Brassica

( BRASS - ih - kuh )

At-A-Glance Information

This popularly cultivated genus includes crops known commonly as Cabbage, Broccoli, Kale, Bok Choy, Mustard, Turnip, and Mizuna. As a group, they are known as Cole Crops or Brassicas. Species are native to Western Europe, the Mediterranean, and temperate regions of Asia. There are also many species that have escaped cultivation to grow as weeds, especially in North and South America and Australia. Grow these plants in mixed beds or borders, in containers, or as members of vegetable gardens.

Brassica Species and Varietals

The genus Brassica is the type genus member of the plant family Brassicaceae, and includes 42 species. Brassica plants can grow in any zone. To find your zone, click here: Zone Map.

Brassica carinata (Ethiopian Rape, Ethiopian Mustard, Abyssinian Cabbage, African Cabbage, Ethiopian Kale, Mustard Collard)
This species is thought to be a natural hybrid between Brassica nigra and Brassica oleracea, and produces edible leaves with mild flavor. It is sometimes cultivated as an oilseed crop. Variety 'Texsel' is the most commonly grown. The yellow flowers will attract bees. Plants in this species reach up to 3.3-6 feet tall when mature and in bloom.

Brassica elongata (Elongated Mustard, Long-Stalked Rape)
This species is native to parts of Central and Eastern Europe, the Balkan Peninsula, the Caucasus, Morocco, and Central Asia. It has become naturalized in many other areas of the globe, where it is often found as a roadside weed. Leaves are consumed, and have a higher count of fatty acids than other species. These plants are considered invasive in many parts of the world, including southern Africa, Australia, and North America (Nevada, Utah, Colorado, and Oregon).

Brassica fruticulosa (Mediterranean Cabbage, Twiggy Turnip)
This agriculturally significant species was first described by Domenico Maria Leone Cirillo in 1792. It produces grey to green leaves, and is considered a wild cabbage. This species is considered invasive in Australia, Mexico and North America (California).

Brassica juncea (Mustard Greens, Brown Mustard, Chinese Mustard, Indian Mustard, Korean Green Mustard, Leaf Mustard, Oriental Mustard, Vegetable Mustard)
This species has many cultivars, divided into subgroups based on their genetic profile. Sometimes, these plants are grown as green manure or cover crops, but for the most part, cultivars are grown in vegetable gardens. These plants are considered invasive in many areas, including pars of the Americas, Australia, New Zealand, and Japan. Cultivars are listed and described below:

Canola
(Oil-Seed Mustard, Raya)
These plants are cultivated for their seeds, which are processed into oil.

Curled Leaf Mustard
(Curled Mustard, American Mustard, Texas Mustard)
Plants reach 10 inches tall, and leaves are large with curled edges. They are bright green with mild flavor.

Cut-Leaf Mustard
(Mizuna, Spider Mustard, Japanese Mustard Greens)
This variety produces dark green, finely cut leaves. Mild peppery flavor, great for stir-fries, soups, and salads.

Head Mustard
Typically used in picked form or stir-fried. Choice varietals include 'Swatow', Heart Mustard Cabbage, Wrapped Mustard Cabbage, and 'Bamboo'.

Horned Mustard
This variety produces leaves that have a horn at the center of the stem, hence the common name.

Japanese Giant Red Mustard (Takana)
With purple-green foliage with strong, sharp peppery taste.

Korean Red Mustard
These plants produce foliage that is deep purple-red with green petioles.

Large-Petiole Mustard
These plants produce large, edible leaf stems. They reach up to 30 inches tall.

Root Mustard
(Turnip-Root Mustard, Erdaomei)
This variety is cultivated for its underground roots, which are typically roasted, steamed, or stir-fried.

Snow Mustard
(Xuelihong, Red-in-Snow)
Hot when raw, balanced when cooked. Grows vigorously through the winter months.

Stem Mustard
(Swollen Stem Mustard)
This plant has knobby, fist-sized swollen green stems.

