Here’s one of the best way to get plants up early and hardy ... well equipped for dealing with spring weather ... without need for space indoors or hardening off. This is SO low maintenance, you can pretty much chuck them outside and forget them until planting out time.
They get plenty of light and they don’t suffer rotting off in stale air.
Picture credit:
https://threepsandq.wordpress.com/2012/04/16/planting-updatewinter-sowing-and-square-foot-garden/
This year I was planning to winter sow in my green house but it got blown down! So I’m going back to my old stacks of milk bottle mini greenhouses ... so there’s a bit of recycling going on too.
I’m starting to save milk containers ready to sow all the veg and flower seeds that are pretty frost hardy.
I’ll use soil made in the garden and a marker pen & maybe a bit of duct tape. That it!
Each time we empty a milk container I’ll rinse & cut it and fill the bottom with soil and sow whatever takes my fancy (which would naturally grow in my climate). It’ll come up right when it is supposed to. It knows how!
Here’s a great explanation of how to go about it.
https://getbusygardening.com/winter-sowing-seeds/
Just be aware of slugs when the weather warms up.
The first year I did this I forgot about them and lost a lot of seedlings. I still had more than I’d achieved before learning about winter sowing.