How to Plant, Grow, and Care For Radicchio in Your Garden
Thinking of trying something different in your vegetable garden this season? Radicchio is a vegetable that you won't see in every vegetable garden you visit. But it's great taste and variety of uses has its popularity rising over the last several years. In this article, organic gardening expert Logan Hailey takes you through each step of how to plant, grow, and care for Radicchio.
With its stylish maroon, to pastel pink, to flecked creamy yellow leaves, radicchio might be one of the trendiest vegetables in the culinary world. It has a cult following in the Pacific Northwest, where annual radicchio festivals bring together chicory-enthusiast chefs, gardeners, and organic farmers to celebrate the “rad” winter vegetable. Yet most gardeners have never even heard of radicchio, let alone tried to grow it.
Radicchio is a cool-weather crop that can be planted in spring or fall, and held in the ground throughout winter in many regions. Its distinguished appearance adds splashes of burgundy and cream to the garden as well as the plate. Radicchio has an adapted flavor best complemented by balsamic vinegar, olive oil, and cheese.
If you’re looking for a specialty green to diversify your winter garden, radicchio is a beginner-friendly crop that sweetens with frost and is adaptable to a variety of conditions. Growing radicchio is no more difficult than growing lettuce, though it is far more elegant.
Let’s dig into how to plant, grow, and care for this unique Italian chicory!
Plant Type Perennial grown as an annual
Plant Family Asteraceae or Compositae
Plant Genus Cichorium
Plant Species intybus
Hardiness Zone USDA Zones 4-10
Planting Season Spring or Fall
Plant Maintenance Low to Moderate
Plant Height 4-6”
Fertility Needs Light
Temperature 50-75°F is ideal
Companion Plants Carrots, beets, lettuce, onion
Soil Type Well-drained, slightly acidic
Plant Spacing 8-10”
Watering Needs Low to Moderate (about 1” per week)
Sun Exposure Full sun to partial shade in summer
Days to Maturity 50-100, depending on variety
Diseases Root rot
Radicchio has been famous in Europe for centuries, yet just recently gaining popularity in American cuisine. Modern cultivation of this vibrant chicory started around the fifteenth century in the Veneto region of Italy.
However, radicchio’s chicory ancestors have been consumed since ancient Egyptian times. Renowned herbalist Pliny the Elder wrote of the medicinal properties of radicchio in the Naturalis Historia, praising it as a blood purifier and remedy for insomnia.
Often mistaken for red cabbage or purple lettuce, radicchio is a lightly bitter chicory that includes dozens of cultivars of the species Cichorium intybus. To the untrained eye, radicchio may look like a white-splashed cabbage, but in fact is not at all related to brassicas. It belongs to the Asteraceae family, along with dandelions, endive, artichoke, lettuce, burdock, sunflowers, and chamomile.
The plant is a perennial grown as an annual. Radicchio thrives in the Mediterranean climate of northern Italy, yet can also be grown in most climates in the United States. In general, frost sweetens the chicory while heat makes it more bitter. That being said, this is the type of vegetable that may leave you craving more bitter flavors.
While this chicory is finally making its way into the American foodie scene, it has been a delicacy in Italy for centuries. Most commonly known for its elegant, distinctive flavor in Italian dishes, radicchio is a chicory-family vegetable that has been consumed since ancient Egypt.
The bitter green is known to aid in digestion, ease insomnia, purify the blood, and provide high levels of vitamins B, C, and K. Best of all, it is easy to grow and adds a unique flavor to a variety of dishes, from soups and salads to risotto, pizza, or cheese platters.
While American tastebuds tend to prefer sweet and salty flavors, radicchio awakens ancient bitter receptors in our tongues called T2Rs that stimulate digestion and regulate appetite. Because of this digestive benefit, European cuisine often includes bitter greens like radicchio and endive in appetizers, along with aperitif and digestif cocktails such as vermouth and amaro to aid in digestion of meals.
Radicchio is markedly Italian, with cultivars named for specific geographic regions of Italy where they originated. This includes Chiogga, Verona, Treviso, and Veneto. Radicchio specifically originated in northeastern Italy where farmers and gardeners sought to cultivate a nutritious, crunchy green during the winter.
The most common type of radicchio found in the United States is the Chiogga type: a soft-ball sized variety with a tight round head, dark purple-burgundy leaves, and cream-colored ribs. Radicchio di Chioggia is the most mild of the radicchios, bred in the 1930s for easier cultivation and a deeper purple color. It originated in the town of Chioggia in northern Italy and is pronounced “kee-OH-gee-uh”.
