A growbag is a big plastic bag of peat or compost. You lay the growbag on your patio, deck, balcony, wherever and cut holes in the top of it for the plants to go in. The plastic bag keeps the warmth and moisture in, the plants grow out of the top.

I see from Google that 'growbags' are what they are now calling those 'babygro' things with sleeping bag-like bottoms rather than legs. Do not get the two confused. One is not waterproof.

Zany - Lakeland Plastics used to sell a 'growbag greenhouse' which was a pop-up green house made of plastic that had shelves in it for 2-3 growbags. I don't know if they still do them, the catalogue didn't show them earlier.

B&Q might do something similar.

LTS