den. kinganium media problem - plz help
 

i have a nice small den. king who i have been slowly killing for long time now - it had nice roots, then i gave it far to much water, killing all its roots.
Then i grow some new ones, and i am now so so scared to kill them to - having a big problem to know when to water - my media seem to hold far to much water for this guy!

Then i wonder - i have 8L of vulcan rook - it is small stones and gray - it is sold here in denmark as a growing media for people with allergy.
can this be use as only media for my den?

Vulcan rook (rock?) can be used as far as I know but what I would be worried about is the mineral content. I use plain bark for my Aussie Dendrobiums and that seems to work very well. I use medium grade fir bark and added LECA (expanded clay pebbles) to keep the mix open. A larger plant is potted in a terra cotta pot, which helps to dry the medium even faster.

My limited experience with this kind of Den's learned me that they like a very airy medium. Lots of air around the roots allows good watering.

Erce,

I grow all my dendrobium kingianums in an 80% fine bark/20% medium sponge rok (expanded perlite) media in plastic pots outside with all my Cymbidiums all year long in Northern CA. Some of the larger ones are hung but all receive an essentially 50% sunny condition. I fertilize with a combination of 13/13/13 slow release granules and an added liquid fertilizer applied at the weekly watering at least once a month.

My biggest problem with them is their outgrowing their pots within 2-3 years but they bloom as specimen plants! Hope this helps. Err on the side of too little water rather than too much and your local conditions will play a large part too in this.

I would shy away from volcanic rock as it holds too many salts and sooner rather than later, will cause the roots to die.

CL

There's no need to worry about the mineral content of the rocks. Den. kingianum is a lithophyte. It usually grows on granite or sandstone in Australia. Wet spring and summers. Drier fall and winters. Bright indirect light.

They've also been known to grow as epiphytes in the wild as well.