Petunias can be found in the vast majority of household plots. Gardeners appreciate them for the variety of varieties and colors, wide possibilities of use in landscape design and general ease of maintenance. Growing problems arise quite rarely, but nevertheless, the development of diseases and pest attacks are not excluded. Therefore, you need to pay attention to suspicious symptoms, including sticky leaves in petunias.
Why are petunia leaves sticky
A slight stickiness of leaves for some petunias is just a varietal feature, and not a sign of disease. But if such a symptom manifests itself on a plant for which it was not previously characteristic, this already means infection with pathogenic fungi or attack by pests.
Aphids feed on plant juices. Small oval insects of pale green, yellowish, black-brown color literally stick around the petunia, preferring the most delicate tissues (buds, opening leaves, upper parts of the stems).
The affected tissues are covered with small "dots", clearly visible in the light. Then they discolor, dry out, deform, petunia practically stops growing and dies. Sticky leaves are another sign of insect activity. Because of such secretions, ants actively "breed" aphids. This is a favorable environment for the development of a sooty fungus.
Gradually, the sticky bloom on the leaves "overgrows" with black "powder"
If you do not fight aphids, females lay eggs at the end of summer, which calmly overwinter in the plant debris, the upper layer of the soil, and next year, with almost one hundred percent probability, the stickiness of the leaves will also appear in other plants planted in this place.
Important! Aphids and ants are a very stable symbiosis. If there are many anthills next to the petunia flower bed, it is extremely difficult to get rid of it.
It is difficult to see this pest with the naked eye. But the traces of his vital activity are much better discernible. The aerial part of the petunia is braided with thin, translucent threads resembling a spider web. The front side of the leaves is covered with almost colorless, gradually "spreading" spots, the back side is covered with sticky grayish-white secretions.
Petunia infection goes from bottom to top - the pest lives in the soil. The color of the tick can be different - yellowish-beige, greenish, reddish-brown. The pest also feeds on plant juices, so the affected flower dries up and dies. If the leaves of the petunia become sticky, this is a symptom signaling that the infection process has gone too far, the spider mite has spread en masse.
Spider mite eggs in the soil remain viable for 4-5 years
Of fungal diseases, leaf stickiness is characteristic of powdery mildew and gray rot.
With powdery mildew, the powdery coating of a grayish or yellowish-white color initially appearing on the leaves of petunia turns into drops of cloudy sticky mucus as the pathogenic microflora develops.
For gray rot, the first sign of the disease is “weeping” dark spots on the leaves and at the base of the stems. Then a gray "pile" appears on the fabrics, turning into a sticky brown-black bloom.
Powdery mildew is a disease that is dangerous for the vast majority of horticultural crops, both decorative and fruiting
Important! The stickiness of petunia leaves signals that the process of infection with pathogenic fungi has gone very far. Most likely, the damaged plant can no longer be saved.
In the development of petunia rot, the gardener himself is often to blame, the reason is frequent watering
What to do if petunias have sticky leaves
Having found sticky leaves in petunia, first of all, by a set of other symptoms, you need to identify the problem. Only in this case can an effective way of dealing with it be applied.
In the early stages of infection from aphids on petunias, it is quite possible to get rid of folk remedies. Individual insects and minor traces of sticky plaque are simply washed off with a jet of water with a fairly strong pressure. You also need to consider that aphids do not tolerate strong odors. It is useful to spray a petunia flower bed with any strong-smelling infusion or solution. As raw materials, you can use:
- garlic and onion heads, arrows;
- tops of tomatoes or potatoes;
- peel of any citrus;
Marigolds on a flowerbed with petunias look very cute and protect her from aphids
If the sticky bloom on the petunia has already turned into drops falling from the leaves, and the aphid has spread en masse through the flower bed, it remains to use only insecticides. The desired effect will be given by most universal drugs with a wide spectrum of action:
Important! A solution of any drug is prepared strictly according to the instructions. As a rule, 2-3 treatments with an interval of 12-14 days are enough to get rid of aphids on petunias and leaf stickiness.
The spider mite is practically immune to folk remedies. Therefore, to combat it, you must immediately use chemicals. This is not an insect, special preparations are required - acaricides or insectoacaricides:
The spider mite quickly develops immunity against the agent used. Since it takes 3-4 treatments at intervals of 5-12 days to destroy the pest (the hotter it is outside, the more often), it is recommended to change the preparations.
Important! The pest does not tolerate high humidity. If sticky leaves are found on a petunia grown in a pot or planter, you can simply water it abundantly and cover it on top for 2-3 days with a plastic bag, as tightly as possible.
If the petunia is grown in pots, you can get rid of the spider mite without the help of chemicals.
To limit the spread of the infection, it is necessary to first remove all affected parts of the petunia, especially those on which a sticky coating is visible. They capture another 0.5 cm of healthy tissue - most likely, the mycelium of the fungus managed to spread to them.
In the early stages of infection, when only the first symptoms appeared on the petunia, but not the stickiness of the leaves, folk remedies are suitable (they need to treat both the plant itself and the soil in the flower bed):
- baking soda or soda ash diluted with water (25 g / l);
- diluted 1:10 kefir or milk whey with the addition of iodine (2-3 drops per liter);
- bright pink solution of potassium permanganate;
- laundry soap foam.
To combat diseases, antifungal drugs are used - fungicides:
To prevent the spread of infection, all affected parts of the petunia are cut off with a disinfected instrument.
Important! Also, copper sulfate or Bordeaux liquid is used to combat powdery mildew and gray rot. It is copper compounds that are detrimental to pathogenic microflora.
Regular prophylaxis is much easier than tackling the sticky bloom on petunia leaves. Simple steps a gardener can take:
- Weekly plant inspection. This will help to notice the problem at an early stage of development and take action in time.
- Planting petunias according to the scheme recommended for a particular variety. When "crowded", the flower bed is not ventilated, any problem spreads much faster.
- Compliance with watering standards. In moist soil, both pathogenic microflora and pests feel good. It is recommended to loosen the moistened soil for better oxygen access to the roots.
- Application of nitrogen fertilizers according to the recommended feeding scheme and in the required dosage. Their excess negatively affects the immunity of petunia.
- Landing next to a flower bed of herbs, flowers with a pungent smell to scare away aphids.
- Thorough cleaning of plant debris in the fall. It needs to be burned, not stored somewhere on the site.
Important! If possible, petunias with a sticky bloom on the leaves should be isolated from other plants to stop the spread of pests or pathogens.
The sticky leaves of petunias may just be a feature of the variety. But more often the appearance of a sticky plaque signals a pest attack. This symptom is also characteristic for some fungal diseases. In order to prevent the death of plants, it is necessary to constantly examine them for the presence of suspicious symptoms, be able to identify the problem and know how to cope with it.