As the days get shorter, it’s the perfect time to plan a fall vegetable garden. Cool-season edibles are some of the hardiest that you can grow. Examples of herbs and vegetables that can be planted from now until the end of the month are broccoli, cauliflower, cabbage, mustard, lettuce, onions, radishes and garlic. Cold temperatures can actually improve the flavor and texture of thick leaves on kale, collard greens, cabbage and turnip greens.
The key to fall gardening is estimating the timing correctly. Reduced radiation from the angle of the sun and shorter day lengths are the greatest challenges for producing vegetables in the fall and winter months.
To be sure that vegetables are mature enough to handle the first few frosts, use transplants for fall crops such as broccoli, cauliflower, cabbage and Brussels sprouts available at your local garden center. Seeds for leafy green plants can be planted this weekend, such as lettuce, arugula, cress and spinach.
If a crop requires six weeks to mature, plant six weeks before the average fall frost date in your area for hardy vegetables that will continue growing through the low temperatures. It’s always better to install early and give your plants time to mature. A fall vegetable garden is especially worth trying because of the warm conditions we’ve experienced this season.
• Radishes are a cool-season root crop like turnips. Most radish varieties have a globular root and pungent taste generally eaten raw in salads or used as a garnish. Plant now from seeds. The tender new tops of radish plants can also be eaten as fresh greens. The large elongated daikon radish is peeled and cooked before consumption. Both are a source of vitamin C and potassium and low in calories. They mature quickly, usually ready to harvest in three to six weeks.
• Garlic is planted as an individual clove, carefully separated from a bulb, which might contain as many as 15 to 20 cloves. In colder climates, they are planted in the fall, about six weeks before the soil freezes (by Sept. 30) and harvested in late spring. The Washington region might not experience temperatures below freezing until about Nov. 1, according to Maryland Department of Agriculture, Ag Statistics.
• Broccoli installed by mid-September, as started plants, should be maturing about the time we receive our first deep winter frost.
• Cabbage planted within the first two weeks of September can be harvested until the middle to end of November since it is a cool-season crop that will stand up to the first few frosts.
• Chard, often referred to as Swiss chard, thrives in cool weather. Once it is established, the foliage will grow and you can harvest it into cold weather (33 degrees Fahrenheit). Usually it will take a hard freeze to kill the leaves. It requires a sunny, well-drained site and soil rich in humus.
• Spinach is a cool-season plant that you can harvest when it reaches about three inches in height. It will grow until late fall without an early frost.
• Kale is in the cabbage family, and the growth looks like a leafy cabbage that grows with an upright habit. It is a biennial that will leaf the first year, flower and go to seed the second year of growth, and then die. Allow a portion of the plants to display their yellow or white flowers so that they can go to seed. Kale will return annually from the seeds dropped the previous year.
• Leaf lettuces should be grown with room between leaves for air circulation. They will renew rather quickly if given enough sun and soil rich in compost. Because they prefer cool weather, you will be able to harvest lettuce as long as the temperature remains above freezing. Sow seeds now and keep moist.
• Onions come in many varieties and are closely related in aroma and use. There are leeks, Japanese bunching onions, bulb onions, chives, walking onions and many others. Install in autumn and they will begin growing next spring. Onions are healthy food crops and when in flower can be quite ornamental.
• Celery, a biennial, is a cool-season vegetable that drops its seeds in fall and grows as an aromatic herb in spring. It has tiny yellow flowers that bloom, go to seed on alternating years, and grow leaves when the seeds germinate the following year. It was well known to the ancient Chinese, Egyptians, Greeks and Romans. The parts of the plants that are eaten are the leaf stalks (celery), leaves (Chinese celery), root (celeriac) and the fruits (celery seeds). Celeriac (the root) is commonly blanched and it is a traditional vegetable eaten in central, eastern and northern Europe.
• Burdock plants are perennials that sport large leaves and have a long history of medicinal use in Europe and Asia. The young tender roots are most commonly used in Japan as a food crop. They are harvested before they become fibrous and difficult to prepare and eat. The fruits are burrs that will stick to your clothing. Leaves and fruits are not used for food. Its medicinal uses are for skin irritation and rheumatism and as a diuretic.
• Horseradish is a perennial herb with numerous large leaves growing from its thick taproot. It has small white flowers and small fruits that do not form viable seeds. It is grown from root cuttings. The edible part of this herb is its fleshy roots that have a hot, peppery taste and sharp smell from the mustard oil glycosides that they produce. It is most commonly used, sparingly, to flavor meat and fish dishes. Wash and peel the skin of the root and grate it into dressings to flavor meat, fish, potatoes and salads. It is a popular seasoning in the Alsace, Germany, Russia and Scandinavia.
The following preparation is commonly taken to plant seeds of radishes, lettuce, arugula, celery, burdock and other cool-season crops planted now. Use the same cultural practices for planting tubers such as potatoes, turnips and beets in fall:
1. Cultivate an inch of compost into the top two to three inches of soil.
2. Scatter the seeds lightly where you want them to grow.
3. Very lightly slide an upside-down lawn or leaf rake over the planting bed barely covering the seed.
4. Sprinkle with water. Continue to lightly sprinkle three to four times a week through dry periods.
5. Protect the roots of young plants in winter with a mulch of aged leaves or bark.
Joel M. Lerner is president of Environmental Design in Capitol View Park, Md.