Repotting Orchids, Part 1: Phalaenopsis

Phalaenopsis, or moth orchid, is called the “gateway orchid” for beginning collectors: it requires very little care, and yields great rewards with blooms that last up to three months! Early success with a moth orchid leads growers to try other species and, finally, to orchid addiction. But how do you ensure early success?

As a new orchid grower, I was not aware you had to repot your orchids shortly after purchasing them because they are often packed in sphagnum moss, which provides too much moisture for the plant. I was also not aware that you should repot your orchids every one to two years to maintain healthy plants.

Anne Nies, a master’s degree candidate in the Garden and Northwestern University’s Plant Biology and Conservation program, is an expert in all things orchids, both native and tropical.  She took some time this past fall to show me (and you) how to repot our orchids to maintain a healthy growing environment.

Our first video details step-by-step instructions for repotting a Phalaeanopsis orchid. Stay tuned for part two next week, when Anne reviews the different approach used in repotting a Paphiopedilum orchid, which has different watering and culture needs.

Video note: soaking the orchid you are repotting in virucide should not be a replacement for watering. After soaking the plant in the solution, repot and water well. Make sure your container has good drainage holes, is planted in a well-draining bark media (not moss), and the plant is never allowed to sit in a saucer of water.

Julie McCaffrey
Media Relations Manager
December 23, 2013


Can you please tell me again what was the audition you used to soak the roots before repotting .
Thank you

Could you please tell me the name of the solution again and the three things you mix for repotting thank you

Its called virucide

The solution is virucide. The potting mix used in the video is made up of bark, perlite, and sphagnum moss.

My orchid has 9 buds on it but they are not opening. What do I need to do?

is it o.k. to use hydrogen peroxide/sodium bicarbonate... ...?

The leaves on my phaelonopsis are beginning to turn yellow. What should I do? Would repotting help?

I assume you are asking this to control disease symptoms on an orchid. I both personally use and also know of a fair number of reputable sources that use hydrogen peroxide for orchid disease control. Hydrogen peroxide only works as a contact control, and so won’t kill systemic diseases such as orchid viruses. But it can help control various bacterial and fungal diseases, such as Erwinia bacterial leaf spot. There are commercial hydrogen peroxide products that can be diluted and used, but the 3% solution from the drug store works as well. Simply add the latter full strength to a spray bottle. When I find an infected leaf I first trim out the diseased parts with a sterile blade then spray both leaf surfaces thoroughly with the hydrogen peroxide. Reapply weekly until the symptoms are no longer spreading.

I’ve read of baking soda (sodium bicarbonate) being used but have no personal experience with it.

Good luck!

If only the bottom leaves on your Phalaenopsis are turning yellow, then you likely have nothing to be concerned about. The leaves of your moth orchid will persist for several years then eventually senesce and drop off. The bottom most leaves will turn yellow before they fall off as the plant is moving nutrients out of them. This often occurs in late winter into spring as the plant initiates new leaves and flower stems. However, if your entire plant has turned yellow this can indicate it is either receiving too much light, or else it has been kept too wet and the roots have died.

Can I make a virucide at home? If so, what are the ingredients and ratios?