Perennial garden geraniums are unpretentious. If they are planted in a place suitable for this species, drought-resistant – in the sun in well-drained soil, moisture-loving – in partial shade in moist soil, there are usually no problems when growing, plants can grow without transplanting up to 10-15 years. Diseases and pests affect geraniums rarely and insignificantly, almost never leading to their death.
Sometimes in cold and wet years, fungal diseases appear on plants: powdery mildew, brown spot, gray rot. Sick leaves and stems must be cut and burned, with powdery mildew, treat with Bordeaux mixture, with gray rot and brown spotting – with any fungicide. For the prevention of diseases immediately after flowering or at the beginning of the death of the leaves, they are recommended to be cut. When pruning after flowering, new shoots appear, some species bloom again.
Due to the tough, pubescent leaves rich in essential oils, pests usually do not infect the crop. In rare cases, in hot, dry weather, a spider mite may appear, to combat which any insecticide is used, but usually it is enough to treat the lesions, stems and internodes with soapy water.
Indoor geraniums, with proper care, also rarely get sick. Geranium diseases and damage by pests are usually the result of improper maintenance – lack of lighting, high humidity or dryness of air and soil, and violations of the temperature regime. The appearance of a flower can tell which of the adverse factors is affecting it at the moment.
Why geraniums get sick: the leaves dry and turn yellow
If the geraniums dry and fall off the lower leaves, the stem is exposed, which means that the plant does not have enough light. It must be moved to a more illuminated place, for example, to the south window, in winter – to organize additional lighting with a fluorescent lamp.
It is more difficult to answer the question of why geraniums turn yellow. There may be several reasons. If the leaves turn yellow at the top of the bush, become lethargic, rot, then the plant experiences an excess of moisture. Reduce watering. This indoor flower is watered only when the clod of earth in the pot is completely dry to the touch, and excess moisture is drained from the pan.
When geranium leaves turn yellow, located below, while they remain elastic or dry only at the edges, this indicates a lack of moisture. Watering needs to be increased.
Sometimes the leaves turn yellow when a flower is transferred from an open ground or from a balcony to an enclosed space. In this case, after acclimatization, yellowing stops.
In too hot weather, you can watch the geranium leaves turn yellow or white. Usually, therefore, high temperature affects the young growth of leaves, in the future they will dry out and fall off, so in summer it is better to shade the plants from the bright midday sun.
If the geranium leaves turn red around the edges, the likely cause is low temperatures. The flower must be moved away from the window or moved to a warmer place, providing it with a temperature of about 18 ° C. Reddening of geranium leaves may also indicate a lack of nutrition, in which case the plant should be fed or transplanted.
The cause of the discoloration of the leaves is a common fungal disease, rust, which leads to the appearance of yellowing spots on them and their further drying. Sometimes plants become covered with mold, which indicates a defeat by gray rot caused by the fungus Botrius. In the presence of such signs, treatment with special preparations – fungicides is necessary.
The risk of fungal diseases increases with waterlogging of the soil. It also causes such a non-infectious disease as edema, in which soft watery pads appear on the leaves. For prevention, it is necessary to ventilate the room more often, reduce watering.
Planted cuttings and seedlings of geraniums, under adverse conditions, are affected by the black leg. To avoid this, it is necessary to plant plants in disinfected soil. Sterilizing the soil during transplantation will also help prevent the occurrence of viral diseases.
A dangerous disease that causes the death of a flower is a root nematode, manifested in the formation of large nodes on its roots. Affected specimens are destroyed, the soil is thrown away, since it cannot be used for any other plants.
Of the pests on the leaves, aphids, mites and whiteflies can appear. To destroy aphids, the flower can be washed with a solution of laundry soap, and the crown is thoroughly rinsed from ticks with running water. The whitefly is more dangerous, the appearance of which is promoted by high temperature and dry air. This pest very quickly adapts to pesticides, to destroy it, the preparations must be alternated, so it is better to prevent the appearance of whiteflies on house plants at all.
Why does geranium not bloom at home?
Another problem that arises when growing indoor geraniums is the lack of flowering.
The reasons why geraniums do not bloom may be as follows:
- if the plant has stopped blooming in the fall, you should not worry, most likely, it has a dormant period, the flower must be cut, watering and fertilizing should be reduced;
- if the bush looks healthy, the lack of flowering is most likely caused by a warm wintering;
- too large a pot also does not contribute to lush flowering, which begins only after the roots completely fill the container;
- finally, unfavorable conditions, namely, lack of lighting, low temperature, lack of top dressing and pruning also delay the flowering of geraniums.