Does anyone know why my cucumbers are growing in a funny shape?

[MissGreatBritain]

I've had 3 or 4 so far, which have looked normal (and tasted fab). but the new ones that are beginning to grow seem to have about 2 inches of normal cucmber then a really thin middle then a fatter bit at the other end (a bit of an hourglass shape really). will they fatten up, or am I doing something wrong?

Sounds like they haven't pollinated properly - are they inside or out? If in a greenhouse/tunnel perhaps open the doors/windows more to let insects in? If outside has it been very wet or very hot & dry - either might have meant that they didn't pollinate so well.

i once grew some carrots that were about 5 inches long and half a cm wide, they were so odd, i gave up

Irregular watering? have you left long gaps then too much water? think they need regular constant watering.

Well, I think they've pollinated ok as the greenhouse door is open all day. Maybe it has more to do with watering as I was ill for a few days and didn't get out there as much as I should have done. thanks for all your suggestions.