How to Repot Orchids
Learn how to repot a moth orchid.
The window in my office sports a collection of five orchids, which open blooms in shades of pink, white and gold with brown speckles. My husband is the orchid expert; I’m the one who kills them, usually by overwatering.
This summer busy schedules landed orchid care on my to-do list. True to form, I nearly killed my husband’s two most treasured plants through—you guessed it—overwatering. Wilted, floppy, wrinkled leaves, combined with moist growing mix, are sure signs of overwatering. The orchids also had many roots that were brown, another sign of impending death.
But orchids are tough, and my husband assured me we could save the plants by repotting. Here’s what we did to revive our orchids.
Gather Your Tools
When repotting orchids, the tool list is short and sweet (clockwise from lower left): pine bark, unmilled sphagnum moss, sharp pruners and a lighter (to sterilize pruning blades). Choose pruners with narrow blades that can easily reach into the orchid root system. Scissors also work well.
In pots, orchids usually grow in a chunky pine bark blend. This is what you often get when you buy a bag of orchid mix. The bark chunks form air spaces in the pot that become humid after watering—the ideal growing environment for high humidity-loving orchids. We add unmilled sphagnum peat moss to the pine bark because it retains moisture longer than bark and boosts humidity around roots.
The last tool to grab for repotting orchids is a pot. Orchid pots feature drainage holes and/or slits on the bottom and sides. The slits increase air flow to roots. Moth orchids (Phalaenopsis) like ours have green roots that photosynthesize, so they really thrive in clear orchid pots. As a habitual overwaterer, I prefer clear pots because I can see how moist the potting mix is and how roots are doing. We didn’t have an orchid pot on hand the day we finally had time to repot this orchid, so we used a plastic pot.
Remove the Orchid From its Pot
Upend the orchid over a pan, cradling the plant as it falls from the pot. Gently remove pieces of pine bark until the root system is free of any growing mix.
Clip Dead Roots
Sterilize pruner blades by passing them through the lighter flame. Snip dead or dying roots, placing cuts as close as possible to the main growing stem. Healthy orchid roots are green to whitish-green. Problem roots are brown, black or white. The texture may be mushy (underground anchoring roots) or crispy (aerial roots).
We also cut off the bottom part of the main stem that was soft and clearly dead. Here’s what the orchid look like after root pruning.
Prepare Potting Mix
We create a custom orchid growing mix using one part unmilled sphagnum moss to two parts pine bark. Normally it’s a good idea to soak the moss prior to use, but since I had overwatered these orchids, we used dry moss to avoid surrounding the remaining roots with too much moisture. Blend the bark and moss together.
Repot the Orchid
Position the orchid so you have a few roots extending down into the pot. After root pruning, we had no roots growing in that direction—I had killed them all. Gently reposition a few aerial roots to work them into the pot. Do this before adding any potting mix so you can easily work the roots into the pot.
Make sure the orchid sits at the same level in the potting mix that it did before. As you hold the orchid in place, begin to add the potting mix. Try to work with larger bark chunks toward the bottom of the pot; use smaller ones toward the top.
We don’t use the smallest bark chunks because one reason orchids need repotting (aside from overwatering) is that the potting mix breaks down over time. Using larger bark chunks helps ensure your mix won’t decompose too quickly. We also strategically placed sphagnum moss near one tiny new root so that it would encounter a moist spot as it grew.
After repotting, the orchid should sit snugly in the pot, anchored by the roots in the potting mix. Water thoroughly until water runs out the bottom of the pot, taking care to moisten the sphagnum moss. After repotting, the leaves are still wrinkled and wilted.
One month after repotting, the orchid leaves were still wrinkled, and the new little root hadn’t really grown. At the two-month mark, the same four leaves are present but now strong and healthy, with the new root penetrating the potting mix. Three months after repotting, the new root has burrowed into the potting mix, and three additional new roots are sprouting from the main stem. Seeing a new leaf will be our next milestone. I should also add that I am no longer the orchid caregiver. I think I can do it right this time, but my husband isn’t willing to turn me loose just yet. I can’t say I blame him.