Kitchen Garden Forum

Good morning.

Any ideas why my cucumber plants have started to get yellow leaves. They're about 8 inches tall and were sown at the end of March. I've been careful to protect them from cold and have been bringing them into the house (from the greenhouse) at night. Could it be a lack of nutrients in the soil now that they're coming up for planting out? Many thanks.

You have answered your own question. Yes they need a feed and yes they need potting up into their big girl pots now. But the yellow leaves at the base will probably stay that way now.
Regards Sally Wright.

I read somewhere 3 tips for growing cucumbers.

1: never let their growth be stalled by not potting them on when needed.
2: remember, although they are in the same greenhouse, they are a squash, not a tomato ! Use feed with enough N, not tomato feed that is mostly K.
3: I forgot no 3

I would add my own speculation that peat free composts are often rich in poorly composted wood waste. The continuing fungal decomposition of this may deplete nitrogen, so the plants seem to run out of steam. It can be worth feeding earlier, and maybe with more nitrogen. But that is all IMHO.

Regrettably cucumbers are like sheep, they have more ways of dying than living.

Evening Tony,
Try telling Monty Don about your opinion on peat free compost.It will go in one ear and out the other!!!

I should say I didn't intend that to advocate peat based composts - just that you might need to adjust your feeding regime. I've used New Horizons for many years, and as I've often said, the only thing consistent about it is that the bag size will be smaller than last years. Last years seemed quite good, mostly coir based and no bits of shredded kitchen cabinet. This year not so good, I think.

For most things I'm using my own sieved garden compost blend, of which I have a lot. But - coming back to cucumbers - I found last year that it was fatal to my cucumbers - stem rot at the base. Whether disease, or simply too heavy/not free enough draining, I don't quite know.

Many thanks all for the most useful advice. I'll be potting them into big pots now and hopefully that will sort them out. Just need to watch out for those low temperatures we're having at night!

Interesting point about the no-peat compost, which I do generally use, although I'd not been able to get hold of it earlier this year and had to buy a couple of bags of peat based compost to get my seeds and young plants started.

Re Tony's quote ".... remember, although they are in the same greenhouse, they are a squash, not a tomato ! Use feed with enough N, not tomato feed that is mostly K." Could you suggest a plant food higher in nitrogen?

Following on from your cucumber problem, HelenH, I have a different issue....shop bought cucumber plant has gone all floppy. The one I've grown from seed is fine, I only had 1 come up, so had to order another from the garden centre with my compost delivery. I've checked around the stem, and it is sound. It just went like this about 3-4 days ago.

Retropants - This happened to one of my other cucumber plants but it was earlier in the season and I think it may have been caught by the cold as my greenhouse isn't heated. On the other hand too much full sun can make young plants wilt, so could it be a fluctuation in temperature that has caused the problem - but then the other cucumber is ok! Trying to balance out the extremes of temperatures in the greenhouse at the moment can be difficult .. almost like desert conditions!

Thanks HelenH. Will it come back to life -via side shoots etc- do you think? I'm pretty sure it's done for.

Retropants it doesn't look great but neither did mine so it could pull through!

HelenH - can I ask, was it just the very bottom two leaves on your plants that went yellow, or others further up as well? I thought the very bottom two were the 'seed leaves' or spent cotyledons from the seed and once they've given all their fuel to the plant they die off anyway. I've got a few cucumbers coming on and don't want to panic if I don't have to. With those cold nights ahead at the weekend, I'll be panicking enough!

Vivienz: Yes, It is just the two bottom leaves on each plant that have gone yellow, but the remaining leaves aren't as 'green' as they could be. I'm potting them into bigger pots this weekend as I think they're starving! With the predicted icy blast looming on Sunday evening, I could do with bringing them into the house as they're the most tender plants in the greenhouse. Beginning to panic about not having enough fleece to cover over plants!

Cucumbers that have gone floppy on me have always had same sort of stem rot. They don't recover. I lost my first lot like that last year. I don't know if it was something in ths compost, or it was poorly draining, or I just planted them too deep.

When I have the choice, I'd use a general purpose veg liquid feed rather than a tomato feed. This year I haven't got any, so I've nade this:

Its a pipe, with the bottom end capped of but for a tube into the collecting bottle. Comfrey and nettles in the top, weight down with the champers bottle full of builders sand, liquid feed out of the bottom. Satisfyingly, all made from accumulated useful bits of junk in the garage. It does produce - without a bad snell - a brown liquid result. Give me a few weeks and I might know if it makes the plants grow !