Growing Cabbage

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Savoy cabbage with crinkled leaves tolerates frost

Savoy cabbage has pretty crinkled leaves and is among the most frost-tolerant cabbage varieties, making it a great choice for fall gardens.

Cabbage is a cool-season vegetable suited to both spring and fall. It belongs to the cole crop family (Brassica oleracea), which includes broccoli, Brussels sprouts, cauliflower, collards, kale, and kohlrabi. The trick to growing cabbage is steady, uninterrupted growth. That means rich soil, plenty of water, and good fertilization.

Soil, Planting, and Care

Set out new spring plants early enough so that they can mature before the heat of summer, about 4 weeks before the last frost. Plant 2 or 3 varieties with different maturities for a longer harvest. You can also plant through black plastic to help warm the soil in spring. New plants just out of a greenhouse need to be protected from freezing weather. Plant fall cabbage 6 to 8 weeks before the first frost. Growing plants that have been exposed to cool weather become “hardened” and are tolerant of frost. Cabbage that matures in cool weather is deliciously sweet. Like most vegetables, cabbage needs at least 6 hours of full sun each day; more is better. It also needs fertile, well-drained, moist soil with plenty of rich organic matter. The soil pH should be between 6.5 and 6.8 for optimum growth and to discourage clubroot disease.

cabbage transplant in fertile soil

Cabbage needs fertile soil and adequate moisture from the time you set out the plants. Stunted plants won’t recover if stressed.

To be sure about your soil pH, get the soil tested. You can buy a kit or have a soil test done through your regional Cooperative Extension office. Apply fertilizer and lime if needed, using the results of the soil test as a guide.

In the absence of a soil test, add nitrogen-rich amendments such as blood meal, cottonseed meal, or composted manure to the soil or work a timed-release vegetable food such as 14-14-14 into the soil before planting. Or you may instead choose to feed regularly with Bonnie Vegetable & Herb Food. The plants love the liquid feeding.

Cabbage is easy to transplant. Set plants so that 1-2″ of the main stem is buried. Space according to directions on the Bonnie label. Generally, this is 12 to 24 inches apart in a row, depending upon the variety and the size of head it makes. For maximum size, be generous with the spacing. The Bonnie Mega-Cabbage, for example, needs all the room you can give it!

Cabbage demands even moisture to produce good heads. Mulch with compost, finely ground leaves, or finely ground bark to keep the soil cool and moist and to keep down weeds. Water regularly, applying 1 to 1.5 inches of water per week if it doesn’t rain. You can measure the amount of water with a rain gauge left in the garden.

Fertilize plants again with a liquid fertilizer such as fish emulsion or 20-20-20 after they begin to develop new leaves and when they start forming heads.

Troubleshooting

A cabbage leaf with holes is a sign that cabbage loopers or worms may be eating the plant.

Holes in a cabbage’s leaves are a sure sign that cabbageworms or cabbage loopers may be attacking the plant. Look for these green pests on the underside of leaves and pick them off.

The best way to avoid problems is to keep your cabbage healthy and keep your garden clean. The main insect pests include cabbage loopers, slugs, imported cabbageworms, cabbage root maggots, aphids, and flea beetles. Disease problems include black leg, black rot, clubroot, and yellows. To prevent diseases from building up in the soil, avoid planting cabbage or other cole crops in the same spot each year. Rotate with a non-cole crop for 2 years before returning to the same spot.

Harvest and Storage

A hand squeezes a cabbage head to determine if it’s ready to harvest.

Squeeze the cabbage head to test whether it’s ready to harvest or not. If the head feels solid and firm, it’s ready to be cut from the base of the plant. If it feels loose, leave it in the garden to harden up a little longer.

Cabbage is ready to harvest when the head forms, right? No, sometimes they look ready, but they aren’t. You can test the head’s solidity by squeezing it. A head that looks solid and ready may still be flimsy and loose leafed on the inside. When it feels firm, cut the head from the base of the plant. Some varieties hold well in the garden for weeks, while others need to be cut soon after the heads are firm. Our descriptions of Bonnie cabbage varieties indicate which ones hold best. If a head cracks, cut it right away. If you want to experiment, you can leave the harvested plant in the garden. If the weather is still cooperative, they develop loose little heads below the cut that are fun to serve as mini cabbages. Heads keep for several weeks in the fridge.

FAQs

Why do butterflies fly around my cabbage plants?

Those butterflies (white or brown) are probably the moths of cabbage worms. They lay eggs on the plants. The eggs hatch into the worms that cause considerable damage unless controlled. Most control strategies are aimed at the developing larvae rather than the mature moths themselves.

Why are there holes in my cabbage leaves?

Your plant is probably being chewed by cabbage loopers or cabbageworms. Treat the cabbages with a product containing Bacillus thuringiensis (Bt) such as Dipel¨, a biological-type insecticide. This must be eaten by the worm and is activated in the worm’s alkaline gut. The worm then dies slowly from terminal constipation. This takes two to three days, which means the worms are not killed immediately.