Brassica napus (Rape, Oilseed Rape, Canola, Colza, Neep)
This species is cultivated for its seeds, which are processed into the product called Rapeseed Oil. Plants reach about 40 inches tall when mature, with bright yellow flowers. Seed pods emerge green and mature to brown, before drying out and releasing their seeds. Canola is considered an invasive species in the Americas, Australia, and Europe.

Brassica oleracea (Wild Cabbage)
This species is native to the Eastern Mediterranean, and has many commonly cultivated varieties and hybrids, including those listed below. The true species produces green leaves that are fleshy and thick, allowing the plant to survive in drought conditions well. These biennial plants produce foliage in their first year and flowers in their second. These plants can be considered invasive in some regions, including North America, South Africa, and Australia.

Broccoflower
(Green Cauliflower)
This cultivar produces light green flowering heads, similar to Romanesco but with a more flattened head.

Broccoli
This variety is cultivated for its large flowering heads, stalks, and leaves, all consumed as vegetables. 'Calabrese' is the most commonly grown type.

Broccolini
This hybrid, commonly called Aspabroc, Baby Broccoli, or Tenderstem Broccoli, produces small florets atop thin stalks.

Brussels Sprout
This cabbage cultivar resembles miniature cabbages, which are produced along the length of stems.

Cauliflower
These annuals produce broccoli-like heads of flower buds, which are consumed as a vegetable. There are white, orange, purple, and green types.

Caulini
Similar to Broccolini, these plants produce long stems topped with small florets that are typically white in color.

Collard Greens
These loose-leafed plants are grown as food crops and produce dark green leaves that are cooked and eaten as vegetables.

Cone Cabbage (Hispi)
Also called Pointed Cabbage, this varietal is cultivated for its tapering flowering heads, with a less pronounced taste than common cabbage.

Gai Lan
(Kai-Lan, Chinese Kale)
These plants are cultivated for their leafy greens, which have a strong, slightly bitter broccoli flavor.

Jersey Cabbage
These plants develop very tall stalks (6-10 feet tall) that are harvested and used as walking sticks. Fodder plant.

Kale (Leaf Cabbage)
This cultivar is grown for its edible, tough purple or green leaves. Stems can be white or red, and are tough even when cooked. There are many types of Kale.

Kalette (Kale Sprouts)
These plants are a cross between Kale and Brussels Sprouts, and produce 2-inch florets.

Kohlrabi (German Turnip)
This cultivar can be eaten raw or cooked, and is harvested for its enlarged stem. Stems can be white or purple-red, though edible parts are always white.

Lacinato Kale (Tuscan Kale)
These plants reach between 2 and 3 feet tall, and produce dark blue-green edible leaves. It is an ingredient of traditional Minestrone soup.

Ornamental Kale
This species produces Kale-like foliage, but leaves are unpalatable. Instead, these plants are grown as ornamentals.

Red Cabbage (Blaukraut)
Leaves of this variety are dark purple, and are used fresh or cooked in many cuisines.

Romanesco
These flowering heads have a nutty flavor and firmer texture than broccoli or cauliflower when cooked.

Savoy Cabbage
This popularly-cultivated plant has crinkled foliage. Popular varieties include 'Winter King', 'Tundra', and 'Savoy King'.

Smooth-Leaved Cabbage
This variety is commonly harvested for its large heads of smooth green leaves.

Brassica rapa (Turnip, Field Mustard, Bok Choy, Napa Cabbage, Bird's Rape, Chinese Cabbage, Rapini)
This species has many widely grown cultivars, and its true origin is difficult to pinpoint due to its long history. Plants typically produce rosettes of green foliage, and are cooked or eaten raw after harvesting. These plants can be considered invasive in some regions of the world, including the Americas and Oceania.

Bok Choy (Pak Choi)
This variety is cultivated as a leaf vegetable, and has a flavor with notes of spinach and water chestnut with peppery undertones.

