Diseases and pests of geranium
Geranium is an extremely tolerant plant. It is known for being reliable and sturdy, requiring little maintenance. However, sometimes there may be problems with the health of the flower. Fortunately, there are not many pests that geraniums are attracted to, and most diseases are easily treatable. Therefore, do not rush to throw away your beautiful plants.
The consequences of improper care
When grown indoors, geraniums have special care requirements to ensure optimal growth and prevent disease. Without proper care, indoor geraniums are vulnerable to rot and mildew. These ailments can also attract some insect pests that commonly affect other houseplants.
Geranium decay occurs with excessive watering. Geranium tolerates dry soils better than excessively wet ones. And excessive watering leads to rotting of the plant. If the soil is dry to the touch at a depth of 10 to 15 cm, you can water the flower. If it is still slightly damp and cool, the plant no longer needs water.
Grow indoor geraniums in pots with drainage holes to prevent moisture build-up at the bottom.
Blooming disturbance occurs with improper lighting. Home geraniums that don't get enough light will have fewer flowers. Keep geraniums where the sun will shine most of the day. For example, on windows facing south or west. If you don't have a suitable window, move the plant outdoors (in summer) for a day, or supplement the flower's needs with artificial lighting. In addition, the following factors can lead to a lack of flowers.
- Reducing the room temperature... If the geranium is frozen, no flowering should be expected.
- The pot is too big, as a result of which the plant will spend all its energy on development.
- Excessive fertilization... Indoor geraniums usually do not require frequent fertilization. Planting geraniums in a potting mix that contains 1 part soil, 1 part sand, and 1 part peat will provide sufficient nutrition for the first 2–3 months of growth. After that, use a water-soluble fertilizer with a nitrogen-potassium composition in equal proportions and at the rate of 1 teaspoon per 4 liters of water. If the geranium is kept indoors all year round, fertilize only during the growing season.
- Lack of nutrients in the ground.
- Violation of pruning shoots.
Improper care is quite capable of leading to disease. For example, swelling appears as leaf spots that later turn corky and brown. Leaves may turn yellow and fall off. Edema is caused by excessively wet, warm soil and moist, cool air, or it is due to the fact that the roots absorb more water than the leaves. As a result, the cells swell and burst. Therefore, avoid excessive watering and hyperventilation in the apartment.
Yellowing of leaves occurs with insufficient watering, drying also occurs due to insufficient watering of the plant.
It is worth remembering that any violation of the rules of care contributes to the activation of pathogens of various flower diseases.
Major diseases
Geraniums can attack a variety of diseases, most of them affect the leaves and trunk of the plant.
Trunk
The most common enemy of indoor geranium is rot. Most often, the defeat occurs in very hot weather. The disease occurs if the plant dries up and then watered abundantly.Signs of rot - the appearance of gray, fluffy spots on the trunk and leaves, if nothing is done, the plant will die.
Stem rot starts with one or two branches showing that the plant is drying out. At the end, the entire stem turns black and only a few leaves remain. Inside the stem, the vascular fibers remain intact, but the supporting tissue around the fibers is destroyed. The first prophylaxis can be carried out even at the breeding stage, when the cuttings are treated with fungicides.
Blackleg disease affects cuttings and young plants. Stems and petioles turn black at the root. Rotting starts at the base of the stem and can spread much higher. Without treatment, the plant will dry out, rot and die. Symptoms progress rapidly. For treatment, you can apply sterilization of the potting mixture and tools, also treat the cuttings with a fungicide.
Soil fertilization can slow the spread of the disease.
Leaves
- Leaves are most often affected by a fungus.... On flowers, petals darken at the edges and dry out prematurely. If the humidity is high, accumulations of spores can be found practically on the entire surface of the plant. The spots on the leaves are of various shapes, brown.
- Rust is quite common on geraniums.... Distinct, reddish, circular pustules form on the undersides of the leaves. Rust can negatively affect zoned varieties. Nowadays, it is widespread, especially during the wet summer or fall. The disease does not infect the culture very quickly, so there is time to cure it. Rust Prevention - Removing infected leaves and spraying with fungicide.
- With bacterial blight, leaf damage begins on the underside.... The spots become well-defined within a few days, the leaves curl inward. This is followed by necrosis and the leaf dries. Another symptom is that the leaf edge wilts, resulting in an angular venous pattern. Leaves fall off over time.
- Dropsy often affects older leaves and is caused by irregular watering... If the plants are quite dry and then watered abundantly, the mouths on the back of the leaves do not always cope with their function and burst. After that, they become stale and look like scars.
If you remove all the leaves that look unsightly, then new ones will grow in their place. New leaves will no longer have such problems.
Yellowing of the lower leaves of geraniums can occur for one of the following reasons.
- Not enough light for the bottom of the plant. The problem arises if the plants are too close to each other or too far from the light source.
- Plants receive little water at the roots. Although the entire family of pelargoniums can rot in excessively humid environments, it is a mistake to think that they need to be kept dry at the roots. When dry, the stems become hard and woody.
- Plants "drown" in water. Too much liquid will prevent oxygen from reaching the roots, causing them to die. According to some reports, 90% of indoor plants die from over-watering. Never be afraid to remove the plant from the pot to see what happens to the roots.
Pests
In addition to diseases, indoor geraniums are also susceptible to attacks by harmful insects.
- Whitefly. It is a small white butterfly that damages the plant. The adult and its larvae consume the plant sap, damaging it. The leaves become colorless, perform poorly, and the plant gradually disappears.
