Johntheeng

Onion help.

Poor weather, not enough sun ?

Possible to sow more peas and beans

Zoomer44, What type and when sown please. I would like some this early next year.

Cucumbers

I always water mine from the top and never have problems doing it. Mine are in pots in an unheated green house. I never put them there until temperatures are favourable i.e. above 7deg. constantly at night. The greenhouse is kept well ventilated. Are your plants in good compost and well ventilated ?  As Italophile says it could be other things than temperature. In one of my books it points to Basal Stem Rot. This is caused by over watering and too much water at the base of the stem. Symptons shown are the leaves wilting and the plant collapsing. Hope this is of some help.

Drooping Cucumber Plants

Try and give it some heat if you can because it seems that its been too cold for it. If you can its always better to wait until mid June before putting cucumber in the open.

Good luck with them anyway.

Filling a raised bed

Top soil and manure. Wintersong has said it all really.

sowing veg seed in plastic guttering

I have never grown root crops in guttering but have started off peas in them before sliding them off into the beds when big enough. Salad crops are good in guttering especially radish.

planting broad beans

I always start mine off in home made paper pots and then plant the whole lot into the ground when the plants are about 4" high. I get good germination this way in a cold green house and there are no spaces in the beds when planted out.

Raised bed depth

The longer you make raised beds the further you will have to walk to get to the other side. I agree 4ft wide is the widest to make them.

Roses

Sweet corn