Den and Cattleya growing medium and water

Nov 19, 2007 Last reply: 18 years ago 4 Replies

Rate this thread:

Saved reading

BruceM 18 years ago

In your personal experience, what is a good medium for Dendrobiums and Cattleya's?

I have several new ones and a few older ones. The older ones were repotted in Better Gro Phalaeonopsis mix, a general purpose mix of Fir bark (about the size of a quaerter), hardwood charcoal, and a bark like peat material . BG had several other mixes for orchids, the big difference being no Peat in the others and one had a smaller bark chunks.

The cats seemt to do okay in it. They grow, new shoots, Several Kekei's , no flowers on any of the older ones (on one sI have had 1.5 years ). The dendroibiums appear to hate it. Most of them sit there, a couple have new growth. The Phal's go crazy in it. Looking at the books, it seems this should be a okay mix, but experience is always better.

Also, for watering: In general do Cat's and Den's like more water than Phal's? I water them on the same schedule, and some are oky, other show signs of needing more water such as wrinkled new growth, shriveled pseudobulbs, etc

Vote

Information here may be outdated?

K Barrett 18 years ago

Catts, I usually use a mix of small bark, perlite, lava rock and recently I've been adding osmunda fibers. I use small bark because I don't water as frequently as I should, so my medium is more closed than many people would do.

I don't have much luck with dendrobiums. It'll be interesting to see what people suggest.

I didn't know Catts would kekei....

K Barrett

Vote

tenman 18 years ago

I use both a 2/3 medium bark/ 1/3 #3spongerock mix and a 2/3 large CHC/

1/3 #4spongrock mix for mature catts in clay pots (small seedlings are in a finer mix in plastic). In the bark they are potted harder (tighter) and the CHC is used as a looser, more open mix (which creates issues of how to physically immobilize the plants). Both have worked ok, though in clay pots and my traditional dry conditions, the CHC has an edge. That said, it will depend a lot on your humidity levels and as well on temps and light as they affect metabolism and how much water the plants use. Dens I have in 'seedling mix' of 2/3fine bark and 1/3 #3spongerock in clay pots potted tightly.

A common misconception from which I myself once suffered concerns water levels. Orchids are water-loving plants when they are in their growth phase and with optimum conditions. Some such as vandas and catts don't want to sit in water constantly or be soggy but they do need copious amounts of water - the confusion is in thinking they don't need water because they don't want to stay wet. Ideally they should be wet, then dry and then wet right away again (during growth and in the daylight). The problem is that we stick them in pots and limit the air movement around the roots and packed medium and then we have problems we blame on water. So in culture, it's a balance you're looking for based on all those variables. This second glass of wine is making me loquacious.

Vote

BruceM 18 years ago

So I should have a glass of wine and share it with the Cat's ? Which cat, The Red Emperor or the Maine Coone? ;)

Thr Phal's seem to be a it less sensitive to drying out than the Cats and Dendrobiums (based on watching mine). would that be a correct general observation? Watching these over the last year, they seem to prefer it if I let the medium get dry just a 1-2 inches down and then water them. The phals seem to like it if I let the medium dry 3-4 inches down (4-6 inch pots).

Vote

Ray B 18 years ago

Interesting you would get that impression.

Catts and dens have pseudobulbs for storing water and nutrients, so can handle long dry periods. Phals don't, only having their fleshy leaves for storage, so generally need to stay constantly moist.

I also believe there is no such thing as a "best" potting medium for a specific plant. Yes, the watering needs of the plant play a role in medium selection, but so do the light level, air movement, temperature, humidity, and the watering tendencies of the grower, which of course, vary all over the map.

Some time ago I summarized a bit of that here:

formatting link

Vote