Rescue Phal Repot!
 

Hi all!

I thought to post a rescue Phal I just bought at the pharmacy for 10.99 Canadian (8.70 USD). I saw the beautiful orange flowers, and it’s sad brown crispy root and its dark green leaves. I couldn’t leave it.

When I went to repot it, I found mostly healthy green roots! I cut away its brown root and repotted it into a orchid bark/pearlite mix with some sphagnum moss. I also gave it a spray with hydrogen peroxide.

I have some hopes for this one, with the right conditions it should turn around.

What does everyone else think?

Photo description:
Photo 1 and 2: pictures of the repot
Photo 3 and 4: picture of the roots with the moss removed
Photo 5: A picture of the roots really tightly bounded in the moss

All looks good except for the peroxide. Don't use it.. especially on roots. It damages roots, and can seriously set the plant back. With a healthy environment - your new potting mix - the roots should not need any treatment at all. One note.. the new mix will dry out much faster than the original sphagnum. So you will need to water more often. You can get a feel for how fast the plant dries out by weighing it right after watering (postal scale or kitchen scale), and then in subsequent days. When the reduction in weight slows down, time to water again. The new mix will give you lots of air around the roots - exactly what they need.

RE: Roberta

Oh that’s so interesting about the peroxide! I have done that with some of my new plants as a quarantine measure to stop them from potentially giving any issues to the rest of my plants. I didnt know that it could cause issues to their roots. Is this orchid specific because of their delicate roots?

Peroxide has been a huge trend lately for plants. I have seen a lot of bad plant advice. I generally thought peroxide is a good one... I must have been wrong.

I also have been following this trend with plants that spraying some peroxide can be good to promote growth. I did this for my pothos propagations and they seam to like it... But on the general whole, I will stop doing this.

I love the measuring trick! I do know that barks do dry out much faster than the moss. I generally do a good job at watering my orchids in bark, but I love the idea of measuring out the weights. I will start a data sheet for them tomorrow!

Thank you Roberta.

I would have to suspect that peroxide on roots of any plant is destructive... if you put it on a wound with jagged edges, it fizzes... it's oxidizing the rough surface. On a root, with tiny hairs, lots of surface area, it's going to do the same thing. I know that it is recommended in lots of YouTube videos... but thinking about its actual course of action, not really what you want to do to a root - where the large surface area is what it uses to efficiently absorb water. In the case of orchids, those hairs also have the task of grabbing onto surfaces like trees in nature (or attaching to a mount or to the medium in the pot.) So they're really important.

A healthy environment for roots is one with lots of humid air. That's what we achieve with bark or other medium. When the medium breaks down, so that the air spaces are gone, roots rot. So the solution to root rot is to maintain an airy environment that lets the roots dry out a bit.

That makes a lot of sense. To be fair, the actual roots were not directly sprayed, but rather were given a light mist of the peroxide. I definitely didn’t see any fizzing or bubbling or really any reaction. But I agree.

I like your explanation of the healthy air within the medium promoting healthy roots. That makes a lot of sense, especially when it comes to bark.

Thank you :)

Where is this advice about hydrogen peroxide being bad for roots even coming from? It's frequently repeated in the forums, and understand the arguements against it, but is it actually based on anything other than assumption? I understand that it's damaging on open flesh wounds, but it's quite a leap to assume that it functions the same way on plant tissues. Out of curiosity I searched for some scientific literature about exogenous H2O2 application on plant roots, and at low concentrations (still more concetrated than the typical 3% we buy) it appears to to stimulate root/plant growth (on the studies plant species).... This is something I'd like to dig into deeper, and review the existing literature, unless it really is a known/tested fact that it's bad for orchid roots. And the next question would be how did it even become a thing to use H202 on roots. Up until a couple years ago, I never heard of such a thing.

Hi Camille,

I actually heard the same thing. I did a bit of research myself and read that the extra oxygen molecule could stimulate growth. I looked into it because when I listened to the plant trends about the benefits of peroxide, I had a hard time believing it myself. After reading up about it a bit, I decided to try it. I have noticed that my propagations seem to respond well to it. It’s always in very light amounts. Its diluted to 3%, which is the most common one to way to buy peroxide, at least in Canada.

I am not entirely sure of the science behind the root growth or benefits of the peroxide with plants, but the pest control make the most sense to me. That is why I do occasionally use it if I am worried about pests or disease.

I did some research awhile back and if I recall correctly concentrations in excess of ~0.3% or there about damaged tissue. It’s indiscriminant: it will kill fungi, bacteria, and healthy tissue. Plants naturally produce hydrogen peroxide to fight infections but nowhere near 3%. It’s no longer recommended for wound care either because it damages tissue and actually slows healing. Any oxygen produced is also going to be so transitory as to be negligible.

---------- Post added at 09:27 PM ---------- Previous post was at 07:54 PM ----------

This article goes through a lot of the supposed benefits of using hydrogen peroxide: Should Hydrogen Peroxide Be Used in the Garden? - Garden Myths

RE: aliceinwl

That makes a lot of sense! There is always science that makes a claim, and within time it is debunked.

It also makes the most sense that it kills everything indiscriminately. I don’t regret giving this particular orchid a light spray because I wasn’t sure what kind of suffering the pharmacy put it through prior. It looks like a fairly young orchid, with young blooms, but you could tell that it would decline quick in the same conditions. So a light spray to disinfect it wasn’t a very bad choice lol. I didn’t want to risk it passing anything to my healthy orchids.

I appreciate the discussion we had on peroxide with plants!

I don’t use hydrogen peroxide as a general spray (I have surgically applied it to the crowns of plants with crown rot issues). To make it “safe” for general application, the recommendation is to add 1 or 1/2 teaspoon of 3% hydrogen peroxide to a cup of water before spraying on plants. I can’t vouch for this actually being safe/effective though.