By Matt Gibson
Broccoli Raab, also known as broccoli rabe, rapini, rapa, rappone, asparago (in Italy), Chinese flowering cabbage, turnip broccoli, Italian mustard, broccoletto, taitcat, and rape, is actually not a type of broccoli. Broccoli raab, which is pronounced like the name Rob, is actually more closely related to turnips and mustard greens.
Like turnips and mustards, broccoli raab has a nutty, pungent, and slightly bitter taste. Broccoletto is a green cruciferous vegetable which is similar to kale with several slender shoots and small loose bud clusters that are similar to broccoli at the top of each shoot. It is cultivated around the world for culinary use but is especially popular in Italian, Portuguese, and Galician cuisines.
Broccoli raab is a fast-growing cool weather plant that is typically ready for harvest in just 45 days, depending on the variety. It is highly nutritious and packed with antioxidants, as well as iron, calcium, potassium, and vitamins C, K, and A. Research conducted at John Hopkins Medical Center shows that rapini has 30 times the concentration of anticancer substances than are present in broccoli. Broccoli raab deserves a spot in every vegetable garden due to its nutritional value, and how quick and easy it is to grow.
Varieties of Broccoli Raab
There are many varieties of broccoli raab, but only a handful of them are commercially available to gardeners via seed packs. Cornell University lists 21 different varieties that are actively cultivated around the world. We put together a list containing 12 of the most popular and highly acclaimed cultivars of broccoli raab to choose from when selecting seeds for your vegetable garden. The first three in our list are our recommended varieties.
Spring Raab – The Spring Raab cultivar got its name due it being especially good for spring sowing, though it can also be planted in the winter for an early spring harvest. It is fairly bolt-resistant and fast-growing, maturing in just 40 to 45 days. Also called Spring Rapini.
Zamboni – This Italian heirloom variety matures in 45 to 70 days producing uniform plants with tender little leaves. The leaves surround its large bud clusters that sprout atop tall, straight blue-green stalks. Zamboni is coveted by gardeners due to its tendency to produce generous yields of buds and side shoots.
Super Rapini – This cultivar is an early Italian heirloom that matures in 60 days. It matures quickly and proficiently, all at one time. Multiple plantings are suggested. Thin well or it tends to flower before producing a good amount of leaves. Seedlings are susceptible to being eaten by flea beetles, so consider covering with row covers..
Sessantina – The Sessantina cultivar is incredibly fast-growing, reaching maturity in as little as 30-35 days. The 12 to 14 inch plants make big buds on tall, tender stems. Can be grown nearly year-round and harvested anytime except for during the summer months. Also known as Sessantina Grossa
Early Fall Rapini – Though more heat tolerant than the spring varieties, the Early Fall Rapini prefers a cooler, short-day season. This cultivar is typically planted in late August or September for a mid-October harvest. Maturing in 45-55 days and growing to 18 to 24 inches tall, the Early Fall Rapini tends to bolt early.
Quarantina – Also known as Cima di Rapa Quarantina, this Italian broccoli raab variety produces small, early plants that grow to just eight to ten inches tall. Well suited as a fall crop due to its heat tolerance. Matures in 28 to 45 days.
Spigariello Liscia – Maturing in 45 to 70 days, this variety is grown like a typical broccoli raab but is actually a leaf broccoli. After 70 days, it will form small heads similar to miniature broccoli crowns. Harvest entire plants for bunching, or take a few leaves at a time for a cut and come again harvest.
Sorrento – Cultivated for spring harvests, Sorrento is another early variety that matures in 55 days. The plants grow taller than the typical raab plant, reaching about 30 inches by harvest time, with dime-sized florets (large for raab plants) and blue-green leaves that sprout atop well-branched plants. Very similar to its relative, the mustard plant.
Hon Tsai Tai – Reaching maturity in just 37 days, this Asian green is best when planted between June and October and harvested between midsummer and early winter. Young plants tend to branch and produce long, narrow, red-purple flower stems with small mild mustard flavored florets.
Spigariello – Also known as Cavolo Broccolo Spigariello, this Italian variety matures in 45 days. The leaf broccoli plant is grown more for its smooth, tasty foliage than its tiny buds.
Novantina – Maturing in 55 days, this variety produces large, 14 to 18 inch tall broccoli raab plants with wide stems and massive leaves. Can be grown in the Spring, Summer, and Fall. This Italian heirloom is also known as Di Rapa Novantina.
Growing Conditions for Broccoli Raab
Broccoli Raab prefers full sun exposure for best production and health but will tolerate partial shade. Raab enjoys a soil with a pH between 6.5 and 7.5 and a soil temperature between 60 and 65 degrees. Amend soil with plenty of well rotted compost prior to planting. Plant in well draining soil and supply an even and moderate amount of water throughout the growing season.
