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Petunias can be found on the vast majority of personal plots. Gardeners appreciate them for the variety of varieties and colors, wide possibilities of use in landscape design and general unpretentiousness in care. Growing problems are quite rare, but 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 the leaves for some types of petunia is just a varietal feature, and not a sign of a disease. But if such a symptom appears on a plant for which it was not previously characteristic, this already means an infection with pathogenic fungi or an attack by pests.
Aphid attack
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, blossoming 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, the petunia practically stops growing and dies. Sticky leaves are another sign of insect activity. Because of such secretions, aphids are actively “bred” by ants. This is a favorable environment for the development of soot fungus.
Gradually, the sticky coating on the leaves “overgrows” with a black “powder”
If you do not fight aphids, females lay eggs at the end of summer, which will quietly overwinter in plant debris, the upper layer of soil, and next year, with almost XNUMX% probability, the stickiness of the leaves will also appear in other plants planted in this place.
spider mite
It is difficult to see this pest with the naked eye. But the traces of his life are much better distinguishable. The aerial part of the petunia is braided with thin, translucent threads resembling a cobweb. The front side of the leaves is covered with almost colorless, gradually “blurring” spots, the underside 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 the juices of the plant, so the affected flower dries up and dies. If the petunia leaves become sticky – this is a symptom that signals that the infection process has already gone too far, the spider mite has spread massively.
Spider mite eggs in the soil remain viable for 4-5 years
Fungal diseases
Of the fungal diseases, leaf stickiness is characteristic of powdery mildew and gray rot.
With powdery mildew, a powdery coating of a grayish or yellowish-white color, which initially appears on the leaves of a 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 coating.
Powdery mildew is a disease that is dangerous for the vast majority of horticultural crops – both ornamental and fruiting.
The gardener himself is often to blame for the development of petunia rot, the reason is frequent watering.
What to do if the petunia has sticky leaves
Having found sticky leaves in a petunia, first of all, by a complex of other symptoms, you need to identify the problem. Only in this case it is possible to apply an effective way to deal with it.
In the early stages of infection, it is quite possible to get rid of aphids on petunias with folk remedies. Individual insects and slight traces of sticky deposits are simply washed off with a stream 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 flower bed with petunias with any strong-smelling infusion or solution. As a raw material you can use:
- garlic and onion heads, arrows;
- needles;
- sagebrush;
- tansy;
- marigold;
- tops of tomatoes or potatoes;
- peel of any citrus;
- celandine;
- vinegar;
- ammonia.
Marigolds in a flower bed with petunias look very pretty and protect it from aphids
If the sticky coating on the petunias has already turned into drops falling from the leaves, and the aphids have spread massively throughout the flower bed, it remains to use only insecticides. The desired effect will give the majority of universal broad-spectrum drugs:
- Fitoverm;
- Tanrek;
- Iskra-Bio;
- Aktara;
- Karate;
- Confidor-Maxi;
- Arrow.
The spider mite is practically immune to folk remedies. Therefore, to combat it, it is necessary to immediately use chemicals. This is not an insect, special preparations are required – acaricides or insectoacaricides:
- Can’t count;
- Apollo;
- Omait;
- Neoron;
- Vertimek;
- Kleshchevit.
Spider mite quickly develops immunity against the agent used. Since 3-4 treatments with an interval of 5-12 days are required to destroy the pest (the hotter it is outside, the more often), it is recommended to change the preparations.
If petunias are grown in pots, you can get rid of spider mites 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 that show a sticky coating. They also capture about 0,5 cm of healthy tissue – most likely, the mycelium of the fungus has 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 process both the plant itself and the soil in the flower bed):
- diluted with water food or soda ash (25 g / l);
- diluted 1:10 kefir or 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:
- Topaz;
- Speed;
- Horus;
- Maksim;
- Cuprozan;
- Order.
To prevent the spread of infection, all affected parts of the petunia are cut off with a disinfected tool.
Prevention
Regular prevention is much easier than dealing with sticky coating on petunia leaves. Simple steps a gardener can take:
- Weekly inspection of plants. This will help to notice the problem at an early stage of development and take timely action.
- Planting petunias according to the scheme recommended for a particular variety. With “crowding” the flower bed is not ventilated, any problem spreads much faster.
- Irrigation compliance. In moist soil, both pathogenic microflora and pests feel good. Wet soil is recommended to be loosened for better oxygen access to the roots.
- Application of nitrogen fertilizers according to the recommended top dressing scheme and in the right dosage. Their excess negatively affects the immunity of the petunia.
- Planting next to the flower bed of herbs, flowers with a pungent odor to repel aphids.
- Thorough cleaning of plant debris in the fall. It needs to be burned, not stored somewhere on the site.
Conclusion
The sticky leaves on petunias may just be a feature of the variety. But more often, the appearance of a sticky coating signals an attack by pests. This symptom is also characteristic of some fungal diseases. In order to prevent the death of plants, it is necessary to constantly inspect them for suspicious symptoms, be able to identify the problem and know how to deal with it.