Once I have repotted an orchid, my first tendency is to want to water it as I would any other household plant that I just planted. There are a few problems with watering an orchid right after a repot though, and in this article, I’m going to cover the pros and cons (mainly cons) of doing following that method.
In short, if you haven’t trimmed many roots, then you can water an orchid normally right after repotting it. If you had to trim a considerable number of roots, then it’s best if you do not water, waiting about a week to let the open cuts in the roots have ample time to heal.
How Orchid Roots Interact After a Repot
Water is an essential healing process for many plants, and orchids are no exception. Yet when you repot an orchid, you will be moving the roots around, detaching them from the sides of the pot, removing old and decayed potting media that has attached to the roots, and shaken that orchid up from its natural resting state.
Orchids do not like to be handled, touched, moved, much less repotted. They are made to attach themselves to trees and their roots will cling to tree bark where they plant to not be disturbed for the next few years.
The roots are made with a protective covering called velamen, which is (for the most part) a layer of old dead cells that allows water and humidity to be trapped inside the hollow canal, close to the main strand of the root. The velamen also creates a higher surface area for the roots to collect more nutrients and humidity when they have the chance.
Velamen also creates a solid barrier so that microorganisms such as bacteria, viruses and fungus don’t enter the roots.
When an orchid root dies or decays, it turns brown and mushy, offering no resistance when pressed between your fingers. The normal color of orchid roots should be gray to silver, and when watered, they should turn green. If there is no transition in color, then they have lost the chlorophyll that they have, which is a good indication that they are dead.
If you want to read more on how to know what orchid roots are healthy, then this article I wrote is a good place to start.
If the orchid roots are brown and even black, then they need to be cut. By cutting the velamen along with the stele (the actual root inside the velamen) you are creating an open door so that any microorganism that is near the roots may enter the plant. Of course, you have to cut the brown mushy root off, since it’s going to fall off anyway. But that door is now open and if you cut into healthy, green roots then the door is even wider.
If the roots have time to dry out, (by not watering immediately after a repot) they will by themselves seal off and close that door. It’s like a simple, tiny cut in our skin. In time, the skin will close that cut, creating new skin to close the barrier. In the meantime, we usually use a band-aid (or get stitches if it’s too deep). The orchid roots will seal off the open cells and close that door. Many people in the past have advocated using cinnamon for sealing the roots, but I don’t follow that method. In this article I explain why.
If you have had to do a considerable amount of cutting to remove old, decaying roots, then there are several open “wounds” in your orchid. If you have a very good root system and you didn’t have to cut any roots at all, just change out the potting media, then your orchid roots are intact.
How Water Affects the Roots
Let’s look at the first scenario: the open roots, almost all removes, with various cuts and not many good roots left. If you water your orchid in this step of the repot, then the roots will encounter a potential transmitter of bacteria. Lots of bacteria love to live in water, and they are transmitted by water droplets, mist, sprays, or even normal everyday watering.
By watering your orchid now, the chances that you are inducing a bacterium (I wish it were only a single noun) into that open “door” are enormous. You can diminish these chances by using a bactericide or fungicide, like Physan 20 (I have used this in the past, and you can check its price with my affiliate link on Amazon here). If you had a lot of bad roots to cut off, this is a very important step. If your roots were clean, then you don’t need to add excess chemicals to your orchids.
When Should You Use Water with An Orchid Repot
Please don’t think that I don’t use water at any phase during the orchid repot. I usually soak my orchids about 20 minutes before the entire process starts, but not after. This enables the roots to become more malleable and detach from the sides of the pot with more ease.
Once the orchid has been repoted, it’s best to wait a week before adding water. The orchid has already had a good soak with the 20 minutes beforehand, so it’s not going to be thirsty. The orchid will also focus its “dry” period to close the wound and seal by itself. If there is water anywhere near the roots, this will take more time to heal.
If you want to see how to repot, in this video below I show to repot a phalaenopsis, and in the second video, I show how to repot a Cattleya.
In summary, if your orchid was healthy and you had hardly any roots to cut, then congratulations. You have found that perfect balance between potting media and watering that your orchid loves. Keep up the good work and happy cultivating!
Don’t Stop Learning!
If you want to be included in a more information and get a 14-page fertilization guide, please sign up for my newsletter. I don’t spam, but send emails out bi-monthly with some curious topics of interest. If you want more information, click here to go to a specific page on this website where I explain it more in detail.
Also, if you are looking for an orchid journal to keep your notes specifically about orchid care, check out my 2 solutions for that on this page. If note-keeping isn’t your thing, then there is a free excel spreadsheet that you can download. Click here for more information on how to do that.
If you subscribe to my newsletter, I will send you a 14-page guide on the main tips of orchid fertilizer. It is downloadable and you can print it out on your computer. I designed the guide to double up as a coloring book, just to make it fun.