[cbo1170]

Hi, I'm new to this forum, and gardening in general, so apologies if this topic has been raised before.
I've grown cucumbers from seed this year and so far it has gone ok with five plants growing.
Over the past few days the leaves on the young plants have started to turn yellow and I've no idea why. They're in a greenhouse and I water them when they need it, but they seem weak and look like they're not going to last.
If anyone can offer advice I'd really appreciate it. I've added photos to help.

[Aunt Sally]

I think they probably need feeding.  Liquid sea weed would probably be best, otherwise whatever you have.

But don’t overwater them !

[cbo1170]

Hi Aunt Sally,
Thanks for the advice. I have some tomorite, would that do? I can always buy some liquid seaweed if not.
Thanks again.

[Aunt Sally]

That would be fine 

But if the soil is already wet just spray it on the leaves as a folia feed.

[Vagabond]

Hi, cbo - I'd be interested to know if your cucumbers recovered after feeding.
I'm trying cucumbers for the first time this year, so reading as much about them as possible.

[mikem]

A question for others, could it be that the greenhouse is too cold at the moment?

[Twood]

I'm growing cucumbers this year but I only leave them in the greenhouse during the day and bring them back into the house overnight
Apparently they dont like the drop intemperate too much
Obviously as the nights warm up they will probably stay in the greenhouse overnight.
Vagabond - dont over water and they dont like water touching the stems because the next thing you know the whole thing just collapses and is a gonna.
Although you can see from the picture I'm desperately trying to save the one that fell over at the weekend. Its surviving but isn't growing as well as the other one.
However there is a back up on the way

Good luck
Twood

[Vagabond]

Thanks, Twood - I'll take care with the watering. I only have three viable seedlings.  Two are destined for growbags in the greenhouse and one will go outside. The variety is Marketmore and it's supposed to be suitable for growing outdoors, but I thought I'd hedge my bets.

[JayG]

Bear in mind that Marketmore is a ridge cucumber which requires pollination to set fruit - you may need to manually pollinate the plants in the greenhouse using an artist's paintbrush or similar if there are no pollinating insects around to do it for you.

[Vagabond]

Ah, thanks for that tip, JayG. I'm a greenhouse virgin, so clueless about manually pollinating plants! (I feel a Youtube video coming on)