At my house i have a big compost pile that we throw all our food waste and grass clippings in then when thats all broken down we sift it and put it in a big pile for making gardens. Now my questions is about compost as a fert i have around 10 to 15 plants all at different heights (from 3''-12'') the larger ones in store bought potting mix. at what point should i use compost and what should i use the actual food stuff,semi broken down stuff, or the pile of 2 year old compost turned into dirt?