Bomdong
Leaves of these plants lay flat, and are typically used to make Kimchi and in salads.

Choy Sum (Caixin)
These leafy vegetable plants produce yellow flowers, and range from 4 to 16 inches tall. Leaves are consumed in soup, blanched, or stir-fried.

Field Mustard
These plants are harvested for their seeds, which are processed into an oil. They can also can serve as a great cover crop.

Komatsuna
(Japanese Mustard Spinach)
This cultivar is harvested and prepared in a number of ways. Leaves are large and green, and can be eaten at any stage of growth.

Napa Cabbage
This type of Chinese Cabbage produces green leaves with white veins. It is used in Kimchi, soups, and stir fries.

Rapini
(Broccoli Rabe, Raab)
Leaves, stems, and buds are all edible, and have a bitter taste. Native to Europe.

Tatsoi (Tat Choy)
Plants produce dark green leaves in a thick rosette. Creamy texture and distinctive flavor great for pesto, salads, and stir fries.

Turnip (White Turnip)
This cultivar produces a fleshy taproot, which weighs up to 2 pounds.

Caring for Brassica

Brassica plants are typically purchased as seed; they can either be direct-sown in the garden once the soil has warmed or started indoors 1-2 months before the last frost of the year and then transplanted out into the garden. They should not be grown in the same spot year after year due to buildup of pests and diseases. Individual plants should be spaced between 12 and 24 inches apart in rows 2-3 feet apart, though this varies depending on the cultivar grown. Check growing requirements on seed packets before planting. Plant Brassicas in a space in the landscape that receives full sun; ideally, they appreciate between 6 and 8 hours of sun each day for the best blooms. When these flowers are grown in less light, they will not flower as profusely. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 6.0 and 7.5 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants perform well in consistently moist soils. Water at the base of plants (avoid overhead watering); between 1 and 1.5 inches of water per week is ideal. To exclude pests that can cause damage to flower buds and foliage, consider using row covers.

Harvesting Brassicas
Species in the genus Brassica are grown for a number of different edible plant parts, including flowers, foliage, stalks, and storage roots. Although Brassica species have similarities in their preferred growing conditions, they differ in harvesting, storage, and use and therefore have all been separated out into the categories below:

Broccoli, Cauliflower, and Romanesco
These crops are grown for their edible flower inflorescences and are typically harvested between 50 and 90 days from transplanting out into the garden. Days to maturity varies depending on the type and cultivar of plant grown, so make sure to check growing instructions on seed packets for more specific information. Space plants between 18 and 24 inches apart in rows 2-3 feet apart for best airflow. Harvest these crops when the heads are firm and buds are still tight. In the case of romanesco or broccoli, harvest the main head when it is the size of a fist. The plants will continue to grow after the main head is harvested by producing side shoots with somewhat smaller heads. When growing cauliflower, cover the flowering head with surrounding leaves and tie them off at the top. This will block sunlight from reaching the flowering head, ensuring that it remains less bitter after harvesting. Cauliflower heads are typically between 6-8 inches in diameter when they are harvestable. These plants will not produce more heads after the main one is harvested.

Brussels Sprouts
Brussels sprouts form as buds along the main stem of the plant, just above each leaf axil. It is not recommended to direct-sow brussels sprouts outdoors; either purchase transplants that are 4-6 weeks old or sow seeds indoors 4-6 weeks before the last frost of the season. They are typically ready to be harvested between 80 and 100 days from transplanting. Space them 18-24 inches apart with 26-30 inches between rows. To encourage sprouts to mature more quickly, remove the top leaves three to four weeks before harvest. They will mature from the bottom up, and are harvested individually when they reach about 1 inch in diameter. Fresh-picked sprouts can last for up to 5 days in the refrigerator.

