It's time to plant cool-season vegetables

As soon as soil is ready to be worked, you can start planting cool-season vegetables. Radishes, beets, carrots, broccoli, kohlrabi, cabbage, and leafy greens are just a few of the vegetables that relish cooler temperatures and can handle some light frosts.

Begin by improving the soil. It is not the sexy part of gardening, but it is the most important. The time you spend now will pay you back in dividends. Add lots of organic matter. It encourages beneficial microbial activity in the soil and improves the soil texture.

Plant the following vegetables early in spring and you will be eating homegrown vegetables before you know it.

Beets are most often grown for their roots, but their tops are delicious in salads when they are young. Older tops can be cooked. In fact, the green parts of beets offer more nutrition than their roots. There are varieties available with white, yellow or red roots.

Plant seeds directly into well-prepared soil in an area that receives lots of sun. Plant them one-half inch deep and one inch apart. As seedlings grow, thin them to 3 to 4 inches apart.

Consistent soil moisture is important for the best growth. Be prepared to water if rainfall is inadequate.

Harvest the roots of beets in six to eight weeks. Leafy tops are best used when they are just 4 to 6 inches tall.

Carrots are another root crop and a great vegetable to grow with kids. There are so many varieties to choose from including some with globe-shaped, short or long tapered roots.

Carrots grow best in deep, loose soil in full sun. Plant seeds just one-quarter inch deep. Thin seedlings to one inch apart as they emerge. As they continue to grow, thin them again to 2 to 3 inches apart.

Harvest carrots in about two months. Small carrots are the most tender.

Radishes are available in a wide range of colors and shapes. Some have a mild flavor; others have a strong flavor. There are round and elongated varieties. Radishes come in pink, white, purple and red.

Plant seeds in fine, loose soil. Radishes can also be sown in containers if you don't have enough space in the garden. As seedlings emerge - usually in just a week - thin them to the right spacing as indicated on the seed packet.

Radishes mature quickly and will be ready to be harvested in as little as three weeks.

Onions are most often grown from "sets" or small plants. Plant them about 1 inch deep and 4 inches apart if you want larger onions, 2 inches apart if you plan to eat them as green onions.

Start fertilizing three weeks after planting with a high nitrogen fertilizer and continue every two to three weeks until a month before harvest. Keep them well watered. Harvest larger onions when their stems fall over.

Peas are grown for their edible seeds or their pods. Plant peas an inch deep and an inch apart. Some varieties need to be trained on trellises; others do not.

Harvest garden peas, grown for their seeds, as soon as the seeds fill their pods. Harvest snow peas when seeds are just starting to form in their flat, edible pods. Wait until the seeds of sugar snap peas are full size in their edible pods before harvesting.

Potatoes require loose soil high in organic matter - they will not do well in heavy clay soils. Plant them 2 to 3 inches deep and 9 to 12 inches apart. When shoots emerge and as they grow, continue to hill soil around the plant.

Potatoes need consistent moisture and fertilizer high in phosphorus and potassium. Harvest potatoes two weeks after the vines have died.

Broccoli is most often grown from transplants. Space them 18 inches apart. Keep them well watered especially as heads are developing.

Fertilize with a high nitrogen fertilizer when plants are about 12 inches tall.

Harvest broccoli when the bud clusters are tight and before any flower buds open. Remove the central stem below the head. This will encourage side shoots and more heads to develop.

Cabbage is also most often planted from transplants. Space plants 12 to 18 inches apart in fertile well-drained soil. Ample, consistent moisture is especially important as heads are developing. Fertilize with a high nitrogen fertilizer when plants are half grown.

Harvest cabbage as heads form. Small heads may form on the stems left behind.

Kohlrabies are my favorite cool-season vegetable. Plant seeds one-quarter to one-half inch deep and a few inches apart. Keep the soil moist to prevent them from developing a woody center.

It is recommended to harvest kohlrabies when they are 2 to3 inches wide. I like to pick them when they are just less than 2 inches - what a sweet and tender treat!

•Diana Stoll is a horticulturalist and the retail manager at The Planter's Palette, 28W571 Roosevelt Road, Winfield, IL 60190. Call (630) 293-1040 or visit planterspalette.com.