Radicchio is most commonly grown from seed. There are also vegetative regrowth methods of radicchio including “forcing” the chicory roots to regrow in the darkness of winter. Most gardeners will opt for the simple seed-growth variety, whereas chicory enthusiasts may want to try out “forcing” for a unique challenge and ultra tender flavor experience.
Finding Radicchio Seeds
Italian immigrants first brought radicchio seeds to regions of California for commercial cultivation in the 1980s. Since then, plant breeders and specialty seed companies have made several varieties widely available in the U.S. Seed packets may be a bit more expensive or rare than other leafy vegetables, but the reward for growing this culinary delight is well worth it.
Finding the right radicchio varieties can be confusing thanks to the traditional Italian names and diversity of strains adapted to certain locations. We’ll cover the best types and varieties below, but suffice to say that radicchio seeds can be found in most seed catalogues, particularly smaller organic seed companies dedicated to your specific region. A few of my favorites include:
Midwest: Baker Creek Rare Seeds
South: Southern Exposure Seeds
Radicchio is a cold hardy chicory and that can be planted as early as the soil can be worked. You can sow seeds every 3 weeks for a continuous supply throughout the cool seasons. While transplanting is most common, you can direct-seed in the garden in early spring when soil temperatures are between 40° and 70°F. Use a soil thermometer to check the garden bed temperature before seeding.
Directly sown seeds should be about 1” apart in rows 12-18” apart. Cover seed lightly with 1/8” inch soil and gently tamp it down so it doesn’t blow away. Keep consistently moist and cool, using row cover over the top to encourage even germination. Thin to 8” apart and transplant the thinnings if you’d like.
Radicchio seeds enter thermal dormancy when exposed to temperatures above 77°F, so this crop is most commonly grown in the cool seasons of spring, fall, and winter. Optimum germination is a soil temperature around 60-68°F.
If starting indoors, sow seeds in flats or plug trays 3-4 weeks before planting outdoors. The seeds are very small and should be barely covered with fine vermiculite. If sowing in open flats, be sure that each seedling has at least 2” of space and is properly thinned to avoid crowding.
Once seedlings have established a few pairs of true leaves, you can harden them off by reducing water and temperatures 2-3 days before planting outdoors. If seedlings are properly hardened off, they can survive temperatures down to 20°F, perfect for early spring or late fall plantings.
Forcing means digging up the plant in the fall, cutting off the head, and replanting radicchio indoors in peat moss or water. It is covered with a pail or placed in a basement to sprout without light. The regrowth from the chicory root creates a tender bittersweet blanched radicchio like the famed Treviso Tardivo or Rossa di Verona varieties.
If you want to “force” your radicchio, you must begin with established plants that you have seeded and grown in the garden. Use a shovel to dig up the entire plant, including the long taproots. You can cut off the heads at the base and eat them, or peel back all the older outer leaves and keep the core intact.
Prune the roots back to 6-10” and plant in a pot of peat moss or a shallow water trough. The forcing container should be shielded from light and will produce new tender blanched chicory sprouts in 15 to 25 days.
Once you have grown and hardened off or purchased your radicchio seedlings, planting is a breeze. These chicories are super cold hardy (down to 20°F) and can be planted out with the earliest garden vegetables like spinach, radish, and beets.
Cool-weather spring plantings will establish slower, but be ready before the heat of spring. Late spring warm-weather plantings will mature 1-2 weeks faster, but may be less tender and ideally enjoy cool nights below 60°F.
I’ve found that late summer and early fall plantings are my favorite in terms of flavor and performance. Southern regions can grow radicchio throughout the winter.
Grasp your radicchio seedlings at the base and gently wiggle the root plug out of its container. Use a hori hori knife or planting trowel to create a shallow hole and place the seedling inside. Radicchio should be transplanted shallowly, ensuring that the base of the plant is slightly above the soil to discourage rotting at the base but the roots are still covered.
Transplant 8-10” apart in rows 18” apart, depending on variety. Provide plenty of water at the time of transplanting, but be sure that the soil is well-drained so that roots are not sitting in a puddle.
Growing radicchio is a lot like growing lettuce, except they take 2-4 weeks longer to form full heads. It is a hardy, easygoing plant that enjoys the cool shoulder seasons before or after the standard garden stars like tomatoes and peppers come to harvest.
