Orchid Articles: Grow Your Own...   

By Col in Silver

 

Once you have grown your orchids successfully for a year or two, you may begin to think about propagation.

 

Orchids are increased by division, in one form or another, or by seed. The latter is, I feel, beyond the scope of this series of articles, which are intended for the beginner. Division of plants may be effected by cutting the plant, by removing the small plants (which are called `Keikis') that sometimes appear on old pseudobulbs or by a laboratory technique called `Meristem Culture'.

Plants which have pseudobulbs such as Cattleyas, Oncidiums or Cymbidiums may simply be severed through the rhizome, giving you two or more pieces. Never divide plants into single pseudobulbs or growths. The 'backbulbs' normally have a 'dormant eye' and will soon develop new roots and signs of new growth. Divisions may be potted separately.

Some orchids, principally Dendrobiums and Epidendrums produce new plants at the top or on sides of their stems. When their roots are about 50 mm long, these plantlets may be detached and potted into fine bark, polystyrene mix, rockwool mix, or sphagnum moss. Dendrobiums can also be propagated by laying old pseudobulbs horizontally on river sand. If conditions are good, plantlets appear along the length of the pseudobulbs. Some Phalaenopsis will produce small plantlets on the end of flower spikes, treat these as you would Dendrobiums.

Paphiopedilums and Masdevallias should be divided only when they are sufficiently large with multiple growths. Take special care when dividing Paphiopedilums as quite often roots are not produced on new growths until they are mature. When potting, ensure that all growths are ± 12 mm below the potting mix to allow new roots to grow into the medium.

When dividing plants always ensure that cutting instruments are sterilized after use on each plant.