try to remove badly damaged areas of the roots. Thermally treat the root system and soil by immersion in a large volume of water with a temperature of +500C. Of the chemicals, Fitoverm or Agravertin are recommended when a dry powder is applied to the soil, but there are no drugs in retail sale in this form. Ecogel proved to be effective against nematodes, which was initially considered only as an anti-stress drug. Chitosan, which is part of the Ecogel, strengthens the cell walls so much that the nutrition and spread of the nematode in the tissues of the plant becomes impossible. It should be borne in mind that in some plants the presence of nodules on the roots is the norm, they should not be confused with galls. In members of the legume family, nitrogen-fixing bacteria live in such nodules. The water-oil emulsion is based on the effect of oil blocking the spiracles of insects. To give greater covering power, the oil is mixed with soap solutions. A glass of water is taken a little dishwashing detergent or soap and 2-3 tbsp. tablespoons of machine (can be sunflower) oil, all this is shaken until an emulsion is formed and applied with a cotton swab or brush to all surfaces of the plant, while it is imperative to protect the soil from emulsion drops. The plant is left treated for several hours, then thoroughly washed in the shower. The tolerance of the leaves to such exposure should be checked.
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Hibiscus: care
Who doesn't want to have a flowering tree in their house? Especially if, in terms of whimsicality, it is inferior to many of its brethren! Chinese hibiscus is called a rose for a reason, the flowers of some species really resemble a blossoming rose bud. How to provide the conditions in which the plant will bloom?
Family: Malvaceae. Flowering: regularly. Cultivation: simple.
Hibiscus - Chinese rose (species, photo)
The first information about the plant refers to Ancient Greece. By the way, the Mediterranean climate is a favorable environment for Chinese roses! Its habitat covers the countries of the tropical and subtropical climate. For example, on the streets of Vietnam or Thailand, the rose feels great! The flower belongs to the mallow family, and its genus includes not only shrubs, but trees and even herbs, in total there are up to 500 different species.
In places of original growth, local aboriginal women wove its flowers into their hair, perhaps that is why the plant was called the “flower of beautiful women”! Initially, Chinese hibiscus was a tree up to 5 meters high, but for indoor cultivation breeders have bred more miniature varieties. And, although the rose allows you to admire its flowers for only one day, the flowering period can last for months! And terry flowers will delight you for up to three days.
Do you know?
In Malaysia, the flower received the title of national. Its five-petal variety is a symbol of the five commandments of Islam!
By the way, the view is not limited to the Chinese representative. Syrian hibiscus, native to Asia Minor, is a shrub suitable for outdoor cultivation. However, only for the southern strip of Russia. Indeed, in the conditions of a short summer, he simply does not have time to bloom! Its flowers are often confused with mallow.
There is another species that is sometimes called a weed, this is the ternary hibiscus. A flower up to 80 cm high has chosen the African continent, and grows by itself in pastures and wastelands. Perhaps that's why he got such an offensive nickname!
hibiscus syriacus and trifoliate
Hibiscus dissected-petal - this beautiful view received the name "princess earrings". It is shaped like a bell with curved petals resembling wings. exotic bird! It comes from Brazil, grows in the coastal strip, or tropical forests, suitable for home floriculture.
hibiscus dissected
Do you know?
The plant is edible! The flowers are used in tea, the leaves are added to salads, the seeds are used for confectionery purposes, and the ripened fruits are highly valued for making jams, compotes and even soups.
By the way, the famous hibiscus tea has nothing to do with the usual indoor rosan! The raw materials for it are the cups of Sudanese hibiscus flowers, which increase in size after flowering. Unlike its relatives, this species is distributed mainly in the Arab countries, especially in Egypt and Sudan due to climatic preferences.
sudanese rose
Care rules
At home, hibiscus is not picky. Sometimes you can observe gorgeous flowering plants in completely unsuitable conditions! And yet, if you want to achieve a beautiful crown and long flowering, you need to make a little effort! Hibiscus care and cultivation.
Temperature and lighting
The only whim of a flower is that it needs light! In summer it should be diffused sunlight, with shading from direct rays. In winter, when the sun is scarce, it is necessary to provide it with artificial lighting in order to extend daylight hours to 10-12 hours. How to create backlight for flowers?
Hibiscus Chinese is able to bloom even in winter, if the room is warm and light. Feel free to take it out in the summer! The flower is not afraid of temperature changes. But when it drops to 12 degrees, it is advisable to return it to the room, in such conditions the roots stop absorbing moisture.
Watering and humidity
In summer, wide leaves actively evaporate moisture, the higher the temperature, the more active watering should be. However, don't overdo it! It is better to water it less often, but more abundantly than to supply water often and in small doses!
In addition, the flower itself signals the need for watering by lowering the leaves. It is preferable to water in the morning, during the day the roots actively consume water. With a decrease in temperature, watering is reduced. 8 questions about watering indoor plants.
Be sure to spray the Chinese rose, it needs moist air no matter the season! Sometimes arrange a plant warm shower, after covering the pot with a bag. Hibiscus, the care of which is not difficult even for a beginner grower, is a very grateful plant. If the minimum conditions are met, it will definitely bloom! No wonder it is called the “flower of love”. During abundant flowering it is desirable to minimize spraying. After all, moisture that gets on the petals of flowers accelerates the process of their withering.
Fertilizers and top dressings
Experienced flower growers have noticed that an excess of phosphorus does not have the best effect on the quality of flowering! Conventional fertilizers for flowering crops contain minerals in the following proportion ≈15-21-25 (nitrogen, phosphorus, potassium). A more successful dosage would be ≈ 10-4-12 (nitrogen, phosphorus, potassium). Therefore, carefully study the composition of the fertilizer! How to choose mineral fertilizer.
To prevent chlorosis, Chinese hibiscus can sometimes be fed with magnesium on a leaf (leaf method). The plant responds well to organic fertilizers- mullein and ash. It is especially important to fertilize a rose in the spring and summer, during flowering and growing new leaves. By the way, before you "feed" the roots with fertilizer, you must first moisten them with water for irrigation! How to use organic for flowers.