Radicchio prefers full sun in the spring and winter, but it enjoys some afternoon shade if grown during warm summer months.
If you are forcing radicchio indoors during the winter, try to do so in a closet or the darkest place possible. Traditionally, forcing is done in a root cellar or basement to encourage premium blanching (whitening) of the stalks.
The bittersweet crisp flavor of radicchio can be very delicious, however overly stressed plants can become too bitter to enjoy. Water stress and drought will create exceptionally bitter plants. To avoid this, provide radicchio with about 1 inch of water per week. Often this means using drip irrigation or soaker hoses 2-3 times per week. Radicchio is fairly drought tolerant and should not be overwatered, as it is prone to rot.
Like most garden vegetables, chicories do best in well-drained soils with plenty of compost or organic matter. The ideal pH is between 5.5 and 6.5. I prefer amending the garden with 2-3” of high quality organic compost before planting. Loosening the soil with a broadfork or digging fork can improve drainage to further help prevent root rot. A thin mulch of chipped leaves is also ideal for retaining moisture and keeping radicchio roots cool, although mulch is not traditionally used in chicory cultivation.
Radicchio is a cool-weather crop that especially thrives in spring and fall, or winter in southern regions. However, too much cold when plants are young (and not yet hardened off) can lead to bolting. Long, hot days of summer can also cause premature bolting.
Once established, radicchio tolerates fall frosts very well and gets sweeter in the cold. Growth slows significantly in cool temperatures, so it is best to establish radicchio in late summer or early fall in order to reach full head maturity before deep winter freezes.
Ideal ambient temperatures for germination are between 68° and 75°F. Soil temperatures should be 60-68°F for even germination. Once established, ideal temperatures for growth and maturity are 60-65°F. If you are growing in a hot climate or during the summer season, it is important to plant radicchio in an area with afternoon shade.
Cold nights are especially favorable for this crop, which is what makes it so popular in the northwest and northeast. Fluctuations in daytime highs and nighttime lows during the final month of radicchio growth are said to create the most solid heads and bright burgundy color.
A small dose of liquid seaweed or fish fertilizer is the best way to feed young radicchio plants, beginning a week or two after emergence. However, not much fertilizer is required to grow this delicious green. Radicchio is a light feeder and will actually become bitter or bolt if it is provided with too much nitrogen.
Radicchio is a low-maintenance crop that is pretty hands-off once planted. If you use row cover to germinate your seeds, it is recommended to remove it as soon as possible. Row cover typically buffers against temperature extremes, but in the case of radicchio, it needs the temperature fluctuations to yield the best heads.
You can begin harvesting radicchio about 6-10 weeks after transplanting. Regularly check the plant’s density to gauge when it is mature. The heads should be somewhat firm, like a butterhead or iceberg lettuce. Once they begin to firm, they will not get any bigger and may bolt if you wait too long to harvest. In the fall, heads hold much longer in the field and can be harvested as needed.
Use a sharp knife to cut the base of the head, just as you would a lettuce or cabbage. Morning harvests are best while the plants are still cool. Chill the heads right away and refrigerate in a breathable bag for 3-4 weeks.
Because modern radicchio varieties are still being improved, they are not always predictable or completely uniform. Certain varieties are bred for specific seasons and regions. I recommend trialing several varieties in your garden to see what performs best in your conditions.
There is no risk of cross pollination because radicchio is harvested before it ever flowers, so feel free to plant a rainbow medley of cultivars and taste the diversity.
These are the most common red-cabbage-looking radicchios found in American grocery stores. However, those bland supermarket heads could never compare to the crisp, savory, bitter deliciousness of garden grown Chioggias.
- ‘Indigo’: This hybrid is the most reliable Chioggia-type variety in both hot and cold weather trials. Heads are firm and 4-5” in diameter with a beautiful burgundy color and good flavor. High yield potential for summer plantings and 65 days to maturity.
- ‘Leonardo’: A uniform, slow-bolting Chioggia-type that produces extra dense 4-5” heads. A brighter purple color and better flavor results from cool fall plantings. It takes 65 days to mature and is highly resistant to bolting.
- ‘Perseo’: This extra-early Chioggia-type yields small round heads about 3-4” in diameter. Great for small gardens and high density plantings. Matures in just 55 days.
- ‘Palla Rossa’: An Italian favorite with dense magenta heads. This Chioggia can be harvested over a longer window and takes 90 days to mature.
