Cucumbers

[KINAISAAC194]

Please can someone tell me why my cucumbers collapse, there are in 3" fiber pots with seed compost, just after they appear I put them on the windowsill with no cover but when they get to 3/4" very quick and then just collapse and die

[Clanad]

Sounds suspiciously like Damping-off... Usually seen in seeds planted directly to the garden soil. I suspect you are re-using planting containers that may have become infected with soil borne virus. Try new pots and new soil. Additionally, seeds should indicate on the packet treatment for various viruses... Best of luck!

[KINAISAAC194]

They are new pots in new seed compost and I keep the soil just over damp

[Clanad]

Are they last years seeds?

[KINAISAAC194]

New seeds

[KINAISAAC194]

At night they are taken off the window and put in the room

[shepherdess]

It can still be a form of damping off even if the seeds and compost are new. Try keeping them on the dry side (you say you keep the compost just over damp - not quite sure what you mean by this?) and see if this helps. Lack of heat and too much water is not a good combination.

[KINAISAAC194]

I think it could be the Double glazing keeping the sun light rays out

[shepherdess]

Double glazing should not make any difference. A big temperature change between night and daytime will not help as the seedlings do not like to be too cold, particularly if the soil is wet.