Hi Steve,

First I always bake my propagating medium in the oven before planting gesneriad seeds. A temperature of 175 to 200 degrees for around 3 hours does a good job of killing anything off. Also if you are having trouble with algae you are probably keeping the potting medium way to damp.

Good luck,

Larry

I've used Funginex in this manner when sowing seeds of Bletillas and it's been successful in preventing fungus, although it won't do anything to prevent algae. Gesneriad seeds usually germinate and grow faster than orchids and don't have problems with fungus, so I haven't tried it with them.

I do exactly the same thing as Larry B. I make up a batch of seed starting mix every few years and store it in a covered container. My mix is peatmoss,perlite, and vermiculite. Lately I have had good results from making up a second batch of screened peatmoss, which I cook like above. This I mix in a small glass with water, make a slurry and spoon over the pot of my regular seed starting mix. It makes a thin dark very wet layer of peat, on top of which, I sow my seeds. Then I label and enclose the seeds in a small ziplock bag and place under lights. The only problem is dividing the seedlings as the germination rate is very high. Older seeds take longer to germinate. I will get some fresh seeds to sprout in a week, but typical gesneriad seeds take about three weeks before I see tiny tiny little green plants on the moss. I rarely get any moss, algae, mold, liverworts, ferns or whatever when I cook the mix for at least three hours beforehand. This mix has no fertility so the seedlings will need to be fertilized after they germinate, otherwise they will not grow and eventually turn white. Feeding will bring them back even when they turn snow white.

Jon