Orchids are mostly epiphytic and attach themselves to the sides of trees or branches. They are adapted to adverse conditions and thrive well by accumulating water in leaves, stems and roots. When culturing at home, they are grown
in pots with loosely packed material that keeps the medium aerated and dry.
Propagation of orchids is done to produce more plants of the same variety or species. Six main techniques are used to propagate orchids, which are division, back bulbs, keiki, aerial cuttings, meristem or tissue culture and seed. Propagation through seed and meristem need laboratory conditions for sterility and are not commonly employed at home.
1. Division- It is the most commonly used method of propagating orchids. The plant is split into two or more parts with at least one new shoot and each produces a fully grown plant. Splitting a plant encourages the plant to produce more shoots of better quality and increased vigor. The plants selected for division should have at least three back bulbs and the divisions should have at least one new growth so that they can flower the following season.
2. Back Bulbs- This method uses old back pseudobulbs which are leafless, to produce a new plant. The plants grown using this method require 2-3 years to reach flowering size. The older back bulbs are removed and placed under ideal growing conditions to induce rooting. This can be done at the time of repotting. The method can be used to obtain identical plants of a selected species.
3. Keiki- Keiki is a small plant that grows on a node along the stem, in place of a new branch, as in case of Phalaenopsis orchids. Accumulation of growth hormones at the point can induce the production of a keiki. The method produces duplicates of the parent plant which can be left at place till they grow a root system and some leaves. Once they reach this state, they can be removed and potted to obtain flowering size plants within two years.
4. Aerial Cuttings- When certain plants like Dendrobium are subjected to stressful growing conditions; they develop small plants in place of flower buds. These can be removed from the parent plant and potted. The method produces plants identical to the parent plant.
5. Meristem or Tissue Culture- The highly scientific method of propagation is done under sterile laboratory conditions. In this method, a growing center of a new growth bud is grown by constant agitation in a nutrient rich solution. When the cell mass is large enough to be split into small sections, it is either grown into plants or the process is repeated to produce more tissue for further culture.
6. Seed- Orchid seeds are sustained during the early formative stages of its development under sterile laboratory conditions. Orchid seeds are like dust and require special techniques for sustenance. This method is not suitable while growing orchids at home.
