Succession gardening means planting a second or third crop where another crop has finished – this way you can always be using your garden space for more fresh produce as well as preserving for the winter.  Once early maturing plants have finished, plant a second crop in their place (to get a head try starting plants in Jiffy peat pots).  After your second planting has been harvested you can usually plant a cool weather crop for late season enjoyment.  The key is to check on the seed packet for the days for germination and maturity, add them together and then check the number of days back from a likely first frost date for your region to make sure you plant to allow enough time for your next planting to mature.  Most greens (lettuce, kale, endive, spinach), radishes, bush beans and peas can be planted mid summer and harvested in the fall for regions with a September/October first frost date.