How to cultivate Dendrobium in autumn
An introduction to the cultivation of Dendrobium in autumn and the maintenance points of potted Dendrobium orchids, the specific content is as follows:
Dendrobium autumnale is native to Southeast Asia and the Western Pacific islands, including Australia and Papua New Guinea, and is an evergreen orchid. Dendrobium autumnale is a sympodial orchid, with a plant height of 30-100cm, leaves that are lanceolate, elliptical to oblong, thick and leathery with a glossy finish. It has rhizomes or pseudobulbs, with pseudobulbs being the swollen part of the stem where the inflorescence emerges. The inflorescence is usually racemose, emerging from the top of the stem, and can form 1-3 peduncles, with an inflorescence length of 30-60cm, each branch capable of bearing 4-18 flowers, and some species like the goat's horn Dendrobium can have 20-30 flowers. The flowering period is mostly in autumn, with the natural flowering period from August to November, peaking in September and October. Dendrobium autumnale has a rich variety of flower colors including purple, light purple, pink, brown, white, yellow, green, and bicolor.
Due to its beautiful flower shape and numerous varieties, it has a long vase life as a cut flower and is not only an important cut flower variety in the orchid family but also a significant ornamental potted plant. It is considered to be the most promising commercial orchid variety after Phalaenopsis and Cattleya.
Dendrobium autumnale is a typical tropical orchid, suitable for growth in areas where the minimum temperature does not drop below 16°C, hence the industry is very developed in Southeast Asian regions like Thailand and Singapore, as well as in Hawaii, USA. In the mid-1970s, Dendrobium autumnale became widely popular as a cut flower product in Thailand, and later, Thailand, Singapore, and Hawaii became the main producing areas for cut Dendrobium orchids. In the past decade, Dendrobium autumnale has increasingly been used as a potted plant for indoor gardening in hotels and restaurants, offices, homes, and various occasions as gifts. Due to its characteristics such as numerous flowering branches, variable flower colors, shapes, and sizes, and long flowering period, it is superior to other orchids of other types as a potted plant. The main sources of Dendrobium autumnale cut flowers and potted plants are from Thailand and Hawaii. There are many varieties of Dendrobium autumnale, which can be selected according to market needs and season.
Breeding
Tissue culture of Dendrobium can be propagated through aseptic sowing or by using top or side buds to proliferate into protocorm-like bodies. Compared to external explant propagation, it has advantages such as simpler operation, faster speed, lower cost, and good virus elimination. Thailand, the Philippines, Singapore, etc., are the main production areas for Dendrobium tissue culture seedlings, and in recent years, the southern region of China has also started mass production of tissue culture seedlings. It takes 2-3 years of growth from tissue culture to commercial flowers.
Division select Dendrobium plants that have been planted for 2-3 years and are full of pots, remove them from the pot, divide the pseudobulbs, and prune the old roots, then plant 3-4 plants as a clump in a plastic pot with a diameter of 15cm.
Division should be carried out when the new buds of the orchid plant start to grow. After division, new buds will sprout from the base of the pseudobulb cluster and then form full plants.
Cutting select unflowered, fully grown pseudobulbs, cut them from the rootstock as cuttings, cut into 1 section every 2-3 nodes, let them sit for a few days until the cut heals, then insert them into moss or coarse sand, or wrap the base of the cutting with water moss, leaving half exposed, keep moist, and under conditions of 22°C-30°C, they can root and form seedlings 40-60 days after insertion, and can bloom after 2 years of cultivation. During the cutting process, using flowering pseudobulbs and weak pseudobulbs as cuttings results in a low germination and survival rate.
High Node Dendrobium can be propagated using the high node transplantation method. Sometimes Dendrobium does not bloom but grows high nodes. When the high node has 4-5 leaves and 3-4 white roots 1-2cm long below, the small plant can be cut off with a sterilized scissor, 2-3 plants as a clump, wrapped in water moss at the root and planted in a 10cm plastic pot, which will become commercial plants after 2-3 years of cultivation.
Cultivation and Maintenance
Young seedling stage from the tissue culture seedling stage to the young seedling stage, usually with 1-2 pseudobulbs and a plant height of less than 10cm, the cultivation time in tropical regions is from October of the previous year to April of the next year. Young seedlings can be cultivated using coconut shell wrapping or using loose and breathable ceramsite mixed with pine bark, charcoal, etc., for potting. When cultivating individually, the diameter of the cultivation container should not be too large, generally 15-20cm is more suitable, which is conducive to the ventilation of Dendrobium roots and suitable for the growth of succulent roots, whereas dense cultivation substrates often lead to excessive moisture and are prone to root rot.
Young seedlings should be fertilized 3-4 times a month at a concentration of 0.1% (pH 6.5-7.0), with foliar spray and combined root irrigation. The fertilizer mainly consists of a balanced NPK fertilizer (N:P2O5:K2O=20:20:20), and after 2-3 months of planting, when the young seedlings have recovered their growth, an additional high potassium fertilizer (N:P2O5:K2O=15:10:30) should be applied once a month.
Water management should be sprayed every 1-2 days depending on the weather, and no spraying is needed on the day of fertilization. The temperature should be kept around 30°C to promote rapid growth, and measures should be taken in winter to keep the temperature above 15°C to prevent cold damage. If the light is too strong, a 50% shade net can be used for shading, and the light intensity should be controlled at around 40000-60000lx.
Middle seedling stage middle-stage Dendrobium usually has 3-4 pseudobulbs and a height of about 15cm, with the growing season in tropical regions roughly from May to June. Fertilize 3-4 times a month, increasing the concentration to 0.02% (pH 6.5-7.0). The fertilizer mainly consists of a balanced NPK fertilizer (N:P2O5:K2O=20:20:20), with one application of high potassium fertilizer (N:P2O5:K2O=15:10:30) per month. Or, a slow-release fertilizer (N:P2O5:K2O=16:8:12) can be used, with a nutrient supply lasting about 4 months, and usually only clear water is poured with an appropriate supplement of high phosphorus fertilizer. Water management involves spraying twice a day in the morning and evening. The light intensity should be controlled at around 60000-80000lx.
Large seedling stage large-stage Dendrobium usually has more than 4 pseudobulbs and a height of over 20cm, with the growing season in tropical regions roughly from July to August. Fertilize 4 times a month at a concentration of 0.02% (pH 6.5-7.0). The fertilizer mainly consists of a balanced NPK fertilizer (N:P2O5:K2O=20:20:20), with one application of high phosphorus fertilizer (N:P2O5:K2O=9:45:15) per month to promote the maturation of the pseudobulbs. Water management involves spraying twice a day in the morning and evening. The light intensity should be controlled at around 60000-80000lx.
Flowering
When the Dendrobium plant has more than 3-4 pseudobulbs and a height of at least 20cm, the newly sprouted pseudobulbs are usually flowering stems. Flowering stems grow rapidly at an optimal temperature of 28°C-35°C and a light intensity of 60000-80000lx, reaching a height of over 30cm in 30-45 days and producing flower buds in September to October, with the inflorescence developing for about 30 days before flowering. After the initial flowering, Dendrobium can be moved to an indoor or shaded area, and the flowering period can last for 30-60 days.
The above is the complete content on how to cultivate Dendrobium in autumn and the maintenance points of potted Dendrobium orchids, which green plant enthusiasts can refer to.