What causes large, lumpy swellings of my cabbage roots?

Swellings and distorted roots on stunted, wilted plants are symptoms of clubroot, a disease caused by a fungus that remains in the soil for years once it becomes established. It is spread by moving infested soil and by infected transplants. Other cole crops (like broccoli and cauliflower) are susceptible. Destroy infected plants (including the roots) and for at least four years avoid planting any member of the cabbage family there, including radishes, turnips, and ornamental relatives of cabbage. To discourage the disease, add lime to raise the soil pH to 6.8.

What can I do to prevent my cabbage heads from splitting?

Splitting is caused by the pressure of excess water taken up after the heads are solid, or water being taken up quickly after dry weather. Cutting the roots (spading on two sides of the plant) or breaking the roots (lifting and twisting the head to one side) may reduce splitting or bursting, but it also damages the plant and requires that you harvest soon.

What causes cabbage to develop seed stalks rather than solid heads?

All cabbage will either head up or go to seed at some point in time. Cabbage plants “bolt” (form premature seed stalks) when exposed to low temperatures (35 to 45 degrees F) for extended periods if plants are set out too early or if an unseasonable blast of cold assaults the garden. After the plants have stems as large as a pencil, they are vulnerable to this “cold conditioning,” which initiates the flowering.

198 thoughts on “Growing Cabbage

  1. I have planted lots of cabbage plants this year to make sour kraut. Someone told me that I will have larger heads if I cut off the outer leaves. Is this correct? I have not had this confirmed, so I’m afraid to cut the leaves.

    • Hello Sharon,
      I am not sure if that is true or not. I do remove some of the larger leaves during the season…to make cabbage rolls :) – danielle, Bonnie Plants

    • I’m not much of a gardener by from a Agro science perspective cutting off the larger outer leaves reduces the photosynthetic ability of the plant which will slow its growth. The plant will grow faster if there is a larger surface area of leaves which are able to access more sunlight. Maybe this will help?
      A little experiment could never go astray with removing some of the outer leaves of half your cabbages and leaving others on the other half of your cabbages.

      I am researching a brassica market farm at the moment and I’m almost certain the farmer does not remove outer leaves and still gets excellent, larger cabbages. Cabbages respond more to the nitrogen content in the soil more than any other factor. You could try companion planting with a nitrogen fixer such as clover to increase your cabbage head sizes.

      Cheers, Sara

  2. I planted chinese cabbage about 2 wks ago, they are really growing, but today when I looked at them I noticed that they are forming a head that resembles broccoli. They couldn’t possibly be bolting already, could they? I live in coastal Oregon, we have an extremely mild climate, no extreme weather. Is that what they should look like? Just the larger ones that I planted first are doing that.

    • Hello Kathy,
      When a Chinese cabbage bolts, the small unopened flower buds do resemble broccoli heads – which are the unopened flower buds. A couple of reasons that Chinese cabbage will bolt or form a flower head – exposure to low temperatures (35 to 45 degrees F) for extended periods. After the plants have stems as large as a pencil, they are vulnerable to this “cold conditioning,” which initiates the flowering. Bolting also occurs when warm temperatures rocket in early spring. If you are unsure about your Chinese cabbage, you can upload a picture to the Bonnie Plants Ask an Expert site. – danielle, Bonnie Plants

  3. Danielle
    I have planted cabbage in 2011 and 2012 for this yr.
    they formed beautiful leaves, but the cabbage didnt form the normal tight heads. I also did the red cabbage,(2012) only one formed the tight head. What am I doing wrong? By the way we do container gardening. Everything else we grow, grows beautifully. They are all planted in the same lg. 4×8- 8″deep
    bx. beautiful leaves, but not tight heads. dee

    • Hello Dee,
      I am not sure where you are gardening, but spring and early summer heat can attribute to loose heads. Cabbages grow best when temerpatures are in the 60′s. When they head up under higher temperatures, they often produce loose heads followed by flowers. I grow cabbages in the late winter, but they grow best for me in the Fall. Loose heads have also been attributed to excessive fertilization and insufficient water. Hope this helps. – danielle, Bonnie Plants

  4. Hi Danielle,
    We started cabbage last year and we ended up getting some pretty good cabbage heads. The plants survived the winter but it doesn’t seem like they are going to form another head. They are growing straight up and it looks like they are going to flower. Will they not form heads? Is there anything I can do? Thanks.

    • Hi Kielly,
      If the cabbages are starting to flower, the life cycle is pretty much over with. Enjoy the pretty flowers, I have been enjoying them for weeks now. Pollinators love them. It will be time to plant cabbage again soon :)

      • mine also lasted the winter after cutting off nice firm heads last fall. They have flowered and now seem to be forming multiple little heads. Why do I need to put out new plants or seeds each year? Why is it not ok to just let them cycle through and grow again the next year?
        Please explain.

        • Hello,
          You can let the plants cycle through. You still have some vigor in your plant – thus the smaller heads forming. While it may be possible to get a couple of harvests, a cabbage will not produce much more than that. – danielle, Bonnie Plants

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