Foliar top dressing will be useful - spraying with stimulating drugs, organic, or mineral fertilizers in a reduced concentration (10 times lower than with root top dressing). In winter, if the leaves continue to grow, you can fertilize the rosan once a month. With a pronounced dormant period, fertilizers are not used!
Hibiscus pruning!
Hibiscus care involves regular pruning, it is needed to renew the crown and is a guarantee of flowering. If your pet already blooms regularly, and also has a crown desired shape He doesn't need a haircut. Although they say that this flower can be cut all year round, this is not true! In conditions of short daylight hours, it will be difficult for him to grow new leaves, and the old ones will turn yellow. Therefore, it is more reliable to cut the crown in the second half of March-April, when the sun is already active. Then it is guaranteed to bloom in June-July. Do not be afraid of "cardinal haircuts", new leaves will grow quickly!
It is better to prune three days after watering. Keep in mind that the location of the leaf gives the direction of the escape! So, leaving the last leaf growing down, you will get a new branch that will repeat its direction. As shown in the photo, when cutting, step back from the sheet by about 5 mm.
Reproduction and transplant
The cuttings obtained after pruning are easily rooted in water, after which they can be planted in the ground. Some varieties are successfully propagated by seeds. It is desirable to transplant Chinese hibiscus by transshipment, as its roots are fragile and thin! A transplant is required only if the rosette, in your opinion, is cramped in a pot. In a container that is too large, the tree gives new leaves, but does not bloom. How to choose a flower pot.
The soil for the plant must be nutritious and moisture-intensive, for this garden soil is mixed with humus, peat and sand in equal proportions. The flower must be provided with good drainage and air access to the roots. Don't forget to loosen the ground sometimes! The first time after transplanting, it is recommended to water the rose from the pan to stimulate root growth. What kind of soil is right for your flower.
Growing problems?
Hibiscus, the care of which does not require much effort, can sometimes still be capricious! What are the most common ailments associated with?
- If the hibiscus turns yellow and the leaves fall ...
In winter, the cause of leaf fall may be a lack of sun. For deciduous plants this is the norm! To keep up the strength room rose, you can carry out foliar feeding with a solution of magnesium sulfate. However, if there is massive yellowing, it is worth checking the rose for pests. Eg, spider mite! Especially often it attacks weakened plants. Its presence is betrayed by a cobweb between the leaves, and sometimes the tick itself can be seen on the back of the leaf. In any case, bathe the rose in the shower more often as a preventive measure!
Another reason could be a change temperature regime. In the cool, the roots stop drinking water, so the plant can be easily flooded. Be careful!
- If the hibiscus has faded leaves ...
In this case, the spider mite could “try”! But, perhaps, a plaque from water, or dust, simply accumulated on the leaves. Keep in mind that the older the leaf, the less bright its color becomes. Mostly young leaves are juicy! Shaping pruning, enough light and periodic warm showers can save the situation.
- If the hibiscus has deformed leaves ...
This phenomenon is often observed after transplantation if there has been damage to the roots! The rose will recover quickly if provided with good lighting, regular watering and top dressing, including foliar. It is worth noting that slight deformation leaves, namely corrugation - a natural feature of Chinese hibiscus!
Also, the reason may be a sharp change in conditions of detention: cooling, watering or spraying with cool water, excess fertilizer. Delicate leaves noticeably react to any changes, especially with regards to the temperature regime. Even a short-term drop in temperature could cause deformation of young foliage! If conditions stabilize, new leaves should grow evenly.
- If the tips of the leaves of the hibiscus dry ...
Usually this situation occurs in winter, when the apartment is dry from batteries and there is not enough light. Winter is a hard time for a flower! If possible, you need to provide it with artificial lighting, spray it often, wash it in the shower and water it with great care. During this period, do not rush to fertilize hibiscus, it is better to start top dressing in the spring. If the room is cool, or the pot is on a cool windowsill, the roots may stop absorbing water altogether. In this case, watering is reduced to a minimum so as not to flood the plant.
This plant needs at least 6 hours of sunlight to flower! Put it closer to the window, in the summer you can safely take it out to the balcony or veranda. Fresh air does wonders for the plant! But, do not forget to shade the tree from direct midday rays.
- If the hibiscus is dropping buds...
According to one version, he may not have enough light, or food. An overabundance of minerals in the soil is also possible! Think about whether you have overfed your flower? Feeding should be carried out no more than once every 10 days, strictly observing the dosage. Also, the reason could be a change in location, or temperature. In general, when the rose has bloomed, it is better not to change the conditions of detention.
- Sticky sap on hibiscus leaves...
droplets of sticky substance inside leaf is normal for a Chinese rose! It may be due to temperature changes, or overheating. And yet, it is not superfluous to check the plant for pests (aphids, scale insects).
It is important to know:
If you have any questions, be sure to ask them in the comments or on the forum. ✿ If you liked the article, share it on social networks.
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Hibiscus indoor. Care
The very first indoor “flower” that I grew with my own hands is Chinese hibiscus, or, as we called this plant, Chinese rose. I remember very well the day he appeared in our house. I am 15 years old. In the lobby of the polyclinic, a huge and obviously once beautiful bush. Constantly looking around, I 
I break off a branch and hide it in my bag.
Over the years, the Chinese rose has experienced many events with me. And just recently I celebrated her 25th birthday.
Chinese hibiscus, or Chinese rose (Hibiscus rosa-sinensis) is a plant of the Malvaceae family. The birthplace of this incredibly beautifully flowering shrub is Southeast Asia and Polynesia. In nature, it reaches a height of 4 m or more. Thanks to the work of breeders, today there are about 250 varieties of Chinese roses of a wide variety of colors, and 25 years ago we knew only a red-flowered terry form.
Those who decide to have a hibiscus in their home should remember that this is a sprawling, fast-growing shrub that will need a large pot, and, therefore, a fairly spacious place in the house. True, now compact slow-growing varieties have appeared on sale.
Hibiscus is easy to grow from non-lignified green shoots remaining after the annual spring pruning. Cuttings with 2-3 leaves are cut from them. Large leaf blades are shortened by half to reduce moisture evaporation. Sometimes, in the process of rooting, the leaves on the cutting fall off, but the cutting itself remains alive. As soon as roots develop on it, new leaves grow from sleeping buds.
