How to Grow Radicchio in Your Home Vegetable Garden

Radicchio (Cichorium intybus) is a hardy perennial crop and a great choice for those looking for a cool-weather vegetable to add to their garden.

1. 1. Choose a planting time based on your climate zone. In cold weather climates, direct seed radicchio in early spring two to three weeks before the last frost for a late summer harvest. In warmer regions, sow seeds in late summer for either a fall harvest or an early winter harvest. Depending on the specific cultivar, radicchio typically takes 65 to 90 days to mature.
2. 2. Pick a sunny area. Radicchio thrives in a full sun environment, but a partial shade location is acceptable if you're planting in the late summer for a winter or fall crop; the shade will help cool down your seedlings during the warmer summer temperatures.
3. 3. Plant sees in loose, well-drained soil. Make sure your garden has fertile, loamy soil with a pH level between 6.5 and 8.0.
4. 4. Enrich your soil with nutrients. Before planting your radicchio, improve your soil quality by mixing in organic matter like aged compost or manure.
5. 5. Give seeds enough space. Sow seeds a quarter of an inch deep and eight to 12 inches apart. There should be 15 to 18 inches of space between each row. Your radicchio seeds should germinate within one to two weeks.

After your radicchio seedlings have sprouted, make sure you tend to your radicchio until harvest.

• Keep your soil moist but not oversaturated. Radicchio needs consistent water during its growing season; one to one-and-a-half inches of water per week is ideal. A drip irrigation system is best because the low-pressure flow doesn’t disturb the soil and it delivers water at ground level, which prevents leaves from getting wet and contracting diseases.
• Add a two- to three-inch layer of organic mulch. Mulching suppresses weeds and helps lock in moisture, keeping the soil temperature cool.
• Fertilize after four weeks. Use a small dose of nitrogen-based fertilizer to boost growth. Be careful to keep the dose low, as too much nitrogen can cause your radicchio to bolt and develop a more bitter taste.
• Monitor for diseases. Radicchio plants are susceptible to diseases like black rot, downy mildew, bacterial leaf spot, and Alternaria leaf spot. To prevent these maladies from harming your radicchio, make sure to avoid getting the leaves wet, provide good air circulation, and keep your garden free of weeds. If your plants do get infected, immediately remove any contaminated leaves, and use a copper-based pesticide, if necessary.
• Keep an eye out for pests. Common garden pests like aphids, cabbage loopers, slugs, and leafminers are some of the insects that may plague your radicchio plants. You can control aphids and leafminers by using insecticidal soap. Pick cabbage loopers off your plants by hand, and consider adding a floating row cover to prevent the loopers from laying more eggs. To deter slugs, try placing coffee grounds around your plants.

When harvesting radicchio, you have the option to harvest the entire head or only take the leaves as you need them. Either way, make sure you follow these harvesting guidelines so that you end up with the best-quality radicchio for your culinary needs.

• When to harvest: You can harvest radicchio leaves after five to six weeks, but if you’re planning to harvest the mature radicchio head, you’ll need to wait nine to 13 weeks, depending on the variety. Feel the head and make sure it's firm before harvesting. If you wait too long and your radicchio crop becomes over-mature, it will have a stronger bitter flavor and an unappetizing tough texture.
• How to harvest: If you’re only harvesting the leaves, you can cut or break off the radicchio leaves one at a time. If you’re harvesting the entire head, use a knife to cut the head off from the roots right above ground level.
• How to store: Place radicchio in a perforated plastic bag in your refrigerator. It will keep for three to four weeks.

If you're looking to spice up your salad greens, try mixing raw radicchio leaves with Belgian endive, hazelnuts, and a sweet dressing of your choice to counteract the bitter flavor. Outside of a salad, try sautéing your radicchio with olive oil and salt for a delicious snack or side dish.

Grow your own food with Ron Finley, the self-described "Gangster Gardener." Get the MasterClass Annual Membership and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community - and the world - a better place.