Courgettes in buckets

[Ken the Chef]

The top growth is nice and green but the earlier leaves are tuning a pale green/yellow,
The plants [3] are still producing fruits.
I have been keeping them well watered and fed with the liquid from my wormery diluted 20 to 1.
Should I be thinking of feeding any thing else.
I'm sure something is not quite right

[vicky]

If they've been fruiting their little hearts out for the last month or so they may well be feeling a bit tired! Courgettes plants have a peak of production and after that they go downhill. Plants in tubs seem to start and bit earlier and therefore burn out a bit earlier too. Just keep looking after them - you sound like you are doing things right. You will keep getting courgettes but production may slow down. The yellow first leaves can be cut off without harming the plants.
It is worth having some plants germinated later to take over when this happens next year (although if they've been very productive you might be sick of courgettes by then?)