Hibiscus can be rooted in water. When small white growths (callus) appear on the lower end of the cutting, it is planted in a small pot in an earthen mixture, watered abundantly and placed in a greenhouse. She can be replaced plastic bag or transparent plastic bottle necessarily with ventilation holes. With the advent of young leaves, the plant can be removed from the greenhouse and put on permanent place.
Rooted cuttings bloom in the year of planting. Already 4-month-old young shoots "throw out" bud after bud from the apical point of growth. It's funny to see how tiny buds appear on a thin stem. They gradually increase, and within a few days a huge double flower blooms, up to 10 cm in diameter!
It lasts exactly a day, and then falls off, giving way to the next one. Continuous flowering occurs until late autumn, and on the southern windows - all year round.
As soon as the hibiscus begins to prepare for flowering, it should be given more attention. The fact is that buds and flowers are a great delicacy for peach aphids. If you find uninvited guests, then immediately treat the plant with the Fitoverm insecticide or any other drug that kills the pest. If there are too many aphids, it is better to remove the emerging buds until the plant is completely healed.
Hibiscus needs to be shaped. In the spring, in mid-March-April, long shoots are shortened to stimulate branching. If the plant has only one shoot, it is cut off at an arbitrarily chosen height. If a bush has formed, then you need to follow certain pruning rules recommended by experts. Each shoot is cut 1/3 above the leaf facing outward. I did a little experiment. Part of the shoots was cut according to the recommendation, and part contrary to it, that is, above the inner bud. Those branches that were cut according to the rules gave several side shoots. And the “wrong” ones grew only one young shoot from the upper bud.
In the spring, simultaneously with pruning, the hibiscus is transplanted or transferred to a fresh substrate; young plants annually, adults, start 7-10 years old - as needed. In large tub specimens, the top layer of the earth should be changed annually.
Hibiscus are big "gluttons", so I add a little rotted mullein to a fresh substrate.
Earlier, when I was just starting to do indoor floriculture, I collected rotted leaves in the park and mixed it into the earthen mixture during transplantation. Feed hibiscus every 2 weeks with fertilizer for flowering crops.
In the summer it is better to take them out on open air. Watering with soft rainwater, abundance sunlight, fresh air harden the plant before a long and difficult wintering. The minimum temperature that Chinese hibiscus can withstand is plus 10-12″C. A further decrease in temperature can lead to hypothermia of the root system and death of the plant.
In the autumn-winter period, the flowering of hibiscus weakens or stops altogether. Half-opened buds fall off, and new ones do not form. There is a period of relative calm. At this time, the plant is fertilized no more than once a month. With batteries included central heating there is another danger - the invasion of the spider mite. This pest should also be disposed of with the help of appropriate preparations. A few years ago my hibiscus got sick. What happened, I still don't know. The leaves began to fly around, the shoots stopped growing, the growth points dried up. Wait for death. I didn’t become a plant, I took it out of the pot, examined the roots. They were knotted and very densely interlaced, I did not find anything else alarming. Slightly "stirring up" the root system, cut it off a little with scissors and shortened the shoots. I planted a bush in another pot, completely changing the substrate. Now all that was left was to wait. For about a year, the hibiscus showed no signs of life. He didn't die, but he didn't grow either. No fertilizers and stimulants helped. Quite desperate, I began to water him with urea diluted in water. Slowly, very slowly, the plant began to come to life. For 8 months I tried to help him, and when my hands dropped, my hibiscus suddenly “woke up”: young leaves began to appear, shoots grew. Every day he became more and more like himself. He met his 25th anniversary, covered with new shiny dense foliage.
Chinese hibiscus is propagated not only by cuttings, but also by seeds. However, of all the varietal seeds found on sale, I managed to grow only hibiscus ‘Tsar Bell’. All 5 seeds sprouted together after 3 days, and after 4 months the seedlings reached 50-70 cm in height and began to prepare for flowering. A huge (15 cm in diameter!) flower opened on one of them. Surprising vitality was shown by seedlings, for lack of space left in small pots. Sometimes the substrate in them completely dried up, the leaves hung down and it seemed that the plants could not be saved. But as soon as the pots were immersed in the ox, the turgor was completely restored after a few hours. In autumn, due to insufficient lighting, the seedlings began to lose leaves, then the shoots began to die. When about 10 cm remained to the base of the stems, the dying off stopped. In the spring, the plants began to grow. After the earth warmed up, I planted all 5 seedlings in the ground. However, despite the fact that the inscription “Winter-hardy!” was emblazoned on the colorful seed bag, the plants felt open ground uncomfortable, shoot growth stopped. Until autumn, only 3 seedlings “reached out”, and not one survived the winter.
Thanks to communication with foreign breeders and the arrival of new, hitherto unknown varieties on our flower market, we now know much more about hibiscus than before. There are varieties whose flower size reaches 25 cm in diameter! Now no one will be surprised by the old variety with red double flowers, but it is dear to me, like an old and reliable friend.
On a note:
Varieties of gladioli - VARIETIES OF CHAMPIONS OF GLADIOLUS
Diseases of indoor plants with sticky leaves immediately give out their cause and pathogen.
Causes of sticky plaque
A sticky leaf in any plant means that organic secretions with a large amount of carbohydrates are deposited on its surface.
In a healthy plant, this is possible only if something that sticks to the outer integument of the leaf has got on the leaf blade from the outside. This happens rarely. And if all the leaves of a plant are suddenly covered with something sticky, these are signs of a pathology that develops so quickly that soon not only a few leaves and the whole plant, but also the nearest space around, are covered with a sticky mass. This indicates the presence of a constant process of violation of the integrity of the leaf blade.
Possible consequences
This phenomenon has causes and consequences. The reasons are simple - microorganisms are planted on the plant that damage the leaves. As a result, juice flows from the leaf wound all the time.
Reaching a certain number, the pest forms a sticky cover on the leaves. Since he drinks juice, his secretions are not only thin, but also sticky. As a result, the leaf is covered with a continuous layer of a mixture of its own juice with the secretions of the organisms that eat it.