Plant broccoli raab to mature during cool weather conditions. In milder climate areas, plant in the late summer, fall, or winter for harvesting in winter or early spring. In colder regions, set young plants out two to four weeks prior to the last frost date in your area. As long as the plants are established, they will resist light frosts, but will die out from exposure to hard freezes. Use a frost blanket or a plastic tunnel to protect your broccoli raab plants from cold fronts.
How to Plant Broccoli Raab
Broccoli raab is a cool season plant that can be sown in average, well-draining soil as soon as the soil is workable. Good companion plants for broccoli raab include spinach, carrot, bush bean, beet, tomato, cucumber, onion, lettuce, chard, celery, and potato. Do not plant next to pole beans or snap peas. When rotating crops, avoid following broccoli raab with other members of the cabbage family.
If growing broccoli raab from seed, start your seeds indoors six to eight weeks before the last expected frost date in your area. If temperatures are kept at 75 degrees F, you can expect germination in about six days. Seeds can also be sown directly in the garden in the late spring or early summer for fall harvests.
If growing broccoli raab from seedlings, take extra care when transplanting so as not to disturb the seedling’s fragile root systems. Transplant young plants when they become three inches high, setting them into the soil about one inch deeper than they were placed inside their pots. Space the plants in a staggered pattern in beds 16 inches apart in rows spaced one foot apart. You should be able to fit three rows into a single bed that is 36 inches wide or more.
Care for Broccoli Raab
Weeds need to be controlled near broccoli raab plants, as they will compete with your crops for water, space, and nutrients. Be careful not to disturb the roots or the soil around your plants too much when weeding. Laying out a two inch layer of organic mulch will help to deter weeds and save you some effort with weeding throughout the season.
Keep your raab plants well watered throughout the season, especially during dry periods. Raab is a heavy nitrogen feeder and, like all cabbage family members, it uses significant amounts of boron. To supply the nitrogen, fertilize your raab plants every two or three weeks using an organic fertilizer, such as fish emulsion, diluted to half strength. To keep your soil rich in boron, amend it well before planting with plenty of rotted manure or compost. If there is not enough organic matter in the soil in your beds, it will likely be deficient in boron, which will stunt the growth of your broccoli raab plants.
One month after planting your broccoli raab plants, be sure to pinch off the first stem that produces a bud as soon as you notice it. This will encourage the plant to develop more than one dozen side shoots for a more prolific harvest.
Garden Pests and Diseases of Broccoli Raab
Broccoli raab can have issues with several insects and pests. Small insects such as aphids can be removed from your raab plants by blasting them with a spray of water from your garden hose, however, you may need to do this several times over the course of a few days in order to knock them all off. Larger pests, such as cabbage worms can be removed from the plant by hand and crushed. Row covers will protect your plants from flea beetles, which are especially known to feed on the seedlings and younger broccoli raab plants.
You will notice aphids on your plant which appear in colonies of tiny gray-green insects on leaves and cause deformed and curled leaves, leaving behind a sticky honeydew residue on the surface and underside of the foliage. If spraying the plant down with water doesn’t take care of the issue, insecticidal soap spray should do the trick.
The diamondback moth caterpillar is another potential issue for broccoli raab plants, especially if weeds are allowed to grow in your garden beds. This pest can be identified by small holes in the leaves and small, loose cocoons, about one-third-inch in length on the leaves. If you notice signs of the diamondback moth caterpillar, lay out BT (bacillus thuringiensis) around the affected plants. Additionally, pull up any weeds in your beds and lay out a two inch layer of mulch to prevent future problems.
Inefficient watering techniques can lead to broccoli raab head splitting. To avoid this issue, do not allow the soil to become too dry. If the soil does get too dry, don’t make up for it by overwatering. Instead begin applying water immediately, but in small amounts, so as not to shock the plant, causing head splitting. Apply small doses of water frequently until beds are evenly moist. Then resume a regular watering schedule.
How to Harvest Broccoli Raab
As broccoli raab matures, shoots will start emerging from the crown of the plant. Once the shoots have reached one foot high, you may begin harvesting the buds and leaves that grow around the buds. Timing is essential when harvesting raab plants, as the buds can open overnight if not harvested in time. Harvest your plants before the buds open by cutting them down to ground level or where the stem becomes soft to the touch. Harvest your plants when they reach a height between 10 and 15 inches. If you harvest your plants carefully, leaving two leaves still attached, they will likely re-sprout for several more harvests. Regular harvesting will promote continued growth.
How to Store Broccoli Raab
Just after harvesting, store your unwashed raab harvest in a plastic bag in the refrigerator. Properly stored broccoli raab should keep for five days. You can also blanch and freeze your raab harvest to use throughout the year.