Sawdust mix for Catasetinae

[euplusia]

By request I suggest my potting mix used for Catasetinae. It consists of 60 percent by volume of fine sawdust from a carpenter (probably mainly spruce) and 40 percent by volume of clay pellets (Seramis R).
I add some Dolomite stone powder and use plastic pots.
Potting season is end of March and April. The results are better than potting in bark mix.

[katrina]

My husband does a lot of wood working...I am definitely going to try this mix w/some of my Ctsm at the next repot.

Approximately, how much dolomite do you use?



Thanks so much for taking the time to post this.

[isurus79]

Its interesting to see the different types of media this group of orchids can be grown in. I understand that many types of Catasetinae (especially Mormodes) naturally grow on rotting wood, this mix makes sense.

How long does it last before you repot?

[veekay]

Originally Posted by euplusia

By request I suggest my potting mix used for Catasetinae. It consists of 60 percent by volume of fine sawdust from a carpenter (probably mainly spruce) and 40 percent by volume of clay pellets (Seramis R).
I add some Dolomite stone powder and use plastic pots.
Potting season is end of March and April. The results are better than potting in bark mix.

HI,
i have grown with coco boss,pearlite(50:50%) and a variety gravel( Terrazzo chips) with good results,but the problem is if you are growing under Saran netting alone medium has to be changed every18 months.
veekay

[kindrag23]

Would wood shavings work in the same aspect? I do not have readily available sawdust.

---------- Post added at 10:16 AM ---------- Previous post was at 10:15 AM ----------

All of mine are in sphagnum moss and some lava rock thrown in to help with stability and are growing well thus far.

[euplusia]

One heaped teaspoonful of Dolomite is sufficient for 10 liters of potting mix.
Annual repotting is best, at least repotting must be done every other year.
The man who gave me this tip said that by coincidence he had laid Cattleya bulbs upon sawdust and was surprised to see how plentiful they started rooting.
Nevertheless my approach were difficulties in growing Mormodes. They only live on decaying wood. Bark mix was not successful and old rotten pine bark was even worse. I felt I should macerate the wood structure to make it better available for strong growing plants.
This spring I potted 3 Mormodes in a mix of betula sawdust instead of spruce. So far with good results. I will post some pictures soon.
Your suggestions and ideas are always highly appreciated.

---------- Post added at 10:44 PM ---------- Previous post was at 10:42 PM ----------

[QUOTE=kindrag23;632469]Would wood shavings work in the same aspect? I do not have readily available sawdust.[COLOR="Silver"]

Give it a try.

[TOMMYMIAMI]

This is very interesting, I have actually one Mormodes plant, it is potted only in medium bark from seller, so I will wait till spring and use this mix! Will try for some catasetums also:-) Many thanks for sharing.

[Bud]

I am going to try your Catasetinae mix.
After I read this thread I walked 5 blocks to the NYC department of sanitation where they have trucks that mulch wood from pruning trees on sidewalks and parks and I was able to get sawdust at the bottom of the truck bin that is from freshly cut trees that still have moisture content in varying size flakes from fine to medium composed of ash tree, oak, maple, beech and yellow birch.
The cheapest clay pellets I got were the cat litter ‘zooland’ brand that is perfect to go with my sawdust mix. I got from Ebay a coarse dolomite sandy particles that cost $3.00 half a gallon ziplock bag. When I get new growths from my plants this spring, I am all set.

[Andrew]

Euplusia,
How long have you been using this mix? I assume you're using raw sawdust. Have you run into any issues with nitrogen deficiency or do you use a high N fertiliser to compensate for any nitrogen drawdown?

[euplusia]

I have been using this mix over three full growth cycles now, for about 300 plants. So I can say it is tested.
I did not notice a nitrogen deficiency. I mostly use a balanced fertilizer, because I was afraid of rot when giving too high nitrogen doses. The sawdust does not decompose within the first year. And then I prefer to repot.
Pet Shops are often a good source for clean unexpensive potting media. Bird grit is an example.