Seedling mix question.

[King_of_orchid_growing:)]

Boil the Sphagnum moss. Squeeze the Sphagnum moss until it is damp. Do not allow the Sphagnum moss to stay sopping wet. Then I would just lay the boiled Sphagnum moss in a tray with drainage holes, then place the seedlings on top of the moss. Spray with a fungicide. Serenade Garden Disease Control Concentrate is a brand of biofungicide that I think is ok as a preventative measure. There are other brands of biofungicides and there are at least a couple of species of bacteria used as such, (Bacillus subtilis strain QST713 and Bacillus amyloliquefaciens strain D747). Cover the entire tray with a vented dome. A nice humidity dome is cheap to make yourself or to buy. I would start them off in a shady location first. Phalaenopsis level light should be good enough until they get larger. Do not fertilize until the seedlings start growing more roots.

The question about why orchid seedlings respond better when grown together is sort of not that well understood. Botanists are just starting to understand that plants indeed do communicate with one another by chemical means. Plant siblings can recognize each other and can also detect whether their neighbor are not their siblings even though all plants belong to the same species. Siblings have also been shown to be able to share resources and not compete against one another for those same resources. There might be some sort of survival mechanism involved, but what that is, I cannot say definitively at the moment.

Expect some heavy losses if you are getting seedlings at this stage in life.