Such a process may have the following consequences.
- 1. The plant loses water and nutrients.
- 2. Fungi, bacteria, viruses can settle on permanent damage, which can cause a new disease.
- 3. The sticky cover clogs the stomata, making it difficult to breathe and evaporate water.
- 4. Since the plant is not provided with a sufficient amount of oxygen and carbon dioxide, the formation of organic matter in the process of photosynthesis becomes unproductive. This leads to the loss of the leaf and the gradual withering of the entire plant.
- 5. Stomata closed with a sticky substance stop evaporating water. As a result, the movement of water from the root hairs to the leaves slows down. For this reason, the supply of minerals to the ground organs of the plant also slows down. This is the reason for the deficiency of minerals. The intensity of bio and photosynthesis decreases. As a result, the plant ceases to bloom and bear fruit, gradually dying.
Thus, a sticky coating on the leaves of a plant is a signal of trouble. Who is responsible for these troubles?
Organisms that damage the leaf blade
It is difficult to identify a pest that destroys a plant. These are mainly insects or mites, that is, multicellular organisms. However, they are so small that it is difficult to see them. In addition, only a specialist can determine the type.
Nevertheless, it is necessary to know the enemies of plants. Here is a sample list of them.
- 1. Spider mites are the most common houseplant pests. They belong to the arachnids. Their presence is usually detected by indirect signs. Leaf stickiness is the first sign. Then barely noticeable cobwebs appear. If the plant is in bloom, the web concentrates on the flowers. Chrysanthemums, citrus fruits, and roses suffer the most from spider mites.
- 2. Scale insects, or false scale insects, are small insects from the Hemiptera family. They got their name because they look like they are covered from above with a dense protective shell, similar to a shield. Compared to a tick, they are quite large - they can be seen with the naked eye. They lead a sedentary lifestyle. If you try to remove them from the plant, you can feel resistance. It creates a feeling of adhesion of the shield to the surface of the sheet. They usually concentrate near the veins or on a young shoot.
- 3. Aphids for houseplants are not as popular as the previous ones. The reason is simple - these insects are larger, so people notice them faster and take action. However, they are colored to match the color of their food supply, which reduces the likelihood of their early detection. Infection with these insects occurs quickly. This is due to their ability to fly. If previous pests migrate through the soil, then these can fly to new plants.
- 4. Mealybugs are representatives of the same family as scale insects. These worms are not worms at all. In size and lifestyle, they are more like aphids. A person who does not understand the biology of invertebrates usually does not see the difference between aphids and a mealybug. However, there are some indirect signs. The accumulation of these small white insects creates the effect white plaque, as if the plant was sprinkled with flour.
- 5. Whiteflies are small white butterflies. They usually concentrate on the underside of the leaf, since the cover is less solid there.
These butterflies lay their eggs where they feed. Translucent larvae emerge from the eggs, bite into the leaves, move along their surface, leaving a layer of sticky sweet coating. If the concentration of larvae is high, and the leaves are not processed, then the plaque turns from green to black. This is due to the fact that fungi begin to multiply in a sweet environment.
How to deal with adversity?
If you find white dots, brown shields, cobwebs, sticky plaque on the plant, then you can not look for the culprits, because the control measures are the same. They boil down to the following:
- Detected pests can be removed. Wash the plant with the solution laundry soap(72%). You can use special green soap.
In a soapy state, the plant can remain no longer than 24 hours. After that, the soap coating must be washed off, since the soap prevents gas exchange between the plant and the atmosphere.
Repeat the procedure after 3 days.
- In some cases, soap procedures do not help. Then you have to turn to special preparations. Fitoverm belongs to such means. According to the instructions, it is used to treat indoor plants if they are affected by aphids, mites and thrips.
Using Phytoferm is simple. It is necessary to dissolve the contents of the ampoule in water. Attention should be paid to the toxicity of the drug to humans, so the treatment should be carried out with all precautions and outside the living quarters, as there will be an unpleasant odor.
7 days after the first treatment, the entire procedure must be repeated. This is due to the fact that most pests live in the soil, and this drug does not damage them, so the next generation appears.
After about 30 days, you will understand whether Fitoverm helped or not. If not, then it's time to take more drastic action.
- Preparation "Doctor" (thiamethoxam) in the form of briquettes. Distinctive feature This means is the destruction of pests in the soil. To do this, briquettes are introduced into the soil. There they gradually dissolve, killing larvae and adults - aphids, scale insects, scale insects, thrips, whiteflies.
- The entire series of preparations "Commander" has universal properties. They can be sprayed with crops growing in the open field, in pots on the windowsill. These are water-soluble crystals that are effective against aphids, whiteflies, thrips. The concentration of the solution must be selected for specific conditions in accordance with the instructions.
- Some people put the pot with the affected flower in a plastic bag and spray dichlorvos inside, then the bag is tightly closed for several hours.
This method can give its results, but dichlorvos is dangerous for people and can burn the plant, it works for a short time, killing only active insects and mites. The larvae remaining in the soil do not die.
There are many means and methods of pest control. The main thing is prevention. Be careful with soil selection.
Foreword
Chinese rose, also known as hibiscus, is quite unpretentious, but it also has its enemies in the form of various pests and diseases that annoy it. Knowing about the causes of damage to any ailments, you can completely prevent the disease of this plant. And if such an attack has befallen a Chinese rose, then you need to know about how to deal with it.
Most of the diseases of the Chinese rose are associated with improper care for it. And in second place in terms of the number of diseases and the frequency of their manifestation are cases of infection with fungi and pathogenic viruses. But, by the way, the defeat of a rose by most of these ailments also depends on the correctness of its cultivation. After all, when a plant does not receive proper care, it becomes weakened and, as a result, more susceptible to infection by fungi and viruses.
Chinese rose
Hibiscus is resistant to the vicissitudes of fate - it is not very dependent on how it is grown. It means that even serious flaws in caring for it cannot cause significant harm to the Chinese rose. However, this plant "forgives" such negligence only if they are allowed in a single amount. A systematic violation of any requirements of agricultural technology will certainly provoke certain troubles and diseases. Hibiscus will begin to feel bad at first (weaken), and then it will wither and get sick.
