Gardeners living in temperate zones often feel that vegetables can only be planted during the frost-free periods. However, some of the cold hardy vegetables can be planted up to six weeks prior to the average last killing spring frost. Certain vegetables also can be planted late in the fall and in the winter months in these temperate zone climates to take advantage of their early spring germination and development. These cool season vegetables include:

• lettuce
• peas
• spinach
• broccoli
• Brussel sprouts
• carrots
• radish
• cauliflower

Cool-season vegetables seeded too late in the spring are more susceptible to disease problems. A prime example is the powdery mildew that attacks peas during hot weather. Peas also yellow during these hot periods. Lettuce, spinach and chinese cabbage that is not planted early enough to take advantage of the cool spring will often bolt (form a seed stalk) when hot weather arrives. Radish planted during the heat will typically bolt instead of developing an enlarged root. Planting in the fall just before the ground freezes allows these cold-hardy vegetables the opportunity to develop early in the spring when soil and air temperatures are ideal for this category of vegetable. How to do it In the fall, after the garden has been cleared of all dead non-decomposed plant material (add this to the compost pile), till the garden area and mark the rows as if you were going to seed. Just before the ground freezes (or after if necessary) seed the desired cold-hardy vegetables, cover with soil from the garden or potting soil (if the garden soil is frozen). Cover the seed as directed on the package.

A layer of straw or hay mulch or even shredded leaves (as long as they do not pack down) will hellp keep the ground frozen and maintain moisture through the winter. A good inch (2.5 cm) of mulch is sufficient. Even small seedllings like carrots will come through an inch of mulch. The mulch will settle so by spring the inch that was applied will probably be about one-half inch (1.75 cm) thick. In areas where wind is a problem, mluch can be held in place with chicken wire or boughs broken from used Christmas trees. After the mulch is in place, soak the seeded area to provide sufficient moisture for germination. What about seed Most nurseries and garden centers return all unsold seed to seed companies in the fall. Some nurseries, however, purchase seed in bulk and then repackage. They should still have seed. If you had seed left over from last year, use it. It should still be good since all vegetable and flower seeds will store at room temperature for at least a year without significant loss of germination. Vegetable seed can be stored up to ten years if treated properly. Seeding closer than normal compensates for any reduced germination even when seed is several years old. Seedlings can always be thinned if more seed germinates than needed.