Saturday, August 17, 2013

Sphagnum Moss for Orchids

When I started growing orchids I used a fir bark based mix for everything. It was easy to use and worked well. When I got the greenhouse, I started using rocks because I needed the drainage. Now I am using sphagnum moss more and more for Cattleyas and Dendrobiums. I just got another 240-litre bale.

Sphagnum moss in small packages is kind of expensive. That is why I got my first bale. Sphagnum moss keeps well and I figured I had a lifetime supply. Now I am on my fourth bale.

What makes it work for orchids that want to be dry between watering are three things. First, use a clay pot. It gets the moisture level down pretty quickly. Second, let it get very dry between watering, to a point that the surface is hard. Third, pay attention to the rule of thumb number 2. "Whatever you do, do it before noon".


  1. i have started using sphagnum a lot more lately. i had a kingianum keiki that i was going to give to a friend so i put in in a pot with an inch of sphag on bottom just to keep it moist til i saw her and didn't look at it for a while. wow it went crazy in the sphag. i haven't gotten brave enough to try with catts yet tho

  2. I have also started repotting using sphagnum moss. I use clay orchid pots - the ones with holes on the sides as well as on the bottom. These are available at Home Depot. When I pot, I cover all the holes in the bottom and sides with wet sphagnum pressed in firmly from the inside, then use fir bark for the rest. I hang the pots in my lath house with wire hangers to ensure free air-flow around the entire pot and plant. The catts seem to absolutely love it. Great growth this year.

  3. I have begun to use sphagnum moss for orchids that I have failed to keep healthy. I have put moss in clay, plastic, and little plastic cups 4oz size with moss. I use Superthrive on them. Is this a good idea? I have had some success but keep going backwards in my care and they end up drying, then I have to start over.

    Thank you, I found this site by accident and love reading about your success with backbulbs. I seem to have too many BB's. Today I cut a section off my Catt. Deanna Sanders and tonight I read on your tips, Do it before noon. So I guess I will let this chunk set until morning.

    1. For Catts and Dens, plastic holds too much moisture in the sphagnum. For backbulbs, watering depends on the roots just like a plant with a lead.

      The "do it before noon" is not as important in the growing season, but the plant should be dry by the time the temperature drops at night. Now when it is still summer, don't worry too much.