So, all currently known diseases of the Chinese rose can affect it due to the following care errors:
- placing the plant in a draft, under the wind or direct sunlight;
- excessive watering, resulting in rotting of the roots;
- placement in a dry or hot room;
- contamination and dustiness of the plant, especially its leaves;
- lack of spraying or when they are extremely rare, especially in summer;
- watering with poor quality water (containing a lot of harmful impurities or not settled);
- poor lighting, and sometimes a flower reversal reverse side to the sun;
- "overfeeding" with fertilizers;
- lack of fertilizing with fertilizers and transplants;
- allowing contact with already diseased plants, as a result of which the hibiscus is affected by diseases and pests.
All these violations in care, subject to their systematic impact on the Chinese rose, provoke various diseases in it. If favorable conditions are provided for this plant, or at least it is not injured by a careless attitude, then it grows for quite a long time and always pleases with its flowering every year from April to October, or even longer.
The first signs of a deterioration in health or disease of the Chinese rose in most cases are any changes in the condition of its leaves, as well as some of the other symptoms listed below. In each individual case, the plant may become unhealthy, usually for one of several reasons. The following are the main symptoms and the most likely causes that caused their appearance.
yellowed hibiscus leaves
If the hibiscus has leaves:
- Turned yellow - the plant is infected with pests (spider mites or aphids), its roots turn white, leaf chlorosis, or the air in the room is not humid enough.
- Turned yellow and fall off - stress (occurs when adverse factors occur or a sharp change in conditions of detention), drafts or insufficiently humid air in the room, and in winter also from waterlogging of the roots.
- Fall off - insufficiently humid air in the room, stress, a sharp change in the intensity of lighting or drafts.
- Wither at the tips - the plant lacks phosphorus and nitrogen, and also, most likely, some other nutrients.
- Twisted into a tube - pest damage, most likely aphids.
- They fall along with the flower buds - it is too hot in the room, the plant lacks potassium, or it is affected by a pest (midge gall midge).
- Wither along with the whole plant - the room is too hot or the humidity is below critical levels for the Chinese rose.
What exactly is the cause of the appearance of most of these symptoms must begin to be clarified by identifying possible shortcomings in care. That is, we determine whether the temperature and humidity in the room, the frequency and amount of watering, as well as spraying and fertilizing with fertilizers required for hibiscus. Then, by the method of elimination, we determine the possible, and, most often, real causes. If they are in improper care, then we eliminate the errors. And how to deal with other causes will be discussed later.
The most common hibiscus diseases will be described below. Most of them are manifested in a change in the appearance of the leaves. Let's start with these ailments in order of their prevalence. Leaf diseases in the vast majority of cases are provoked by chlorosis. This is a disease in which the plant disrupts the formation of chlorophyll and reduces the activity of photosynthesis. The main characteristic signs of this disease in hibiscus are yellowing and/or leaf drop. Chlorosis is of two types - non-infectious and infectious.
Non-infectious rose chlorosis
Most often, the Chinese rose is affected by non-infectious chlorosis. The causes of its occurrence lie in malnutrition: insufficient or excessive supply of nitrogen, potassium, iron and magnesium. Moreover, it should be noted that magnesium and potassium are inherently competing elements. That is, an excess of one causes a deficiency of the second. Symptoms of non-infectious chlorosis in Hibiscus are as follows. With a lack of iron, the leaves turn yellow, and then the leaves fall off. If thinning of the branches is observed, the plant does not bloom at the right time, or its flowers have a pale color (not bright enough), then this indicates a potassium deficiency. When a rose lacks magnesium or nitrogen, the leaves become stained: yellow, whitish or lemon-colored.
Infectious chlorosis, as its name implies, affects the hibiscus due to its infection. The causative agents of this are fungal microorganisms, viruses and even pests. The symptoms of infectious chlorosis are as follows: yellowing and subsequent fall of the leaves, as well as general weakness and lack of flowering of the plant. Perhaps the next most common disease is sunburn. Signs of this disease are the appearance of white spots on the leaves, as in the photo. They arise as a result of the partial destruction of chloroform in green tissues under direct sunlight. This usually happens with plants for which the light intensity has changed dramatically - they have been transferred from a less lit place or from a greenhouse to bright sun.
Vascular wilt is the result of infection of hibiscus with fungi of the genus Verticillium or Fusarium. With verticillosis, the leaves of the plant begin to curl from the bottom of the trunk and turn yellow. This process then moves up the stem. In a severely affected rose, only the very top will remain green. If the room is hot, then the leaves wither very quickly, not having time to curl, causing the plant to look like it has been scalded. Fusarium manifests itself in the slow wilting and subsequent death of the leaves without changing their color, that is, they remain green at the same time. The upper leaves may become watery at the edges, and some areas may acquire a pale green or light yellow tint. In both cases, after the defeat of all leaves, the trunk quickly dries up and the plant dies.
Bacterial spotting
Bacterial spotting is a disease, the manifestations of which can be observed not only on the leaves, but also on the shoots. Basically, this ailment in Hibiscus is caused by bacteria of this kind, such as Xanthomonas. This disease most often affects young shoots and leaves. Depending on the specific type of pathogen, the symptoms of the disease may vary slightly. The most characteristic and common picture is when watery yellow small spots first appear on the stems and leaves (seen in the photograph), which gradually turn black. The shape of the spots is most often irregularly angular, and a light green or yellow border is visible along their contour. The spots gradually increase in size and then merge. As a result, the entire sheet turns black. So the disease progresses throughout the plant and eventually it dies.
Another variant of spotting caused by bacteria is bacterial burn. Its causative agent is other bacteria belonging to the genus Pseudomonas. Most often, a bacterial burn begins with young shoots, leaves and flowers. Its symptoms are as follows. It is not spots that form on the plant, but immediately rather extensive shapeless blackening areas (as in the photo), which soon dry out. Outwardly, such areas on the sheet look as if it was burnt in this place. Progression bacterial burn first causes the death of individual parts of the plant, and then its death. At favorable conditions this disease develops very quickly.
