Dividing and Propagating Orchids

While dividing orchids is not always necessary for plant health, many orchid varieties can expand to the point where a normal container and soil allotment is not enough to ensure its survival. Most hobbyists prefer to divide expansive orchid plants, both for the plant’s own health and to propagate more plants for their collection.

For newcomers to orchid care, however, the thought of dividing an orchid can seem like the sure method for killing their plant. A series of simple steps can help ensure the safe and successful division of most common orchid varieties.

Classifying Orchids for Division

The method of dividing an orchid is based on its expansion classification, or the method by which the orchid increases its size. Monopodial orchids grow taller as new growth forms at the stem’s tip; leaves grow in pairs in an alternating pattern, placed on opposite sides of the stem. The orchids may be short, yet still belong to this category.

Sympodial growth classification encompasses plants whose height growth ceases after the first season; future growth arises from the base of the plant, growing laterally or vertically from its beginning point. Pseudobulbs are prevalent in this type, with blooms emerging from the tip or base of new growth or from older growth’s buds.

Division of Sympodial Orchids

This type of orchid is often divided like a bulb plant, such as an iris. A clean, sharp blade cuts through the rhizome to create three to five pseudobulbs or stems with each cut. The roots are then pulled apart according to which section their base is attached, then the separate sections are replanted.

Old stems or bulbs from the rear of the plant can also be salvaged for replanting, since division from the younger, more active plants may stimulate them to return to life. Place them in empty pots; if signs of green life appear, then transfer them to soil. Methods for each type of sympodial orchids may vary, since some bulbs can be broken apart by hand; some stems can be cut into sections and moss-planted to form roots.

Division of Monopodial Orchids

Side shoots on monopodial orchids can be removed and repotted as soon as individual roots form. Tall plants may produce aerial or free-floating roots from new growth; the upper portion of the plant can be cut free below some of its trailing roots, then potted to produce a new plant.

If plantlets or keikis form on flower spikes, they can cut or broken off when their floating roots are an inch or more long; plant them in a closed, moist environment by covering the cutting and its pot with a plastic bag to encourage strong and rapid growth.

Final Tips on Dividing Orchids

Other forms of division are not for inexperienced growers, including meristem cultures and seedling orchid plants. The basic methods of dividing and propagating orchids, however, can be mastered with a little, patience, and practice by new orchid growers or long-time owners with a desire to increase their plant numbers.

Resources:

Dunmire, John R. Orchids (Sunset Edition). Sunset Books, Inc., 1998.