Reconsidering growbags in the greenhouse

I had planned to do toms, peppers, aubergines and a melon in growbags (with bottomless pots on top), but I've heard they dry out really quickly and are hard to keep watered. If I use the growbag contents in pots, what size pot would I need for each plant please? 12 inches across? Bigger? The reason I ask is because Lidl are currently doing big plastic pots 43cm (18 inches?) across, and they're half the price of comparable pots in Homebase, so I was going to stock up today if necessary.

Perfect - thanks

try standing your pots on trays of gravel or hydroleca to reduce the watering problems.

Not as pretty as pots but Im a big fan of cheap black plastic buckets with holes drilled in the bottom for drainage. At about a quid each they're cheaper than the equivalent size pot, and seem to be considerably more robust.

I tried some Toms in a Growbag with pots on top last year - wont be doing it again this.

Any idea where I'd get those buckets? They sound good. I'll look in the Poundshop type place near us tomorrow.

If you visit a local supermarket beginning with T they are usually more than happy to give away the black plastick buckets their cut flowers are sold in.  There are 3 different sizes and, over the last few days, I have picked up 4 large, 20 mid and 37 small ones!  For free!!!!

Last year i grew melons just in growbags,yes they do need careful watching for drying out but they worked for me and i got 12 beautiful delicious melons.Ive seen some kind of a bag automatic watering system in the organic gardening catalogue which i may try this year

Thanks for the tips. I was planning on mixing in some swell gel - would that help?

Not sure how that lasts over time - but i would think vermiculite would help.