brittle roots in a dendrobium nobile

[zygophalden]

Originally Posted by Veksa

Where do you live? Do you have Ikea?

I have IKEA but they don't sell it there for some reason last time I checked. However, If I am not wrong, Leca is clay pebbles? if so, I believe I found where to buy. Are there sizes or certain kinds of LECA?

[Roberta]

If LECA or similar medium isn't readily available, any inorganic, porous material will suffice, mixed with bark, to help maintain an open and airy mix. I use perlite, which is a human-made material that I think is mostly silica. Pumice is a porous volcanic material. The details aren't important. In fact, with good-quality bark that is medium-size or larger (1.5 cm or larger) no amendment at all is really necessary. The goal is a medium that drains well and has plenty of air space (since Dendrobiums, and most other orchids, really want "moist air" more than "wet".)

[zygophalden]

Originally Posted by Roberta

If LECA or similar medium isn't readily available, any inorganic, porous material will suffice, mixed with bark, to help maintain an open and airy mix. I use perlite, which is a human-made material that I think is mostly silica. Pumice is a porous volcanic material. The details aren't important. In fact, with good-quality bark that is medium-size or larger (1.5 cm or larger) no amendment at all is really necessary. The goal is a medium that drains well and has plenty of air space (since Dendrobiums, and most other orchids, really want "moist air" more than "wet".)

Should the mix be 50-50 or the perlite needs to be arranged in a certain way? Up until now I only repotted phals in bark and coco so not entirely sure how to repot dendrobium.

[Roberta]

Originally Posted by zygophalden

Should the mix be 50-50 or the perlite needs to be arranged in a certain way? Up until now I only repotted phals in bark and coco so not entirely sure how to repot dendrobium.

I use about 1/3 perlite and 2/3 bark for nearly everything.(For Catts in large - 2 or 3 cm-bark I don't use any perlite at all) It doesn't need to be precise. The perlite just helps to keep the mix open as the bark ages. I just dump it all into the same bucket and mix as well as I can.

Another note about perlite - what is often sold in garden centers is very fine - designed to be a soil amendment. Don't use that! I am able to get some that is larger - about 1 cm pieces. If you can't get that, use something else - pumice perhaps - or just use bark and skip the amendment. That fine stuff will do the opposite of what it is supposed to, fill the air spaces instead of keeping them open.

[aliceinwl]

I have a bunch of D. nobile types and they’re really not too picky. Anything that breaths well works. I have most of them in the same bark mix I use for my Phals: 5 parts small bark, 1 part medium perlite, 1 part charcoal. I have one big one that’s still in moss. I have some in plastic slotted pots, some in plastic pots with only bottom drainage, some in clay. I’m liking the clay best because of the added weight. I’ve got some growing inside and outside. These throw a lot of keikis so it’s easy to end up with a lot of plants.

I tend to water the indoor ones weekly during the growing season then starting in November I only water when the cane starts to wrinkle. For the outdoor ones which are in full sun most of the day, I water near daily during the growing season. I left them out last winter in the rain so I didn’t get many blooms, the year before I kept them sheltered and only watered occasionally and got a decent show. This year, I’ll shelter them again and water only if I see cane wilting (this got the smaller keikis growing inside to flower well so it should work for the parents too).