First Post and some history and questions

[eka]

My mother was always an orchid fanatic...well It has rubbed off! I have 5 dendrobiums and 2 paphs.
It is time to repot my dendrobiums and a friend gave me a bag of Better-Gro Phal potting mix.
Can I use this on the dens or do I need to get another mix
Also some of my dens have securley attached their roots to the wood block in their pots ( this is the original pots and soil from when I got them 10 month ago).

I will post pictures shorty.

[jerrymeola]

A lot of issues in a very simple question.

Repotting dens is not as necessary as other orchids. I try never to repot mine. Several are over 5 years in grossly overgrow pots.

That said we look at the condition of yours. You said it was in wood blocks. I have seen this in florida and hate it. These are large coconut husks and a bad growing medium for dens. I do not know how the commercial growers can get good results with it. I find that they do not do well for hobbists, so repotting is advised. Removing it will brake a lot of roots. The plant will adapt and grow new roots. Dens are very strong and grow in spite of us.

The phal mix is a large size mix based on the thick roots of a phal. Dens have many thin roots and will not hold itself well in the phal mix. Eventually it will adapt but a smaller mix will be easier. Also large bark will deteriorate and requires changing every two years for cattleyas and Phals.

Since you do not want to repot dens this often. a smaller mix with a high percentage of inorganic material is better. You will not be able to find this type of a mix in big box stores. You will need to go to an orchid nursery that grows dens and see if they will sell you some mix. Most growers have their own private mix they mix themselves.

I tried smoe 1/2 inch bark last year and the dens were slow to adapt to the mix, but did and are blooming. Now I try to use nothing over 1/4 inch bark mixed with inorganics. I get many dens grown in 1/2 bark from other commercial growers and it works well for them, but they have a tendancy to fall out of the pots. The mix does not hold the roots well. These are all personal observations and may not adapt well to your conditions.

[Cynthia, Prescott, AZ]

I think the mix will work OK. The important thing is to get the watering right. Most Dens will take a lot of water while they are growing, kind of like Phals, but when they have matured their growths, they should be allow to dry out between waterings, and, during winter, to be watered even less. Pot small, and the plant will help in the drying process so that it won't stay wet for long periods, which would be particularly bad for them. Cynthia, Prescott, AZ