Broccoli raab, also known as broccoli rabe or rapini, is an easy-to-grow and enjoyable addition to any vegetable garden. More closely related to the turnip than the broccoli, this plant was most likely cultivated from a wild herb originating in the Mediterranean and China. Broccoli raab has two harvest seasons, one in early spring and one in late fall, and can overwinter in milder climates. With its abundant nutrition and complex flavor, broccoli raab is a must-have cool weather crop.
Spring broccoli raab is a leafy plant that grows to about 30″ tall with asparagus-like shoots and turnip-style leaves. It prefers a warmer growing season with long days and is best suited for planting in the spring. This type is quick to mature.
Seed Depth: 1/4″
Space Between Plants: Start seeds 1″ apart, thin to 4–6″.
Space Between Rows: 18–14″
Germination Soil Temperature: 50–85°F. Optimal 60–65°F.
Days for Germination: 7–14
Sow Indoors: 3 to 4 weeks before average last frost.
Sow Outdoors: 4 to 6 weeks before average last frost or as soon as soil can be worked. Also, sow in late summer for fall harvest, or early fall for overwintering in warmer climates.
Vegetative: Possible but not recommended.
Grows best in cool weather, as hot temperatures will cause it to bolt. While plants ideally prefer a temperature range of 40-75°F, they can withstand temperatures as low as 25°F. Like most vegetables in the brassica family, they do not do extremely well in tropical or humid environments.
Natural: Full sun. Tolerates partial shade but will slow in maturity.
Artificial: Grows well under fluorescent or LED lamps. Needs at least 6 hours light per day.
Soil: Prefers a nutrient rich, well-drained soil with slightly acidic pH levels.
Soilless: Will grow in most soilless media, including coco coir and well-rotted manure.
Hydroponics: Thrives in a variety of hydroponic systems.
Aeroponics: Thrives in aeroponic systems.
Water: Requires moderate levels of water. Aim for watering 1–2 times per week. In hot weather, increase watering to avoid wilting.
Nutrients: Requires high levels of nutrients. Broccoli raab needs lots of nitrogen and boron, so add compost or compost tea for a nutrient-boost. If transplanting, incorporate manure or compost into the top several inches of soil where many of the feeder roots are located.
Foliar: Try an organic nutrient spray such as liquid seaweed or fish emulsion.
Pruning: Trim damaged or diseased leaves to promote new growth.
Mulching: Use mulch to maintain soil moisture and suppress weeds.
Deficiency(s): A boron deficiency will cause plants to develop hollow stems. Add compost or spray with compost tea to amend.
Rotation: A 1- to 3-year rotation away from all members of the brassica family is recommended. At the end of the growing season, remove the entire plant, including the root system.
Companions: Grows well with members of the nightshade family, as well as cucumber, beet, carrot, and spinach. Avoid snap and pole beans.
Harvest: Plan to harvest in late spring or early fall in most climates, or early spring if overwintering. For greens, harvest leaves and stems by cutting to the ground before signs of flower stalk formation. For florets, cut after shoots form but before buds open.
Storage: Can be refrigerated for up to a week in a plastic bag. Once frozen, it will store well for several months.
History: Broccoli raab was brought to America by Italian farmers in the early 1920s. It’s thought to have descended from a wild plant related to the turnip that originated in either China or the Mediterranean region.
Preserve: Can be blanched and frozen for later consumption.
Prepare: Broccoli raab has a sharp, nutty, slightly bitter flavor, and blanching can tone this down. Sauté in olive oil with garlic and other spices of your choice for a tantalizing side dish.
Nutritional: Provides vitamin(s) K, C, A, calcium, potassium, iron, zinc, potassium, and riboflavin. It’s also rich in antioxidants.
Medicinal: Broccoli raab is currently being investigated for its anti-cancer properties. It contains phytochemicals proven to prevent cellular damage from free radicals. Its high vitamin K content implies bone strengthening properties. It also contains sulfur and other compounds that are known to aid in detoxification of the liver.
This Broccoli Rabe with Walnut Pesto, Red Chili Flakes, and Lemon recipe will give your taste buds a ride!