Content
Petunias can be found in the vast majority of home gardens. Gardeners value them for their variety of varieties and colors, wide possibilities for use in landscape design and general ease of care. Problems during cultivation arise quite rarely, but still the development of diseases and pest attacks cannot be ruled out. Therefore, you need to pay attention to suspicious symptoms, including sticky leaves on petunias.
Why are petunia leaves sticky?
A slight stickiness of leaves for some types of petunias is simply a varietal feature, and not a sign of disease. But if such a symptom appears on a plant for which it was not previously characteristic, this already means infection by 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 petunia, preferring the most delicate tissues (buds, blossoming leaves, upper parts of stems).
The affected tissues become covered with small “dots” that are clearly visible in the light. Then they become discolored, dry out, become deformed, and the petunia practically stops growing and dies. Sticky leaves are another sign of insect activity.Because of such secretions, aphids are actively “breeding” by ants. This is a favorable environment for the development of sooty fungus.
Gradually, the sticky coating on the leaves “overgrows” with black “powder”
If you do not fight aphids, the females lay eggs at the end of summer, which quietly overwinter in plant debris, the top layer of soil, and the next year, with almost one hundred percent probability, the stickiness of the leaves will appear in other plants planted in this place.
Spider mite
It is difficult to see this pest with the naked eye. But traces of his vital activity are much more visible. The above-ground part of the petunia is braided with thin, translucent threads reminiscent of a spider's web. The front side of the leaves is covered with almost colorless, gradually “blurring” spots, the back side is covered with sticky grayish-white secretions.
Petunia is infected from the bottom up - the pest lives in the soil. The color of a tick can be different - yellowish-beige, greenish, reddish-brown. The pest also feeds on plant juices, so the affected flower dries out and dies. If petunia leaves become sticky, this is a symptom signaling that the infection process has already gone too far and the spider mite has spread en masse.
Spider mite eggs in the soil remain viable for 4-5 years
Fungal diseases
Among fungal diseases, sticky leaves are characteristic of powdery mildew and gray rot.
With powdery mildew, a grayish or yellowish-white powdery coating that initially appears on petunia leaves turns into droplets of cloudy sticky mucus as the pathogenic microflora develops.
For gray rot, the first sign of the disease is “wetting” dark spots on the leaves and at the base of the stems. Then a gray “lint” appears on the fabrics, turning into a sticky brown-black coating.
Powdery mildew is a disease that is dangerous for the vast majority of garden crops - both ornamental and fruit-bearing ones.
The gardener himself is often to blame for the development of petunia rot; the reason is frequent watering.
What to do if your petunia has sticky leaves
Having discovered sticky leaves on a petunia, primarily based on a set of other symptoms, you need to identify the problem. Only in this case can an effective method of combating it be applied.
In the early stages of infection, it is quite possible to get rid of aphids on petunias using folk remedies. Individual insects and minor traces of sticky plaque are simply washed off with a stream of water with fairly strong pressure. You also need to take into account that aphids do not tolerate strong odors. It is useful to spray a flower bed with petunias with any strong-smelling infusion or solution. The following can be used as raw materials:
- garlic and onion heads, arrows;
- pine needles;
- sagebrush;
- tansy;
- marigold;
- tops of tomatoes or potatoes;
- peel of any citrus fruit;
- celandine;
- vinegar;
- ammonia.
Marigolds in a flowerbed 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 en masse throughout the flowerbed, all that remains is to use insecticides. Most universal broad-spectrum drugs will give the desired effect:
- Fitoverm;
- Tanrek;
- Iskra-Bio;
- Aktara;
- Karate;
- Confidor-Maxi;
- Arrow.
Spider mites are 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:
- Sunmite;
- Apollo;
- Omite;
- Neoron;
- Vertimek;
- Mites.
Spider mites quickly develop immunity to the product used. Since 3-4 treatments are required to destroy the pest with an interval of 5-12 days (the hotter it is outside, the more often), it is recommended to change the preparations.
If petunia is grown in a pot, you can get rid of spider mites without the help of chemicals
To limit the spread of infection, you must first remove all affected parts of the petunia, especially those with a sticky coating. They capture about another 0.5 cm of healthy tissue - most likely, the fungal mycelia have managed to spread to them.
In the early stages of infection, when only the first symptoms appear 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 flowerbed):
- baking soda or soda ash diluted with water (25 g/l);
- kefir or whey diluted 1:10 with added 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;
- Cuprosan;
- Ordan.
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 plaque on petunia leaves. Simple measures that a gardener can apply:
- Weekly plant inspection. This will help you notice the problem at an early stage of development and take timely action.
- Planting petunias according to the recommended scheme for a particular variety. If the flowerbed is “crowded,” it is not ventilated, and any problem spreads much faster.
- Compliance with watering standards. Both pathogenic microflora and pests thrive in moist soil. It is recommended to loosen the moistened soil for better access of oxygen to the roots.
- Application of nitrogen fertilizers according to the recommended fertilizing schedule and in the required dosage. Their excess negatively affects the immunity of petunia.
- Planting herbs and flowers with a pungent odor next to the flowerbed to repel aphids.
- Thorough cleaning of plant debris in the fall. It needs to be burned, and not stored somewhere on the site.
Conclusion
Sticky leaves on petunias may simply 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.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.
