compost for dendrobiums

[gaynes]

Hi everyone, I'm new here; I'm a Brit teaching & living in China in a temperate climate, but summers are warm & humid. Easter bunny came today; Chinese style. I found 5 dendrobiums (fairly common purple ones) in a dustbin! They are all in clear flexible plastic pots & very waterlogged & in various states of flower drop. They are each attached to a curved plastic support with butterfly-type hair clip things. The problem is, I have some compost from when I bought some bulbs before Xmas in the market, but DEFINITELY wont find the real deal for orchids in this 1 horse little town, even if I COULD ask for it! We do have pine trees on campus & was wondering if I should break up bark or pine cones & needles to add? How can I improvise in the absence of a bag of commercial orchid compost. Thanks for help!

[RosieC]

Hi Gaynes and welcome to Orchid Board

I believe that plain bark or pine cones will not be good as they will release oils that are not good for the orchids. Usually the stuff you buy is cooked at a really high temp to dry it out and remove/kill anything bad in it. You don't want to use ordinary potting compost for orchids either.

I know some people here taken pieces of wood and cook it in the oven for mounting, so I'm not sure if something similar can be done.

I think sometimes people out in that area of the world grow in charcoal, can you get hold of that at all? (Although make sure it's not the stuff you get over here with firelighter chemicals in it).

What is the medium they are in at the momment?

[got ants]

I have to try it myself but I have a ton of bamboo I plan to cut into chunks for medium. That and coconuts. Oh, and of course hardwood charcoal from the campfires...

[dounoharm]

the charcoal would be good, and so would the coconut fiber if you can chunk it up.....bamboo i dont know about except that it will sprout if it has any life left in it at all, and of course you dont want that...i would go with the coconut and charcoal....gl!!

[gaynes]

Thanks everyone for the prompt replies- I'm impressed. OK today I removed 3 plants from their pots-1 with no leaves, 1 with a leaf which fell away from a rotted base, & 1 with 2 leaves. All have long flower spikes, all dead, dying or rotting at the spike ends which have buds. They were all choked up in sodden sphagnum moss & the fleshy parts of the roots fell away as I was removing the moss, leaving the white, tough, thread like 'inner' part of the roots. All roots green, black in some cases. I cut off all the rotting bits ie just about everything. I collected bits of dead bamboo, & various kinds of bark which i have been pouring boiling water over & soaking; ditto the sphag moss which is now drying in the sun. Also bought a bag of compost with a picture of an orchid on the front. I'm planning to use a bit of everything. BUT.. should I cut off the flower spikes, or just the dead bits at the end? Thanks again

[got ants]

gaynes, the whole thing about orchid "compost" bothers me. Generally new potting material should be fresh, not composting.

Maybe it's a language barrier, but most potting mediums are replaced when they start breaking down.."composting".

As for flower spikes, depending on the plant, some rebloom or produce keikis, which are miniature new plants. The rule of thumb I use is only cut when brown. Even if I know the plant is not going to rebloom or keiki, I wait for the flower stalk to recycle nutrients back into the plant.