[newseed]

I have cucumber plants about 5-6" tall (abit leggy) and the leaves have started to turn yellow.  They are in a plastic greenhouse and kept well watered as with the Toms and  courgettes I have not fed them yet could this be the problem? any help appreciated.

[gobs]

Nutrient deficiency is quite rare in young seedlings, rather the number of their true leaves matter here, not the height.

Yellowing of leaves can happen for a multitude of reasons, too wet, too dry, too hot or too cold being just a few.

[DD.]

It may well be due to the large flucuations in temperatures. Of late is been hot during the day & very cold at night - as my spuds will testify!