Posted: 27/05/2016 at 13:51
Personally I'd divide the area into 4 and just plant 4 different varieties into each of the 4 squares.
If just one bag is the only area available to you I would only grow stuff which is expensive to buy in the shops, which you can harvest nearly continuously and which is lovely to be able to use extravagantly. So I would grow herbs - perhaps chives, coriander, parsley and dill - they will all tolerate the same sort of conditions. Or you could go for ones which prefer drier / better drained conditions such as rosemary, thyme, oregano etc
With the exception of the coriander and dill I would buy in some plants in to ensure an early harvest. One supermarket parsley plant will divide very easily and give you 3 or 4 plants which is plenty. Same with thyme. Coriander and dill germinate quickly from seed.
Another expensive supermarket purchase are salad leaves and you could have perhaps 2 squares of leaves, a square of beetroot and a square of radishes.
Within each of the squares you could sow (thinly) half the area now and the other half in about 4 weeks. Beetroot and radish leaves can also be added to salads. Most salad leaves (lettuce, rocket, mizuna etc) can be treated as 'cut and come again' - so cut a few leaves and the plant will regrow new ones. Maybe 3 or 4 times per plant.