[snails2go]

I have 2 outdoor cucumber plants (marketmore 76)

They've grown r e a l l y slowly, but have produced a couple of cucumbers each.  They now have loads of flowers/small cukes on them but they only seem to look healthy for about 24 hours at a time

I've given them more space (1 in each large growing tub), started watering through a partially sunk bottle so the stems don't get wet, feed them once a week with Tomorite and treat the mildew with a milk/water spray (removing the worst affected leaves) and still every other day they are covered in a white powery mildew.  The tops of the plants are starting to look really healthy now that the weather has warmed up, but I know it wont last!

How do I keep them healthy?

[Trillium]

Sounds like your cukes need even more water than you give them. I literally drench mine almost every day because they need so much water. I personally don't use fertilizer, but rather lots of rotted manure and BFB.

Plus, they really do need heat. Lots of heat. Or they won't fruit. If you can put them into some sort of large cloche or coldframe next year, you'll find they'll do better for you. People forget cukes are more of a tropical plant and can't take low daytime or nighttime temps.Once we got lots of heat, I've had to give many away as I can't keep up with production (from only 6 plants)

[blackisgreen]

lots of food and water oh and heat

[snails2go]

Thanks - I'll increase the water and I have a pop up greenhouse tunnel thing so at least one of them can go in that :-)

Fingers crossed 

[viettaclark]

This year I'm trying the cukes in the soil which is very rich with my compost, manure and fbb. I find I don't have to water so much compared with pot growing.
I kept 12 assorted ones (Marketmore, Wautoma and Long White) and gave away at least another 12 (fantastically unexpected germination!). They were in small pots for too long and I didn't protect them enough during those cold spells so they were a sorry sight when I eventually planted them out and I quickly lost most of them. They were all crisp and brown then I noticed little rosettes of green growing as soon as the weather changed and got warmer.
Now, I think 6 have actually survived and I had my first baby cuke for lunch! More flowers are coming on 4 of them so fingers crossed I may even get a few! What an amazing difference heat makes!
Then today I spotted the mildew......