When affected by brown rot, the hibiscus stems turn brown and thin at the very base. The rose is greatly weakened and may die. Most often, this disease affects young seedlings and plants.
Most of the problems that have arisen with hibiscus are solved by normalizing the conditions of its maintenance and eliminating errors in care. Since the purpose of this article is not to consider exactly how to care for the Chinese rose, all these points will be omitted. Let us dwell only on the elimination of a number of specific omissions in care, indicated above in the chapter on the main symptoms of plant deterioration. In case of insufficient humidity in the room, the plant should be sprayed more often - not once, but several times a day. At the same time, waterlogging of the soil should not be allowed - so that after such a “shower” the water is already standing in a pot. If the Hibiscus is hot, then in the room with it, you should try to lower the temperature, and you should also shade it and spray it.
Chinese Rose Fertilizers
When a plant lacks some nutrients, then, of course, it is necessary to feed it with appropriate preparations, which include exactly the missing elements. If the roots become waterlogged in winter, then watering should be temporarily reduced in quantity and volume, and the plant itself should be sprayed instead, making sure, again, that less water gets into the soil and it does not turn into a liquid slurry. What to do in case of drafts is clear and so - it is necessary to eliminate the cause of their occurrence or move the Chinese rose to another, more peaceful place.
Now about the treatment of diseases. Non-infectious chlorosis can not only be defeated, but also prevented by regular feeding of Hibiscus with fertilizers. If, nevertheless, this misfortune happened, the emphasis should be placed precisely on those dressings that contain the missing elements. It should also be noted that the symptoms of iron deficiency (yellowing of the leaves) appear against the background of a lack of nitrogen and an increased content of chlorine and calcium in the water used for irrigation. Therefore, before watering, the water must be defended, and then a microfertilizer such as iron chelate should be added to it. The latter should be done if there is indeed an iron deficiency. And you need to monitor the sufficiency of the amount of fertilizing containing nitrogen.
Infectious chlorosis is best prevented. To do this, contact of the Chinese rose with diseased plants should not be allowed, it must be timely transplanted and fertilized, and it must also be regularly cleaned of dust and dirt. The latter is best done by washing the hibiscus in the shower. At the same time, the soil in the pot must be covered with cellophane. And yet, all new plants brought home must necessarily undergo a temporary quarantine procedure. That is, for several weeks they must be placed separately and away from existing flowers. In case of hibiscus disease, use appropriate preparations (designed to combat identified diseases and pests) to treat it.
To prevent sunburn, Chinese roses grown in greenhouses and grown in a darkened room should be accustomed to changing lighting gradually, taking them out in the sun for an hour and a half a day. Then we gradually increase the duration of the plants' stay in bright light, and only after full adaptation to it do we change their “place of residence”. If, nevertheless, the hibiscus got burned, it's okay. He quickly gets used to the change in lighting, and the leaves that have received burn spots simply fall off, giving way to new normal ones that soon grow.
Zircon for rose processing
Vascular wilt is very difficult to treat and it is not always possible to heal hibiscus from it. Often he quickly dies and at the same time it happens that he did not even have time to fall off the leaves. To fight this disease should be as follows:
- We cut off all the affected (dried) fragments of the plant, while slightly capturing its healthy parts.
- We process the whole rose with special antifungal compounds: Fundazol, Topsin, Dezavid, Alirin-R or others. You can also use the drug Rovral, the solution of which must be poured under the root. There is also a folk remedy - spraying the plant with a solution Trichopolum(for 1 liter of water 2 tablets).
- Additionally, you can stimulate the protective mechanisms of the rose by treating it with drugs. Appin, Zircon, House flower. You just need to make sure before that that the selected composition can be used in combination with the antifungal agent used.
If at the initial stage it was not possible to cure vascular wilt, and the hibiscus continues to hurt and wither, it will have to be destroyed. Bacterial spot is remarkably cured by spraying the plant itself while watering the soil in the pot with a solution. Trichopolum(for 2 liters of water 1 tablet). Also effective are such well-known copper-containing preparations as blue vitriol and Bordeaux mixture. Not only for treatment, but also for prevention can still be used Fundazol, Euparen. To prevent damage by brown rot, hibiscus cuttings and seedlings must be treated with a means Rovral. In addition, seedlings should be planted shallow, and after planting, carefully sprayed with the same preparation.
When a plant is stressed, the first thing to do is try to figure out what caused it. If the reason is the onset of a strong deviation of the conditions of detention from those necessary for hibiscus, then it must be eliminated. The plant is unlikely to adapt to this, especially if the changes that have occurred are in principle unacceptable for its life. Stress can also occur due to the fact that the rose is greatly disturbed, for example, they often change her “place of residence” (they constantly transplant or transfer from one place to another, which usually happens during repairs and relocations) or do not monitor the behavior of children and pets that show excessive curiosity about houseplants.
Signs of Stress in Hibiscus
Such impacts on the plant must also be immediately stopped. In the first case, the hibiscus should, at least for a while, be left alone until it copes with stress (stop transplanting or choose the most suitable for it). appropriate place, from which it will not need to be transferred for a relatively long time). In the second, to forever protect the plant from domestic "robbers", that is, for example, to find a place inaccessible to them.
Stress can also be caused by minor changes in the conditions of detention, when their main parameters are within acceptable values (associated with: transfer from one room to another or from a greenhouse to a permanent habitat; with slight deviations from the previous care), seasonal changes in environment(for example, a decrease in the level and duration of lighting in winter), any damage, transplantation or flowering (also stressful for young and weakened plants). In this case, no drastic measures will have to be taken.
Well, with the stress itself, the Chinese rose, as a rule, is able to cope on its own. In the first two cases, this will happen after the elimination of the causes that provoked it, and in the last - due to adaptation to new conditions. But in order for the plant to successfully and quickly cope with stress, it is necessary for it to provide peace, spray more often and more carefully monitor compliance with the schedule and norms of watering and feeding, as well as the quality of the water and fertilizers used for this.
