Our Mediterranean climate with its mild, wet winters offers us the opportunity to grow food year-round. Summer gardens right now are bursting with the vegetables that like warm weather, such as tomatoes, beans and squash. When the cooler weather arrives in late September, these plants start to fade, but many other vegetables thrive through the winter and can provide great fresh eating.

Now is the time to be planning for fall, winter and early spring vegetables. If you wait until the weather gets cool, you won’t have time to get many cool-season crops started.

Before you plant anything, consider your site. If you are starting a new plot, locate it where it will receive as much sunlight as possible during the winter. Most vegetable crops need at least six hours of sun daily. Buildings and evergreen trees cast longer shadows in fall and winter than in spring and summer and can limit the light available to your plants.

Whether planting in an established spot or new ground, take time to add amendments such as compost and fertilizer before planting. Growing food removes nutrients from the soil, and nourishing the soil will pay dividends in healthier, more robust plants and more abundant harvests. Also be prepared to water your vegetable garden until regular rainfall begins.

Let’s run through some techniques you might use from July through October to produce edible crops.

In July, one strategy is to plant crops that will grow quickly and mature before winter. You can plant seed directly in the ground for such crops as peas, carrots, beets, lettuce, fennel and kohlrabi. If the seed packet indicates that the crop matures in about 60 days (known as “days to maturity”), you will get nice results before Halloween.

Some cool-season crops, such as onions and leeks, need a longer growing season. These vegetables should also be planted from seed now. Green onions can be harvested immature during the winter, whenever the plants are large enough for your taste, but for large-size leeks and onions expect a spring harvest.

July is also the time to sow seeds in containers for transplanting into the ground later. Many vegetables are typically started this way, including celery, kale, broccoli, cabbage, cauliflower and Brussels sprouts. By starting your own seeds, you have a wider choice of varieties.

In August you can continue to plant vegetables from seed. The quick-growing ones, such as carrots and beets, may mature before winter sets in. But as the weather cools and days grow shorter, the vegetables will mature more slowly so you can delay harvest until you want to eat them.

Slower-growing crops will provide a harvest later in the winter or early spring. Look for the days-to-maturity on the seed packets to know what to expect.

August is also the time to transplant the vegetables you started from seed in July. If you didn’t sow your own seeds, shop nurseries early for the best seedling selection and quality. Many cool-season vegetables, such as broccoli and cabbage, will thrive through the winter and have the best flavor after they have been touched by frost.

My Napa winter garden always includes a variety of greens, both for salad and cooking. Lettuces are quick-growing plants that you can sow now and until mid-September. If you are sowing lettuces in July and August, plant in the shade of some larger plant or provide artificial shade as needed. Plant heat-resistant varieties while the weather is warm, then switch to winter varieties in September. By late September, you will need to plant seedlings, not seeds, in order to get good growth before cold weather.

Some other greens are very cold tolerant and will not only grow during our mild winter but thrive. These include mustard, kale, collards, arugula, chard, mesclun mixes and Asian greens such as mizuna and pac choi. If these greens do not mature fully in winter, they will grow rapidly and luxuriantly in early spring.

Greens are easy to start from seed and most grow quickly. They can be used as salad greens when young and cooked or stir-fried when mature.

You should be finished with planting by October, with one exception. In our area, November is the best time to plant garlic and shallots. Be sure to save a spot for these aromatic plants, which are easy to grow. During the winter, green (immature) garlic is a delicate treat, and garlic left to mature forms heads for harvest in late spring.

With a little planning and planting now, it is possible to have vegetables from your backyard all winter long.

Napa County Master Gardeners (http://cenapa.ucdavis.edu) answer questions Monday, Wednesday and Friday,    9 a.m. to noon, at the UC Cooperative Extension office, 1710 Soscol Ave., Suite 4, Napa, 253-4221, or (877) 279-3065.