I live in an apartment and this year started gardening in containers on my balcony, starting with organic potting soil. I want to do everything organically. I don't know what I should be doing to maintain the soil as plants grow. I have been adding an organic liquid kelp food. I also don't know what to do with the soil once the growing season is over. Should I obtain organic compost and mix it in? What should the ratio of soil to compost? Should I be adding other (organic) nutrients? I read once that you should reuse soil from year to year in containers because bacteria can become a problem, but an organic farmer (who doesn't garden in containers) suggested that if i just spread the soil out and left it in the sun for some time (I'm not sure how long), that would be fine. As organic soil is expensive, I'd rather not keep buying it annually!
I started out by growing pole beans (good results- even in fairly small containers!), snow peas (ok - got powder mildew but will try the one part milk-9 parts water spray next time), dill (ok), basil (ok), tomatoes (not sure-still in progress; lots of foliage, not much fruit), cilantro (very poor results), spearmint (never germinated after 2 tries), thyme (very slow growing). I live in San Diego so there's plenty of sun and can garden year round. All my seeds were organic/heirloom varieties from a place in Port Townsend, Washington.