This top-heavy, wobbly orchid with lots of bare stem should have been repotted years ago. Photo: F. Hardouin
Question: Over the years, the lower leaves of my orchid have fallen off and others have grown. However, it now has a tall, unstable stem that needs staking and any charm it once had has been lost. Should I repot it? Should I prune it? I have no idea what to do! Help!
Answer: Your orchid is a phalaenopsis or moth orchid (Phalaenopsis cv). Its growth is quite normal for a plant of its genus and in fact, it would grow to look a lot like yours does—a lengthening stem bare of lower leaves but abundantly covered in aerial roots with green leaves only on the top—in the wild. That’s because it’s a monopodial orchid and grows upward from a single growing point. And because old leaves—the lowest ones—simply die and fall off over time.
Usually, however, cultivated phalaenopsis are not allowed to grow in such an ungainly fashion, but are repotted regularly before the stem becomes too bare.
Therefore, you should have repotted your phalaenopsis every 3 years or so, planting it lower in its new pot each time by surrounding the bottom part of the stem with orchid potting mix (a special “soil” developed especially for orchids). Thus, it would have remained about the same size, with a very short and, in fact, almost invisible stem at the base.
Special Cases Require Special Treatment
But your orchid is “too far gone” for a simple repotting. It’s hard to imagine a pot tall enough and narrow enough to cover all that bare stem! So, you’ll have to try something a bit more radical to recuperate your plant. You’ll have to cut off the top and reroot it to get it back on track.
So, using sterilized pruning shears (wipe the blades with rubbing alcohol), cut the stem about 3 inches (7.5 cm) below the lowest healthy leaf. Spray the resulting cutting with a 3% hydrogen peroxide solution to sterilize the wound.
Using a clean pot of about the same dimensions as the original pot, add orchid potting mix to about 1/3 of its height. Center the stem in the pot and fill all around with mix, up to the height of the last intact leaf, so that no bare stem will be visible after you finish. If there are aerial roots that will be buried as you do this, that’s not a problem. Tamp lightly.
Most likely the cutting will be held quite solidly by the added mix. If not, it may be necessary to insert a small stake into the mix and attach the orchid to it with a twist tie. You don’t want the cutting to be able to move, as that will hinder rooting.
Now, water and, later, keep the soil slightly moist while new roots form, a process which will take several months. Since there will be few active roots to absorb the water, it’s possible you’ll only have to water every few weeks at first.
(If you keep watering the lower part of the original plant, a small orchid [keiki] may well form. If so, when it’s large enough, remove it and pot it up separately).
Over time, new roots will form on the cutting that will cling to the potting mix. And it won’t be a cutting anymore, but a fully independent young orchid plant that will resume normal growth and begin to bloom, probably within a year.
But next time, don’t forget to repot your orchid about every 3 years! After all, restarting an orchid from cuttings is far more stressful and risky for the plant than simply repotting it!