In addition, hibiscus can be helped to stimulate adaptive processes in it with the help of anti-stress drugs, especially if the stress state does not go away for a long time and the plant is severely weakened. These include: Zircon, Fitosporin, Planriz, Epin-Extra, Planriz, Krezatsin. Such preparations have an immunostimulating and anti-stress effect on plants. It is necessary to choose and use the desired “drug” in accordance with the instructions for it.
The most common pests and their control
Pests start on a plant in two cases: when they are transplanted into infected soil or as a result of contact with already diseased flowers. Hibiscus is most often affected by the following pests.
Aphid. This small insect settles primarily on young leaves and shoots, as well as on the buds of the plant. It multiplies very quickly, creating entire colonies. It is able to completely destroy unopened flowers and young leaves, which at the initial stage of the lesion become sticky and deformed. It is necessary to fight aphids by treating the plant with drugs Akarin, Fitoverm, Biotlin, Intra-Vir, Decis. Also good help Nicotine sulfate And tobacco dust. On early stages and in cases of a single partial defeat of the leaves, it is sufficient to confine the treatment to the usual soapy solution.
Spider mite. You cannot see this pest without a magnifying glass, especially since it settles at the bottom of the leaves. The latter, when struck by a tick, first fade and become covered with small yellow specks, which is clearly visible in the photograph. The pest envelops the underside of the leaves with a dense web, in which it lives. Subsequently, if measures are not taken immediately, extensive dried patches form on the leaves. The fight against a tick includes washing the leaves with soapy water or mineral oil and then treating the plant with preparations. Akarin, Lightning, Vertimek, Fitoverm.
Whiteflies. They usually hide on the underside of the leaves, where you can find their adults and pale yellow larvae (shown in the photo). A characteristic sign of damage to a plant by a whitefly is the appearance of a shiny sticky coating on the upper side of the leaves. These are pest excrements. After some time, sooty fungi develop in them, due to which the surface of the leaves becomes first white and then black. It is these fungi that can cause severe damage to the plant, and not the whiteflies themselves. In addition, this pest is a carrier of various viral infections. The symptoms of whitefly-borne diseases can be very different. This is chlorosis, and the leaves may turn yellow, deform, curl.
It is necessary to fight this pest by treating the plant with a solution of potassium soap or Aktara, Admiral, Biotlin, Bankol, Spark, Appleud, Fufanon, Tanrek preparations.
Worms. Signs of plant damage by them: waxy lumps and powdery coating appear in the axils of the leaves and on the cuttings. white color as in the photo. Methods of struggle: treatment with the same preparations as for the whitefly.
Shields and false shields. Signs of damage: pale brown or brownish rounded scales (tubercles) appear on the stems and leaves of the rose, which can hardly be separated from the plant. These are adults of the pest. With a slight lesion, we clean the scales with a cloth or a toothbrush dipped in a soapy or alcohol solution. A kerosene-soap emulsion also helps well. In case of severe damage, we use one of the above insecticides.
Midge gall midge. Signs of damage: leaves and more unopened buds turn yellow and fall off. It is necessary to inspect the buds and identify all the affected ones. Small eggs of the pest will be visible in them. All these and yellowed buds must be cut off. They must not be allowed to fall to the ground. Then we cultivate the land with one of the above insecticides.
Hibiscus is a popular plant that can give its owner cause for concern. For example, when the tips of the leaves dry on a plant, and it gradually fades. This can happen if your hibiscus variegated is attacked by diseases and pests. In this article we will tell you why hibiscus leaves curl, what to do and how to treat a flower at home.
One of the reasons why the leaves of a houseplant begin to curl is pests. For example, a flower affected by a whitefly (whiteflies are one of the most dangerous pests), has yellow leaves covered with sticky drops over their entire surface. In addition to the whitefly, other hibiscus pests threaten the plant: aphids, gall midges and spider mites.
Aphids are another misfortune familiar to people who are fond of floriculture. Aphids are usually attracted to the fleshy shoots of the plant, so they attack it quickly and drink juices from it. One of the characteristic signs of the appearance of this pest is that the plant twists the leaves, and subsequently sticky droplets quickly appear on the leaves.
To combat aphids, the following methods are used: first they should be removed from the leaf and stem with a cotton pad, and then treated with soapy water or special preparations (Aktara, Iskra).
Gallica
Another reason why the leaf plate twists and falls off is the gall midge, which poses a threat to both the leaves and the root system of the plant. Usually, pest eggs can be found in the buds of a plant - it is there that worms hatch from the eggs, gnaw on the buds, and then fall into the soil, closer to the roots of the plant.
Diseases and their causes
In addition to the invasion of insects, your flowers can also be subject to diseases. Hibiscus diseases, if left to chance, can cause the death of the plant. Rotting roots, leaves starting to dry out - all this clear signs that the hibiscus needs help. It's not about various types rot when the plant has rotted or its roots have dried up, but about diseases that affect the condition of the foliage of the flower. So, let's look at the main leaf diseases and their treatment.
Chlorosis
Chlorosis is nothing more than the loss of leaves of their color. The leaves affected by the disease rapidly lose color and become very pale, even slightly yellowish. The disease is most dangerous because the leaves may not only lose their color, but over time they may begin to fall off. Thus, if you do not take any measures, soon your hibiscus may remain completely naked.
sunburn
Another misfortune that poses a significant danger, but in essence is not a disease, is sunburn. Everything is simple here: sunburn occurs as a result of violation of conditions of detention. Hibiscus, like the vast majority of plants, does not tolerate direct sunlight. Therefore, if you forget about it and place him in a place where he will be under their direct influence, be prepared to accept the consequences in the form of a sunburn.
Also, this misfortune can appear if you kept your plant in the shade for a long time, and then abruptly put it in a bright place. In this case, it is not even necessary that direct Sun rays A simple change of scenery will suffice. In addition, sunburn can occur even if the leaf seems to stick to the glass.
Sunburn looks like a small reddish or yellowish dry spot on the surface of the leaf plate. Measures to save the hibiscus are best taken immediately, because the longer you delay, the more rehabilitation the flower will then need.