Cabbage
Cabbage plants are grown for their tight heads of delicate green foliage, which are used as wraps, added to soups, roasted, baked, or to make salads or stews. Cabbage is typically ready to be harvested between 70 and 75 days after planting, when heads feel solid and firm to the touch, similar to the feel of a softball. If heads are cracking or splitting, harvesting time has passed. The best time to harvest is in the morning before the heat of the day sets in. Using a sharp, clean knife, pruning shears, or a sickle, slice through the thick stem at the base of the cabbage head, keeping the cut as close to the head as possible. To encourage a second harvest, when cutting the head off make sure to leave behind some outer leaves and a long stem. This will allow for smaller, secondary cabbages to sprout. Cabbage should be kept dry, lightly wrapped in plastic, and placed in the refrigerator for up to two weeks.

Kale and Leafy Greens
Kale and other leafy green Brassicas are used as cut-and-come again plants. They are typically harvested between 50 and 55 days after seeding. The leaves will be ready for harvesting when they reach about 12 inches long. Using sharp, clean snips, pruners, or a knife, remove outer leaves, taking around 4 leaves from a plant at a time. After a few more weeks, harvest again. Harvested leaves can be stored in a paper-towel lined plastic bag for up to a week. Never wash kale leaves before storing them, as this can lead to excess moisture, causing them to spoil much more quickly. Instead, wash just before use.

Kohlrabi
Kohlrabi plants are harvestable between 40 and 60 days after sowing. The bulb should be between 2 and 4 inches in diameter when ready. Harvest with a clean, sharp knife or a sickle, making a cut on the stem just above the soil line. Trim off the leaves and store the bulb in the crisper drawer of the refrigerator. It will keep for several weeks. Leaves can be kept separately in a plastic bag wrapped in a damp paper towel. Kohlrabi can be peeled, diced, and frozen in a plastic bag. Kohlrabi is used raw or cooked, and has a mild, slightly sweet, peppery flavor, similar to a broccoli stem but with a milder flavor profile.

Turnip
Turnip plants typically take between 30-80 days on average before ready for harvesting, and are best when they are 2-3 inches in diameter. Shoulders visible above the soil can be measured before the root is pulled from the ground to make sure they are mature. To harvest, gently pull the plant up from the ground by grasping the foliage near the base. If soil does not give and the turnip is stuck, use a garden fork or shovel to loosen the soil around the root, being careful to not damage the turnip itself. Turnip greens can also be harvested as a cut-and-come-again leafy vegetable. Harvest outer leaves when they reach the desired size, leaving the center to continue growing. Never remove more than a third of the leaves at any one time, as the plant still needs to be able to photosynthesize to send nutrients to the root.

Seed-Producing Brassicas
Some species of Brassica are cultivated for their seeds, which are commonly made into seed oil. The species most commonly cultivated for their seeds are Brassica oleracea italica (Broccoli), Brassica campestris (Rapeseed), and Brassica juncea (Mustard). Seeds are harvested when seed heads have matured and dried out, which typically happens in summer to early fall. Pods will be brown but still flexible, and seeds inside should have turned from a green to a mature brown color. Lower pods will ripen before pods that are farther up on the flowering stem. Individual pods can be harvested one by one when they reach maturity, or the entire stem of pods can be collected by snipping it off near its base.

Disclaimer: Information contained on this website is strictly and categorically intended as a reference to be used in conjunction with experts in your area. Foraging and consumption of plant parts should never begin without the guidance and approval of a local plant specialist. The providers of this website accept no liability for the use or misuse of information contained in this website.

Propagation

Plants in the Brassica genus are most commonly propagated via harvesting and planting seeds, as they are generally treated as annuals in the garden. Keep in mind that when propagating using seed, resulting plants may not exhibit the same characteristics as the parent plant, especially if you are growing a hybrid cultivar. For instructions on how to propagate your Brassica plant, see the instructions below:

Propagating Brassica by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 75 degrees Fahrenheit. Seedlings can be planted out into the garden after the last threat of frost has passed.