After an abysmal round of jiffy-soil failures, then finding and reading tips here, I have a lot of happy seedlings except for:
Collards - sprouted to tiny size ( less than 1 cm) and still there after six weeks
Poppies - sprouted and stalled also, but absolutely hair-thin, then they fall over and die
Corriander - keeps getting taller and taller until it falls from its own weight
Ive used a couple of different potting mixes, which work well for the other plants. I have a heating pad under 1/2 of them but it does not seem to matter, and I've tried both top and bottom watering.
Thanks in advance if anyone can shed some light on what mistakes i am making.