Treatment and prevention
In order to fix the problems, you will need to cure the plant, saving it either from the invasion of insects or from diseases. If in the case of insects it will be enough to apply any effective insecticide or acaricide (and for those who like to use folk remedies – soap solution), then with diseases you need to act a little differently.
In case of chlorosis, it is necessary to treat hibiscus with iron chelate and add necessary fertilizers(since the disease itself is often due to a lack of nutrients). In addition to improving the conditions of detention, you will not help the plant in any way.
In order to eliminate the effects of a sunburn, you need to remove all damaged hibiscus leaves, as well as optimize the conditions of detention - for example, put in a darker place.
To keep your hibiscus leaves safe and sound, follow these simple guidelines:
In this video, an expert will talk about how to save indoor plants from pests and diseases.
Hibiscus - beautiful and spectacular home plant, which has bright and big flowers. Without a doubt, many flower growers breed hibiscus in their home. However, hibiscus care must also be appropriate.
With proper care, hibiscus do not suffer from pests and diseases. But mistakes also happen to a grower with experience. The influence cannot be ruled out external factors: for example, the purchase of an already diseased plant in a store.
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Why indoor hibiscus does not bloom and what to do in this case
One of the common problems with hibiscus is the lack of flowering.
It may be related:
- with a lack of lighting - to lay buds, the plant must be in direct sunlight for at least 4 hours a day,
- lack of timely pruning - buds appear only on new shoots,
- pest damage,
- food shortage,
- lack of a dormant period in winter. From October to February, watering and top dressing are reduced, the temperature is lowered to 15-18 degrees. It is believed that flower buds are formed under these conditions. But the plant can bloom in winter, with sufficient lighting.
In order for the hibiscus to bloom, it should be provided with a sunny location, timely pinching and pruning of shoots, peace in winter and abundant top dressing in summer. It is also necessary to monitor the condition of the plant in order to notice pest damage in time.
Hibiscus pests
spider mite
One of the main enemies indoor hibiscus -. Collectors of varietal hibiscus are constantly at war with him, coming up with more and more new ways to fight. There are many drugs for the destruction of this pest, but the problem is that with regular treatment, ticks get used to them very quickly. Spider mite on hibiscus: photo The most popular insecticides: Fitoverm, or Kleschevit, which are quite safe for humans. Flower growers often use Actellik, but its vapors are poisonous, so this remedy is not recommended for indoor use. Preparations Sunmite and Neoron differ in that they destroy not only the mites themselves, but also their eggs, but these products are not sold in ordinary flower shops and often do not show much effectiveness.
Oddly enough, it is precisely “folk methods” that are effective against spider mites.. For example, spraying plants with water, with the addition of a few drops of any essential oil(5 drops per 1 liter of water). You need to do this regularly, every week. The method is safe for humans and destructive for ticks. But it is worth skipping one or two times of such processing - and the pests return.
By the way, if you add growth stimulants (for example,) or leaf fertilizers with each spraying, the result will be even better. Of course, drugs need to be alternated. Regular bathing of plants under a hot shower works in much the same way. Some hibiscus collectors spray the plants several times every day with warm water and wipe the window sills with soapy water.
These methods seem too energy-intensive from the outside, but when hibiscus collections are large and expensive, it is better to set aside one day a week for spraying or bathing in the shower than to lose plants due to a pest invasion.
Aphids on hibiscus
Such pests as are attracted by soft succulent shoots, its appearance on the plant immediately becomes noticeable due to sticky secretions and deformation of the foliage. Remove insects mechanically with a cotton swab and soap. Then the hibiscus should be treated with special chemicals: , Biotlin, Iskra or any others. Can be used folk methods, but they may not be effective enough. Processing is repeated several times, according to the instructions. Usually the plant is re-sprayed after 2 weeks. 
Gallica: why hibiscus buds fall
The fact that the hibiscus sheds buds may indicate an infection with a midge of gall midge. These pests lay their eggs in the buds, therefore, as a preventive measure, all yellowed buds must be removed before they themselves fall to the ground. The soil in a pot of hibiscus is treated with a soil pesticide.
The problem with buds can also be related to lack of lighting, uneven watering, lack of nutrition, drafts, and moving the hibiscus pot around the apartment.
Diseases of indoor hibiscus
Chlorosis or why hibiscus leaves turn yellow and fall off
One of the problems of hibiscus is leaf chlorosis, that is, loss of color. The leaf plate becomes pale green, almost yellow. The leaves may also begin to fall off. This is a sign of iron deficiency. The easiest way to bring back a rich color to the crown is to spray the plant with iron chelate. You should also change the fertilizer if it does not have enough microelements necessary for hibiscus. 
Chlorosis in hibiscus: photo Pick up good feeding for these plants it’s really not easy, because you often have to sort through various options.
Nutrient deficiencies (potassium, magnesium, zinc, sulfur)
The appearance of yellow spots, for example, after transplantation into new ground, may be caused by its lime content or lack of nutrients. Then you should replace the soil or use special preparations to make up for the lack of certain substances.
- With a lack of zinc, the leaves become smaller, specks appear on them.
- The lack of sulfur is expressed in the browning of the edge of the sheet.
- When there is little magnesium, chlorosis occurs between the veins - the so-called "marbling" of the leaf, sometimes with the appearance of dark spots.
- Potassium deficiency is expressed in the death of the edge of the leaf, which looks like a burn.
If the above methods do not work, the chlorosis may have been caused by viruses. Infections are carried by various pests, if such symptoms occur, you need to get rid of insects, and treat the hibiscus with fungicides.
sunburn
Hibiscus usually tolerate direct sunlight well. But if the plant stood in the shade for a long time, and it was placed in the sun without an adaptation period, sunburn may appear. They look like yellowish or red dry spots. Burnt leaves will have to be removed, and the flower should be accustomed to the sun gradually. It happens that the foliage is pressed against the glass - then a burn may also occur on it.
Also, sunburn main reason why do hibiscus leaves curl. 
Sunburn on hibiscus: photo The pledge of health hibiscus - proper care. Strong immunity allows the plant to cope even with pests and provides an attractive appearance and profuse flowering.
See also a useful video about caring for hibiscus in winter and summer:
