|Posted by RickCorey (Everett WA 98204 - Zone 8a) on Nov 4, 2011 2:00 PM
Many agriculturally significant crops are members of the Brassica genus, which falls within the Brassicaceae family. That family has also been called the mustard family or "Cruciferae", so these cultivars are all cruciferous vegetables. Members of the genus Brassica are also sometimes called cole crops, cabbages, turnips or mustards. Brassicas are mostly annuals, some biennial.
The three closely-related ancestral species are:
- Brassica oleracea - (cabbage, broccoli, kale etc)
- Brassica rapa - (turnip, Chinese cabbage, some canola, etc) (includes B. campestris)
- Brassica nigra – (black mustard)
These three species hybridized and produced three species of "allotetraploid" Brassicas (tetraploids from two different parent species):
- Brassica juncea – (Indian mustard, brown and leaf mustards, Sarepta mustard)
- Brassica napus – (rapeseed, other canola & rutabaga)
- Brassica carinata – (Ethiopian mustard)
Common Names - - - - - - species and cultivar group
Cabbage - - - - - - Brassica oleracea, Capitata Group
Broccoli & Cauliflower - Brassica oleracea, Botrytis Group or Italica Group
Kale & Collard greens - - - Brassica oleracea, Acephala Group
Kai-lan - - - Brassica oleracea, Alboglabra Group (leaf vegetable / "Chinese broccoli")
Kohlrabi - - - - - - Brassica oleracea, Gongylodes Group (stem)
Brussels Sprouts - - - Brassica oleracea, Gemmifera Group
Turnip - - - - - - Brassica rapa var. rapa (root and leaves)
Chinese Cabbage - - - Brassica rapa, Pekinensis Group (once called celery cabbage)
Bok Choy - - - - - - Brassica rapa, Chinesis Group
Broccoli Raab / Rapini - - - Brassica rapa, Ruvo Group
Komatsuna - - - - - - Brassica rapa Perviridis Group ("Japanese Mustard Spinach")
Mustard species include Brassica rapa, B. nigra, B. juncea, B. elongate, B. narinosa, B. rupestris and B. tournefortii.
Brassicas are mostly cool-weather annual crops planted in early spring, late summer / early fall, or in winter hoop tunnels.
For example, Chinese cabbage's preference for decreasing day lengths and temperatures make it a good fall crop, but it can be grown in the spring if frost is avoided (frost makes young plants bolt to seed). Fall crops succession-planted after peas or beans benefit from the nitrogen left behind.
Spring crops can be direct-sowed after the last frost, or transplants with 4 true leaves can be hardened off and then set out after the last frost. Seeds tend to germinate best in warm soil, 68-85 F, but their 20-50 days to maturity may have to be over before summer heats up. Fall crops are more often direct-sowed.
Heat-tolerant and cold-tolerant cultivars exist within each group. Varieties that can't take heat are usually labeled "sow spring OR fall". Heat-resistant varieties may be labeled "sow spring THROUGH fall". Experimentation or local Master Gardeners will suggest varieties most suited to your local conditions.
Brassicas grown for their leaves may be harvested at any stage:
- tender, mild-flavored baby leaves for raw salads (for example, thinned seedlings)
- larger leaves pulled from each growing plant have more flavor (for salad or steaming)
- whole older plants for steaming, soup, stir-fry or pickling
A good strategy is to plant them thickly and eat the baby thinnings in salad for a few weeks. Later, thin the slower, smaller plants to give the others room, and eat these thinnings. Then let the most vigorous plants grow to maturity while you pluck a few of the largest outer leaves.
Saving seed lets you sow a large area thickly with little expense. However, Brassicas cross-pollinate very easily by insects within each species, and insects can travel hundreds of yards.
If you want to collect seed, but two cultivars within the same species bolt at the same time, uproot one of them or cover it completely with a floating row cover and weigh down the edges with soil. (You might uncover each cultivar on different days, so that each is pollinated but not cross-pollinated. Use different row covers for each cultivar so that you don’t transfer pollen.)
Brassicas tend to be heavy feeders, preferring well-drained, airy, fertile soil rich in organic matter and mineral nutrients. Work in manure the year before, and several inches of compost before planting, and / or side-dress or bury 1 cup of balanced fertilizer per 10 row feet.
Each Brassica variety prefers slightly different conditions. They may tolerate or even appreciate partial shade, especially if grown in hot summers.
Try to rotate where you grow Brassicas, ideally using the same soil only every third year, since they tend to share insect pests and soil diseases such as club root fungus. Floating row covers deter cabbage white butterfly caterpillars.
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|Posted by Marilyn (Kentucky - Zone 6a) on May 22, 2013 8:40 PM
"Common types of brassica used for food include cabbage, cauliflower, broccoli, Brussels sprouts, and some types of seeds. The genus is known for containing many important agricultural and horticultural crops. It also includes a number of weeds, both wild taxa and escapees from cultivation. It includes over 30 wild species and hybrids, and numerous additional cultivars and hybrids of cultivated origin. Most are annuals or biennials, but some are small shrubs. Due to their agricultural importance, Brassica plants have been the subject of much scientific interest. Six particularly important species (Brassica carinata, B. juncea, B. oleracea, B. napus, B. nigra and B. rapa) are derived by combining the chromosomes from three earlier species, as described by the Triangle of U theory.
A dislike for cabbage, broccoli et.al. can be due to the Brassica species containing a chemical similar to phenylthiocarbamide (PTC), a chemical which is either bitter or tasteless depending on one's genetic makeup.
Brassica species are sometimes used as food plants by the larvae of a number of Lepidoptera species."
Taken from wikipedia's page at: http://en.wikipedia.org/wiki/B...
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