Latest Cultivation and Management Techniques and Methods Tutorial for Impatiens walleriana
In the application of herbaceous flowers in Europe and America, Impatiens walleriana ranks first. It offers a wide range of bright colors and grows vigorously with simple management. It is suitable for tray and box containers, hanging baskets, flower walls, window boxes and balcony cultivation. A germination rate of over 90% in plug trays has meant that impatiens has consistently performed better than other series of varieties in all plug tray quality parameters, flowering earliest, with the richest colors and free branching. The plants are covered with large masses of flowers, creating a superb flowerbed and flower border landscape, with a plant height of 20-25 cm. The colors of the leaves and flowers are very vivid and richly varied, with more than 40 colors in total. Against the shaded background of the garden, the colors are harmonious, well-proportioned and delicate, enriching and adding depth of tone to the flowers.
Cultivation and Management
The potting soil should be a loose, fertile sandy loam. For example, using 1/2 peat soil or leaf mold mixed with 1/2 sandy loam plus some decomposed cake fertilizer powder or commercially available chicken manure is even better. Such soil is loose and fertile, more suitable for plant growth, and also beneficial to the growth of the root system of young plants. When the seedlings are at the 2-leaf stage, they can first be pricked out once, and when they are about 4 cm tall, they are planted in flower pots. When planting, it is best to choose a cool, humid environment for placement, to help the seedlings recover and survive, and also to help them bloom earlier. After the plants have established and survived, they can be pinched once to promote side shoots, which is beneficial for more branching and more flowering. Growth is slow at the seedling stage, but they have the characteristic of being able to bloom as small seedlings. As the seedlings grow, fertilizer and water management should be strengthened, and a dilute organic liquid fertilizer or 0.3% compound chemical fertilizer can be applied every 10 days. This flower likes warmth and humidity and dislikes strong light. It is best placed in a spot with half a day of light or 70% light, with frequent water spraying around it, which keeps the plants full and blooming continuously. Large Impatiens walleriana likes half-day light conditions, and sun-tolerant varieties have now been successfully bred, such as the Expo series, which can also grow well under full sun, so they are also suitable for flowerbed planting.
Because Impatiens walleriana likes semi-shade, it is very suitable for growing on a home balcony or windowsill or in the shade of trees in a courtyard. Old plants show degeneration in flowering, and the plants also look less attractive, so new plants should be replaced through cuttings, and pruning should also be noted.
1. Planting: Generally sown in spring from March to April. They can be sown in a seedbed, or sown directly in a courtyard flowerbed. The seedlings grow quickly, so thinning should be done in time, and after 1 transplanting they are planted out in the garden in early June. If sowing is delayed and the seedlings are potted, they can bloom around National Day.
2. Light and temperature: It likes light and is also shade-tolerant, and needs to receive at least 4 hours of scattered sunlight every day. In summer, shading should be provided to prevent excessively high temperatures and scorching sun exposure. The suitable growth temperature is 16-26°C, and the ambient temperature during the flowering period should be kept above 10°C. In winter, it should be moved into a greenhouse to prevent cold and freezing.
3. Watering and fertilizing: Water should be given promptly after planting. During the growing period, attention should be paid to watering, keeping the potting soil moist regularly, especially in summer when more watering is needed, but waterlogging and long-term excessive soil moisture must be avoided. If there is a lot of rain, attention should be paid to drainage to prevent waterlogging, otherwise the roots and stems are prone to rot. After planting, fertilizing should be frequent, and special care should be taken not to let the soil alternate between dry and wet. In summer, never water wilted plants under the scorching sun. Especially during the flowering period, they must not suffer drought, otherwise the flowers are prone to drop.
4. Flowering period control: If you want to delay the flowering period, you can sow in early July. You can also use the method of pinching, while removing early-opening flowers and flower buds, so that the plants keep growing larger, with topdressing once every 15 - 20 days. After September, more flower buds will form, so that they bloom around National Day.
Pest and Disease Control
Brown spot disease and powdery mildew sometimes occur, and 50% carbendazim can be sprayed for control.
1. Impatiens walleriana powdery mildew
Symptoms: This disease mainly occurs on the leaves and tender shoots. It generally begins to occur in June, and after July the leaf surface is covered with a white powdery layer. Subsequently, small yellow grains form in the white powdery layer, and the color gradually deepens, finally becoming dark brown. Transmission route: The pathogen overwinters in diseased plant residues and seeds. The following year, when the environment is suitable, the pathogen spreads by wind and rain. August to September is the peak period of the disease.
[Control methods] Do not plant too densely, provide appropriate ventilation, strengthen fertilizer and water management, and enhance the disease resistance of the plants. Remove diseased leaves and diseased plants and destroy them centrally to reduce sources of infection. During the disease period, use 15% triadimefon wettable powder at 1000-1200 times dilution, or 70% thiophanate-methyl wettable powder at 1000 times dilution for control. Avoid spraying at high temperatures above 32°C to prevent phytotoxicity.
2. Impatiens walleriana brown spot disease
Impatiens walleriana brown spot disease is also called impatiens leaf spot disease. Symptoms: The disease mainly occurs on the leaves. The lesions on the leaf surface are initially light yellowish-brown small spots, then expand into round or oval shapes, after which the center becomes light brown and the edges brown, with inconspicuous concentric rings. On severely affected leaves, the lesions merge into patches, causing the leaves to become withered and yellow, until the plant dies. Transmission route: The pathogen overwinters on impatiens diseased residues and soil plant debris. The following year, when environmental conditions are suitable, the pathogen spreads by wind and rain. It is prone to occur in hot and rainy seasons.
[Control methods] Impatiens walleriana likes fertile sandy loam and is not tolerant of waterlogging. Therefore, sandy loam is suitable for planting to facilitate drainage; for potted Impatiens walleriana, pots should be tipped promptly after rain. In late autumn, diseased leaves and diseased plants should be destroyed centrally to reduce sources of infection for the coming year. In the early stage of the disease, use 25% carbendazim wettable powder at 300-600 times dilution, or 50% thiophanate-methyl at 100 times dilution, or 75% chlorothalonil at 1000 times dilution for control.
3. Impatiens walleriana damping-off disease
Symptoms: The pathogen mainly infects the root and stem area, causing the diseased area to turn black or constrict, and when moist, white mold-like substances grow on it. After the plant is infected, within a few days the leaves wilt and dry up, and then the entire plant dies. It mainly overwinters in the form of mycelium or sclerotia in the soil or in diseased residues. The mycelium in the soil lives saprophytically and does not dormancy. In the field, it is mainly spread by contact, that is, when the roots, stems and leaves of the plant contact diseased soil, they are infected by the mycelium in the soil. Under conditions with a water film, healthy leaves in contact with diseased parts become infected. In addition, seeds, farm tools and contaminated compost can all cause the disease to spread and expand.
[Control methods] In the early stage of the disease, after removing the diseased plants, spray 75% chlorothalonil wettable powder at 600 times dilution, or 60% carbendazim · thiram wettable powder at 500 times dilution, or 20% tolclofos-methyl emulsifiable concentrate at 1200 times dilution.