£ one pound grow bags with baby bio at ten drops per gallon of watering water stood on your balcony should allow you to grow lettuce and radish anong with tomato , peas and spring onions .for a year before needing some serious work
A packet of mixed salad sown and grown as cut and come qgain should see you right through till the first frosts ,
If you can stand the bags up on their ends so they dont fall over you can also grow carrots and beet root as the depth of soil will be greater .
Potatoes can be grown in a strong black rubbish bag s, poke a few small drain holes in the bottom of a bag add four inches of compost , plant five potatoes and cover with four more inches . Roll the top down and water well , keep it watered but not too much , when the spud greenery reaches nine inches tall roll the bag up add three inches of compost & water it well . Do this in there inch stages till the bag is full .
You can harvest the spuds when the flowers appear but leaving them till the y have dies is usually going to see you get bigger spuds .
Ornamental cabbages are usually smaller than a normal cabbage and do well in balcony pots & bags.
Don't throw the spent compost away , use it in other plant pots so long as it is not for potaotes or tomatoes as they are the same family and disease otherwise build up.
There are a lot of websites that deal with soil less growing / growth medium or balcony gardening .. google the likely names and you'll be amazed at what is being grown on balconies.
Put up a list of what seeds you have and what else you want .Also PM me your name & address & I'll send you a few seeds.