- Aphid. These green flies are even more problematic than whiteflies, as they can destroy leaves and spread quickly. Spray the entire plant with a special spray, especially under the leaves. If possible, it is best to isolate the plant to stop the spread of aphids. Or spray absolutely all the flowers in the house to protect them.
- Sciarids. These are black flies that can be seen on the soil surface. Their larvae damage the roots. They can thrive in peat composts, but are usually not active enough to kill plants. Their life cycle lasts for about two months a year. And along with the flies, troubles disappear. If there is no time to wait, any insects are successfully destroyed with insecticides.
- Caterpillars. It is impossible to say exactly which caterpillar can attack geraniums, because they come from a variety of insects. They feed on leaves, gnawing holes in them. Control measures are the same insecticides.
Worms, snails, slugs and ticks rarely affect geraniums.
Treatment
Let's consider some successful methods on how to deal with various diseases of geranium.
Disease | Prevention and treatment measures |
Alternaria | Avoid watering from above. Remove and discard crop residues. Apply a fungicide to save the plant. |
Bacterial rot | Buy healthy cuttings or grow plants from seeds to fight and prevent disease. Once the diagnosis is made, it is necessary to immediately get rid of the infected plants in order to prevent re-infection. Avoid overhead watering. |
Bacterial fascia | Buy healthy cuttings from a reputable manufacturer, or grow plants from seed. Remove infected plants and cuttings. |
Blackleg | Use sterile propagation media. Discard infected cuttings, as affected root cuttings will later develop root rot, which will have to be treated again. |
Gray rot | Avoid any damage to the plants. Remove and discard wilted flowers and leaves. Place your plants for good air circulation and low humidity. Apply a fungicide to revive the plants. The use of only one chemical can lead to the development of populations resistant to that chemical. Don't rely on just one chemical. |
Dropsy | The plant must be provided with good air circulation. Avoid overflow in cool, cloudy weather. |
Leaf spot | Buy cuttings without diseases. Do not water the geraniums from above and always keep the surface of the leaves dry. |
Root rot | For this condition, try treating the plant with a fungicide. If there is no result, feel free to throw away the sick specimen. |
Rust | Purchase healthy cuttings and avoid overhead watering. Avoid buying geraniums at the end of the season. |
Pelargonium vertical wilt | Use sterile potting mix and destroy infested plants in a timely manner. |
Viruses | Buy plants from trusted manufacturers. Unfortunately, almost all viruses cannot be cured. |
Care Tips
When buying geraniums, experts recommend looking for plants with healthy leaves, no spots on top or bottom, and no rough stems that indicate that specimens grew in poor light. Consider some additional tips for caring for geraniums.
- Geraniums need at least six hours of sunshine every day for best growth and flowering. It must be protected from freezing. During the hottest part of summer, plants do their best in the afternoon.
- When planting in a garden, plant the plants about 25 cm apart in fertilized garden soil.
- Fertilize the geranium every two weeks and water it when the soil is dry to a depth of 5 cm. Remove old flowers to keep the plants looking fresh.
- If the garden is not too sunny, you can still enjoy the flowers. You just have to move the pots in the sun from time to time.
- Choose containers with drainage holes at the bottom or sides. Plant the plants in an ultra-light mixture with lots of peat and vermiculite. Geranium needs good drainage, but avoid using a saucer under the pot. Let the water drain completely from it.
If you want to keep a healthy flower and help it survive the winter, then these recommendations can be applied here.
- Take cuttings in the fall and keep them in small pots on a south-facing windowsill during the winter.
- The old method of overwintering geraniums is to dig up the plants before the first freeze, knock the soil off the roots and hang the plants upside down in a cool room with a humidity of 80% and a temperature of +5 degrees. If the plants start to dry out, soak the roots in water several times each winter. In the spring, cut the plants, cut half off the top, and transplant to open ground.
For information on what diseases and pests of geranium exist, see the next video.
Hello. I have some other disease on my flowers, nothing is said about it here. White bloom, like a fungus on the stem. Tell me what to do?
Larissa, perhaps a mealybug, which is hidden under a white sticky substance, like cotton wool. Since the worm quickly passes to other plants, the bush must be urgently isolated when the first signs of damage are detected. You can remove the pest manually with a damp cloth, and then rinse with a soap-alcohol solution (20 ml of alcohol, 20 g of laundry soap per 1 liter of water). In case of severe infection, the use of insecticidal preparations ("Actellik", "Aktara", etc.) is recommended.
Brown spots appear on the leaves, then the leaf turns completely brown and falls off.
Indira, the plant can be affected by brown spots, both due to viral or bacterial diseases, and for other, quite common reasons. If the geranium is clearly affected by the disease, then you need to transplant it into another soil, water it strictly in the morning and treat it with fungicidal mixtures. But the characteristic brown spots on the leaves of a flower can also appear from the fact that the flower has grown, and the flowerpot has become cramped for it, or the soil in the pot is poorly drained, or perhaps the plant is in a draft.
Hello! My geranium is constantly blooming, and the leaves do not grow, they turn red and fall off. What could it be?
One of the reasons for this phenomenon is low air temperature. The comfortable temperature for this flower is + 21 ... + 25 ° C. +18 ° C is considered a critical mark - it is at this temperature that geranium leaves begin to blush around the edges, after which they fall off.
Indeed, the window is always ventilated in the room. And after the end of the heating season, the room became cooler. I'll put it away from the open window. Thanks!
It blooms well for me, but for some reason the flowers are covered with a brown bloom, similar to mold ...
On a street geranium, on an unblown bud, I have bright green eggs, tightly touching each other. What is it, really, aphid?
The comment was sent successfully.