Pots, clay vs plastic for Phalaenopsis

[deharti]

I live in Boise, Idaho. I am having trouble keeping the right moisture level for my Phalaenopsis. They are in house so the air is dry. They are currently in a coconut husk, sphagnum moss medium in an 8 inch plastic orchid pot.
The roots in the medium are rotting. Should I change pots, medium or both? We have low humidity here in the high desert country but it seems that a once a week watering is too much with the moss?

They are ready to be re-potted.

[cbuchman]

An 8" pot would be for a very big Phal. Use the smallest pot possible that the roots will fit into. This will help them dry out after too. If your roots are rotting, then the medium is too wet.

Phals roots are capable of photosynthesis is the pot allows light to reach the roots. So consider a clear plastic pot. The clear plastic also allows you to see the roots and easily check on their health. Though, if you need them to dry more quickly, a clay pot is can be helpful.

Also look at your CHC/moss and make sure that it is "airy". Remember that Phals are epiphytes so they want air around their roots. I've been successful with 1/2 large bark and 1/2 sphag as my phal.medium.

So yes change pot and medium ASAP. Clean off any rotten (brown/soft/mushy) roots with a sterile instrument before re-potting. Hopefully there will be some roots left to help the phal get settled into its new pot.

[DelawareJim]

I echo what Carrie said. I have all my Phals except one that's mounted in clear plastic Aircone pots. You'd be surprised how mulch moisture you can see clinging to the sides down in the pot even though the surface has been dry for days. My mix is half 3/4 to 1 inch fir bark and half long-fibre sphagnum. My biggest pot is a 4 inch pot. I currently have several bellinas and violacae blooming in 2 and 2-1/2 inch pots.

Cheers.
Jim

[tucker85]

I agree with both Carrie and Jim. I've found that one of the most important things is to use the smallest pot that the roots will comfortably fit in, like Carrie said. Sometimes that means a pot that looks too small for the plant. I like clear plastic pots with slits in the sides. I can see the roots and the mix. The pot can be placed inside a decorative pot if you don't like the way it looks. I also agree that mixing the sphagnum with something like bark would help also. I have more luck with phals if they're in a mix that will dry completely in about 4 or 5 days. That may mean watering more often but also means less problems with root rot.

[deharti]

I appreciate all the good information. Most of my Phals are large older plants with 16 to 20 leaves and lots of air roots. I will repot in as small a pot as I can to help with the drying and air circulation.
Would you choose the Aircone pots over say a white plastic orchid pot? Question, when I have purchased small starts in the clear pots I have noticed that dark green moss soon covers the inside in my growing conditions. Is that a problem or a natural process? Ivy

[DelawareJim]

I personally would choose the Aircone pot because it's clear, and it lets the core dry more quickly. I've often thought of putting a small seedling pot or a net pot flipped upside down in the bottom of a bigger pot and then plant on top of it. You'd basically have a hollow dome of medium in the pot that the plant is growing in. Like we do with sphagnum moss mounds for Neofinetias.

Cheers.
Jim

[WhiteRabbit]

The green stuff growing in your clear pots is algae. Doesn't harm the plants.

I use either a small over-turned net pot in the center, or some styrofoam in the center of the root mass.

[deharti]

I like the idea of air circulation in the center with either the Aircone or upside down net pot. I think it would help my situation a lot. The Phals are not growing as well as they used to. I think that root loss is a big part of the problem as well as needing more light. My windows are shaded longer now that our trees are bigger.

[DelawareJim]

I don't think the shade is affecting the plants top growth as much as it is reducing the evapouration rate in the pot causing the rot. Go to Google images and google "Phalaenopsis in situ" (in the wild). You should see almost all the pictures show the plants growing in total shade with completely exposed root systems. Ideally, we would grow our Phals mounted on cork, on a north facing wall, and watered/fertilized daily at roughly 25 ppm N.

Cheers.
Jim

[james mickelso]

I'll ask another question. Why do you think your phals need high humidity? It seems you are trying to raise the humidity by overwatering. Why? Have you tried watering less and then had trouble with your leaves and roots dehydrating? Shriveling? Or did you assume because phals grow in humid swamps in the wild they must must need high humidity? The coconut husk will stay wet down in the center of the pot far longer than necessary so why the moss? When an orchid is watered, it is the roots we are trying to water and not the media. Phals grow mounted on cork plaques, media-less clay pots, and I've seen them dangling in the air on a string and doing just fine. I suggest you water less before changing anything else and see what that produces. Phals don't need high humidity to grow well. Their roots need to be watered when they get dry. If you use a coarser media in which to grow them, then you can water them more without rotting their roots. In the wild they grow on the sides of trees, rocks, and branches. They don't grow any better there than in our homes. It is far less humid in our homes than in their natural settings yet they grow just fine. When you water, you water the roots. It's not necessary to water the media. I grow some of my phals in lava rock alone. Nothing else added and they grow just fine. Relative humidity has little to do with growing phals successfully. Wetting their roots when they are dry does. CHC is a fine media as long as it dries out between watering. I like the inverted pot or Styrofoam peanuts under the roots to help keep the inner volume of media from staying too wet. Both of these phals grow in lava rock. They are watered once a week if they are lucky. Oh, and one other item. You can grow orchids in pots that are only filled halfway to the rim. That way the media is not as deep. Or you can pot them in shallow saucers as long as you tie them into the saucers. You know. The shallow clay or plastic saucers that most folks put under their plants. That way the aerial roots can lay on a solid surface although this isn't really necessary.