How to Grow Vanda Orchids? Latest Cultivation Methods Explained in Detail
Vanda is the general term for plants in the genus Vanda of the orchid family, with about 50 original species and a very rich variety of hybrids. It is native to India, Malaysia, the Philippines and other places. Our country's experts translated it as “Wandai” probably meaning that it has strong vitality and can be passed down from generation to generation forever. Its ornamental value is very high, and it is a flower that can be enjoyed all year round. Now let us take a look at the cultivation methods for Vanda orchids!
Growth Habits of Vanda
Vanda fears cold but not heat, and fears waterlogging but not drought. In summer, temperatures as high as 35°C have little effect on its growth, and when cultivating it there is no need to use much potting medium. Many flower farms in Thailand grow Vanda very extensively; they often nail wooden strips into small square frames, put in a few pieces of charcoal, broken bricks or coconut husk, and it can continue to grow. Some even use only a nylon rope to tie up the plant and hang it in an orchid shed or under a tree, looking like a “hanging cured duck,” and by frequently sprinkling water and spraying fertilizer on it, it can still grow leaves and bloom.
Propagation Methods of Vanda
Vanda can be propagated by keikis. In late autumn, Vanda will grow keikis at the leaf axils. When the keikis grow to 5-7.5 cm, use a sharp and sterilized knife to cut the keikis off the mother plant and plant them in a pot filled with osmundine. They can be transplanted to a larger pot. Remember that the cut must be coated with medicine to avoid infection by pathogens. In addition, when a plant cultivated for many years grows to more than 1 m, the top bud about 30-46 cm long can be cut off, and both cut surfaces should be coated with medicine for disinfection, then planted in a pot and kept moist.
Cultivation Methods of Vanda
1. Potting soil: The roots of Vanda are aerial roots, and any well-drained medium can be used, such as osmundine, broken bricks, charcoal, coarse gravel, etc. Whether used alone or mixed together, they are all very good potting soil.
2. Light: Vanda usually needs relatively strong light. During the local high-temperature season, 40-50% shade netting is needed for shading, and in winter shading is not even needed.
3. Temperature: Vanda likes a high-temperature environment, and the most suitable temperature is 20-30°C. In summer, temperatures as high as 35°C have little effect on its growth.
4. Water and moisture: In daily management, Vanda must be ensured sufficient water and air humidity. In the rainy season, vigorous growth can be maintained by natural conditions. In the dry season, artificial sprinkling must be used to keep air humidity at around 80%.
5. Fertilization: Vanda requires more fertilizer than other tropical orchids, so during the vigorous growth period, diluted fertilizer can be applied once every 7-10 days. The best fertilizer has a nitrogen, phosphorus and potassium ratio of 10:10:5.
6. Repotting: Vanda should not be repotted frequently. Unless it is attacked by pests or diseases, it should be repotted only once at least every 3 years. In spring, Vanda is about to enter its vigorous growth period, which is a good time to repot.
Pest and Disease Control of Vanda
1. Phytophthora disease
[Symptoms] It can occur all year round, but in the plum rain season, when watering is too wet or ventilation is poor, the disease is most severe. Seedlings that have just come out of the flask are especially vulnerable. The infected parts produce brown lesions, which expand rapidly under high temperature and high humidity, eventually becoming dark brown spots, with leaves falling and stems rotting until the plant dies.
[Control] ① Avoid excessive moisture, improve ventilation and air circulation conditions, and ensure sufficient light. ② Avoid using only nitrogen fertilizer, and reduce weak excessive vegetative growth of plants. ③ Spray 1/800 carbendazim or 1/1000 Topsin liquid. ④ Coat the wound from cutting off diseased plants with Daconil powder, then place in a dry place and do not water for one week, which can check the spread of the disease.
2. Anthracnose
[Symptoms] It is easily contracted when planting is too dense, ventilation is poor, water regulation is disrupted, or wounds are present. In the early stage of the disease, small brown sunken spots appear on the leaves, which later expand into round or irregular lesions. In severe cases, gangrene appears in the center of the lesions.
[Control] ① Do not plant too densely, increase light, and ensure good drainage and ventilation. ② Cultivate strong seedlings, and do not frequently move plants, so as to avoid damage and infection. ③ Cut off diseased leaves, and apply 1/500 Daconil-45 liquid or 1/800 carbendazim to the wounds. ④ Spray 1/1000 thiophanate-methyl or carbendazim liquid once a week.
3. Soft rot
[Symptoms] This disease is more likely to occur in spring and summer under high temperature and high humidity, poor ventilation, and excessive application of nitrogen fertilizer. In the early stage, bacteria invade the leaves or heart leaves and produce water-soaked lesions, which expand rapidly and contain much water. In the later stage, a foul odor occurs, the diseased leaves turn yellow and fall off, and the whole plant rots softly and dies. The disease spreads extremely quickly and must be controlled as soon as possible.
[Control] ① Improve growing conditions, increase ventilation, and lower temperature and humidity. ② Cut off the infected parts, apply antibiotic powder, and do not water for one week, which can check the spread of the disease. ③ Use streptomycin 1000-fold liquid, lime sulfur mixture or Bordeaux mixture 500-fold liquid, and spray once a week.
4. Leaf blight
[Symptoms] Small black spots appear at the leaf tips and gradually expand into irregular lesions. The edges of the lesions form a dark brown color, while the center is light grayish brown. In severe cases, they spread over the entire leaf, and finally the leaf withers and falls.
[Control] ① Cut off diseased leaves and spray 500-fold Daconil-45 or 1000-fold Topsin. ② For infected plants, avoid rain or temporarily stop watering to prevent the condition from worsening. ③ Spray 500-fold Daconil-45 regularly once a day as a preventive measure.
5. Southern blight
[Symptoms] Vanda is relatively prone to this disease. In the early stage, the base of the pseudobulb turns black and rots, and white mycelium gradually appears on the lesions. The diseased plant gradually withers and dies.
[Control] ① Cut off the pseudobulbs with lesions and burn them together with the pots and planting medium used. ② Spray 500-fold Daconil-45 liquid, or 1000-fold carbendazim liquid, once a week.