Emrys

Thanks for your tips

I think that you are starting the seeds too early with probably too much
heat and not enough of light and ventilation. In those conditions they
become leggy and weak.
Last year I started my Cosmos Sonata Mixed on the 11 April in moist
compost with clingfilm over it and they germinated in about four days in
a temperature of just over 70°, as recommended on the packet.

I watched them closely and removed the clingfilm promptly as soon as the
first seedlings appeared. Then I exposed them to maximum light and
ventilation in a temperature of about 50°. Turn the tray daily so that
maximum light is shared by all. I gradually hardened them off and
potted them up when they formed their second pair of leaves.

I intend to do the same again this year, weather permitting.

You have more than ample time to start again and that is what I
encourage you to do, using the above strategy as a guide. By all means
use the plant trays.

I started them a week last Sunday and placed them on top of a wall unit in
the utility room (which contains the boiler, though it's unlikely to be
70deg ) with a sheet of thick black plastic on top. After about 4 days, I
noticed them popping through and removed the plastic. I kept them up there
for a couple more days until they had all broken though and then placed them
on the dinning room table (!) I rotate and spray them daily.

It seems by initial temperature may not have been high enough and I waited
too long before exposing them to maximum light.......back to the garden
centre it s then :-(

Thanks

David