Don't know. More work then I am willing to do. I just start them in shallow trays (2 inch deep) and normally a thousand plants. Just pull and plant. I start a 1000 plants.

Agree - more work and more expense as it would take extra equipment, more lights, and potting mix, etc.

Onion seeds don't keep well for more than a year anyway as the germination rate falls off fast. I agree you need to start them much earlier but there there are usually 250-500 seeds in a pack (at least) so you just plant them all in one tray. When ready to plant you just separate out a chunk like farmerdill shows in this photo pull them apart as need and plant. Sure a few may not make it but 95% of them will do fine.

Many folks, myself included, plant them in small clumps and then thin out some as they grow to use as green salad onions.

Dave

Don't worry too much about spending time fanning out the roots perfectly. Most of the plants grow fine if you just poke a hole into the soil and stick in the seedling.

I grow my onion and leek seedlings in reused yogurt tubs. ~40 per tub. When I am ready to plant I carefully remove the bunch from the tub and swoosh them around in a bucket of water to remove the potting mix from the roots. Having them bare root makes separating much easier. Then I trim the roots to about 2" which makes them much easier to plant. I don't grow nearly as many as farmerdill though and would probably use 1020 trays if I did.

Garden pictures · More Info

Garden pictures · More Info