If Chioggia types were the ambassadors of new wave radicchio popularity in the US, Rosa di Veneto would probably be the second wave of popularity. Their sumptuous pretty pink looks make them popular subjects of social media foodie photos and their flavor does not disappoint. In the garden, they are very cold hardy and peak in late November through February.
- ‘Rosato’: Salmon-colored to bright pink heads are stunning in salads, but lose their bright color in cooking. The leaves are substantial and heads resemble a gorgeous rose. ‘Rosato’ takes 120-130 days to mature and seed is grown in Italy by Smarties.Bio.
A taller, football-shaped radicchio, Treviso types hail from the Treviso region of Italy (another epicenter of chicory production). They are the least bitter and most sweet of all radicchio types. The term ”precoce” means early and is used to differentiate these radicchios from the late fall “tardivo” radicchio that is “forced” to maturity indoors.
- ‘Regina Rossa’: At 90 days to mature, this unfussy elongated Treviso-type has the mildest bitterness and is very popular in raw salad preparations. The sweetness of the deep red leaves compliments the slight bitterness of the white midrib. Be sure to plant early for successful spring crops.
- ‘Pacifico’: Another part of Uprising Seed’s Gusto Italiano Project, ‘Pacifico’ is a later maturing cultivar that takes about 110 days to harvest. Best planted around the summer solstice, this delicious maroon-red Treviso-type is ready to harvest just as the cool weather of fall sets in in most regions.
- ‘Bel Fiore’: This gorgeous open-pollinated speckled type is green on the outside and creamy yellow on the interior with white ribs and pinkish-red flecks throughout. The habit is looser like a butterhead lettuce. Translated to “beautiful flower” in Italian, ‘Bel Fiore’ has an open center like a flower when in the ground. Heads mature over a 2-3 week period and take 52 days from planting.
- ‘Delta’: A collaboration between Italian breeders Sparties.Bio, Uprising Seeds, and the Culinary Breeding Network, this gorgeous buttery yellow radicchio has wine red flecking on the leaves. Its bitterness is very mild and the crisp crunchy texture is more like a lettuce leaf. Delicious shredded in salads or grilled in wedges with a drizzle of balsamic and sprinkle of cheese. 90 days to mature.
Thanks to their bitter flavor, chicories are largely resistant to bugs. I have never had a pest problem with my radicchio plants (knock on wood!). They are, however, susceptible to root rot in dense clay soils or excessively wet conditions.
Root rot can be caused by a variety of fungal pathogens, but is easily prevented by properly preparing soil to ensure good drainage and no water-logging. Avoid over irrigating radicchio or planting in heavy clay. Once roots begin to rot, it is difficult to reverse. You can simply harvest the heads and use in salads.
Radicchio is traditionally prepared raw in salads, grilled in wedges, or cooked in soups, risotto, pasta, and pizza. It tastes best with acidic ingredients like balsamic vinegar and creamy cheeses. My favorite radicchio salad is simply thinly shredding the burgundy leaves, dressing with olive oil and vinegar, and covering with Feta or goat cheese. Radicchio is also delicious with pieces of aged gouda rolled up in its leaves as a snack.
Medicinally, chicory roots and leaves have been used as digestive bitters and liver tonics for thousands of years. You can often find chicory root in inulin digestive supplements as well as coffee substitutes.
Frequently Asked Questions
Is radicchio easy to grow?
Growing radicchio is very similar to growing lettuce, except it takes longer to mature. Plant in the early spring or late summer to mature radicchio in cool weather for the best flavor and performance.
How long does radicchio take to grow?
Radicchio varieties can take 50-100 days to mature, depending on the cultivar, seasonality, and conditions. Cooler weather slows growth and extends the harvest window.
How do you harvest radicchio so it keeps growing?
Radicchio will regrow quickly by harvesting only the outer leaves as needed. You can also cut the head above the base and irrigate the plant to encourage it to re-sprout. Radicchio is also “forced” by harvesting whole plants, trimming the roots, and growing in water or peat moss in dark conditions indoors.
When should radicchio be planted?
Radicchio is best planted very early in the spring or around the summer solstice for fall crops. Hardened seedlings are hardy down to 20°F and temperature fluctuations actually create the best flavored heads.
If you’ve never tried this Italian delicacy, I recommend testing a traditional radicchio dish at an Italian restaurant. If you are intrigued, try growing it in the garden next spring or fall. Radicchio is remarkably easy to grow and resilient in a variety of conditions. You can diversify your winter harvests and your flavor palette with this unique bitter vegetable.