an idea i have thought about too. for tomatoes look for determinate(hope that is the right word) they grow a certain size then quit growing to produce fruit. indeterminate keep growing and you get fruits at different times rather than all at once. these are usually the vining tomatoes. also you can start new tomato plants from cuttings. i have been thinking about hot peppers since they dont do well in the garden here and to have plants for spring and peppers for winter. cilantro and dill are my favorite herbs so i might try those too. i think i have seen somewhere that eggplant does well too.