How to Repot and Rebloom an Orchid

The phalaenopsis orchid is purchased more often than almost any other houseplant in Britain, and it dies in far greater numbers than it should. The typical trajectory is this: bought in bloom in a supermarket, enjoyed for several weeks, then placed on a windowsill where it gradually loses its flowers over the following months and eventually sits, apparently healthy but entirely flowerless, until it is disposed of. This trajectory is entirely avoidable. The phalaenopsis orchid is not a disposable plant. It is a perennial that can rebloom reliably for decades if treated correctly.

Understanding how the orchid grows

Phalaenopsis orchids are epiphytes: in nature, they grow on the surfaces of trees, their roots exposed to air, absorbing moisture and nutrients from rain and decomposing organic matter. This origin explains why they resent most conventional houseplant care. They do not want to sit in soil, and they actively dislike having their roots waterlogged. The correct growing medium is a coarse bark-based mix that allows air to circulate around the roots. The transparent plastic pots in which most supermarket orchids are sold allow you to monitor the moisture level of the roots: green or silver-green roots are healthy; brown or mushy roots indicate rot.

Watering: the most common mistake

More orchids die from overwatering than from any other cause. The correct watering regime is simple: water thoroughly once a week by placing the pot in a shallow container of water for fifteen minutes, allowing the bark to absorb moisture fully, then removing and allowing to drain completely. Never allow the pot to sit in standing water: this is the single most common orchid-killing practice. In winter, reduce watering to once every ten days.

“An orchid that has stopped flowering has not given up. It is waiting for the temperature drop that will signal the start of its new flowering cycle. Give it that signal and it will respond.”

How to trigger reblooming

The key to triggering a new flower spike in a phalaenopsis orchid is a temperature differential between day and night. In nature, nights cool significantly compared to days, and this temperature drop is the signal that triggers flowering. In a centrally heated British home, temperatures are artificially stable, and the orchid receives no seasonal signal. The solution is to move the orchid to a cooler spot at night in autumn: near a window where temperatures drop to 16 to 18 degrees Celsius overnight. After three to four weeks of this treatment, a new flower spike should begin to emerge from the base of the leaves.

When and how to repot

Repot a phalaenopsis orchid when the roots have filled the pot completely, when the bark medium has decomposed to a fine, wet mulch, or when the plant has been in the same pot for two or more years. Spring, after the flowering period, is the best time. Remove the plant from its pot, gently shake off the old bark, and trim any dead or rotten roots with clean scissors. Repot into a pot one size larger than the previous one, using fresh bark-based orchid compost. Water lightly after repotting and wait two weeks before resuming normal feeding.