Cabbage (brassica oleracea) can be a profitable and good regular crop to grow for cash flow on your farm. It is cheap, fairly easy to grow and has growing local and regional demand. The increased consumer demand for cabbage is a result of increased health awareness, its diversified uses and low price. If you are a livestock farmer (e.g rabbits, cows) cabbage can also make a good stockfeed.
What you’ll learn in this post
- Choosing your cabbage variety
- Soil and bed preparation
- Proper spacing & plant density
- Tips for cultivating your cabbages
- Disease and weed identification and prevention
- Harvesting and marketing your cabbages
So how do you select your seed variety?
Cabbage cultivars differ in terms of head size, density, head shape (conical/sugarloaf-headed, ball-headed/roundhead and large/drum-headed), colour (green, red or purple), leaf texture, disease resistance and date to maturity (early, mid-season or late-season). Other varieties are Chinese cabbage and Savoy. Savoy cultivators have crinkly leaves and are not very popular in Zimbabwe.
Careful selection of your cabbage variety is important to the success of your crop. You must read the seed packet to make sure you understand that particular seed cultivar’s specific properties. You can also test out different varieties to see which do best for you.
While yield is an important factor for all farmers, they are other important factors your must consider when choosing your cultivars.
These include disease resistance, your growing area, your growing season and your market/buyer’s preferences. While open pollinated seed varieties are cheaper than hybrids they tend to not do as well as hybrids in terms of yields, quality and disease resistance.
‘Star 3301‘ , ‘Star 3311‘ , ‘Golden Acre’, ‘Cabbage Attraction F1’ are good summer cultivars. Star 3301, for example, is great for its uniformity and high yield potential.
‘Conquistador’, ‘Megaton Hybrid’, ‘Star 3301’, ‘Star 3306′, ‘Green Coronet’, ‘Brunswick’, ‘Hercules’ are good cold/cool weather cultivars.
Other good cultivars: ‘Cape Spitzkool’, ‘Green Star’, ‘Grandslam’, ‘Matador’ and ‘Tenacity’
You should purchase your selected cabbage seed from reputable suppliers like Seed Co, National Tested Seeds and Charter Seeds.
Cabbage is a cool-season vegetable with smooth or crinkly leaves. While cabbages grow in the summer, they do better under cool and moist conditions. The optimum temperature for growth is between 18-20ᴼC. Cabbage are also fairly resistant to frost and can survive in very low temperatures without damage.
They are some heat-resistant cultivars that have been adapted to grow throughout the year. Summer cabbages are however more susceptible to pests and disease (such as black rot) and yields are also lower than in the cooler months.
Growth periods vary from 60-120 days from transplanting depending on the time of year, seed variety and other growing conditions.
It all begins with the soil.
We cannot emphasize this point enough. To produce a good yield of cabbage, you must understand your soil health and composition. It is, however, less complicated than it sounds.
Cabbages can be grown in a wide range of soil types. Though early cabbages grow best in well-drained sandy loam soil with good organic content, later types need heavier moisture retaining soil. The best soil pH for your cabbages is between 6.0-6.8.
To determine your soil pH, you need to get a soil test. We talked about soil testing in our tomato growing guide. A soil test will tell you if your soil is acidic or alkaline. It will also help you determine the amount of fertilizer and possibly lime or sulphur you need to grow a good crop.
If your soil test shows that your soil is acidic and needs lime, try to apply the recommended lime 2 to 3 months before planting your cabbages. This gives the lime enough time to raise the soil pH. If it shows that your soil is alkaline and needs sulphur, you can apply the sulphur at planting time because it works fast.
Good soil preparation involves loosening the soil to a depth of 1 foot or more and amending it with plenty of organic materials. If you don’t have enough time to make your own you can purchase some from a supplier by the truckload.
If you do this year after year it helps with water retention from rain and irrigation. Make sure that the organic material you use is thoroughly composted. If you use compost that is not well composted you run the risk of introducing weed seeds, pests and disease to your fields.
Cabbage belong to the cole crop family (Brassica oleracea), which includes broccoli, cauliflower, Brussels sprouts, collards, kale, rape and kohlrabi.
Interplanting: Fast growing french beans or lettuce can be interplanted with cabbage. Other plants you can interplant or companion plant with cabbages are beans, beets, celery, cucumber, onion and herbs such as thyme.
Seeds or Transplants: cabbage seed is typically sown directly in seedbeds or flat-cell trays and then transplanted into the fields. Plant seeds about a finger space apart. About 2kg per hectare may be required for direct seeding.
Seed trays: you can grow seeds in seed trays using potting mix or screened compost. Growing in trays can help you save on cost, and with producing seedlings that are more uniform. To plant in a tray, evenly sprinkle a good number of seeds across a whole tray of fresh planting mix. Space each seedling about a finger width. Then cover the seedlings with a thin layer of soil mix and then gently firm this down by hand. Finally, water the planting mix carefully and evenly. Leave seedlings to germinate in a sunny place.
Seedbed/ Nursery bed: your seedbed should be leveled and the beds raised a few centimeters to prevent water logging. Choose a location where cabbage family plants have not been grown in the past 3 years. It is important that the soil is firm and cleared before planting. Work the surrounding soil with your hoe.
Make your beds no more than 1 metre in width and any conventional length with walk paths.
Solarize your seedbeds to prevent against soil-borne diseases. To solarize you need to cover your seedbed/nursery bed with polythene/plastic sheets.The sun will heat the soil through the plastic and help kill off nematodes. You can also spray your soil with a certified herbicide if you have limited time.
Make sure that the seedbed is well watered using a watering can with a rose on the sprout. Cover your seedbed with straw mulch to help retain soil moisture. If the soil in the seedbed feels dry, it’s time to water. Label the seedbed and observe it twice a day to make sure that optimum conditions are maintained throughout the germination process.
Plant extra seeds to ensure that you have sufficient seedlings to cover the land area you want to plant.
Cabbage seedlings will sprout in about 7 to 12 days. Once they emerge you can remove mulch to expose the seedling to adequate sunlight which helps support good growth. Water your seedling frequently but lightly to prevent the topsoil from drying out and to keep the seedlings moist. Thin out the seedling to about 7.5cm tall keeping the strongest seedlings.
Seedlings are ready for transplanting about 4 weeks after sowing. You can harden the seedlings off before transplanting by reducing watering 2 days before planting and fertiliser applications at least 7 days before transplanting. This helps the seedlings to recover quickly from transplanting shock.
Give a good watering the day before transplanting in order to restore a good water regime and facilitate easy transplanting.
Transplant only the young, vigorous seedlings into the moist soil when they have 5-6 true leaves. It is best to transplant the seedling in the cooler part of the morning or evening. Make planting holes wide enough to accommodate spread-out roots; set the lowest leaves at ground level, firm soil around each seedling and water thoroughly immediately afterwards. This establishes your seedlings into the field.
Plant Density: Your plant density can be determined by the market you are targeting and your available resources. If you are supplying the loose-head or open market like Mbare Musika you should grow about 26,000 to 30,000 plants/ ha. This market focuses on head size and weight.
If you are targeting retail supermarkets like Pick and Pay and Spar then a plant density of about 35,000 to 40,000 plants/ ha. is common. This market values quality, uniformity, firmness and colour. Their cabbages are typically displayed on a shelf.
Proper Spacing: The optimal plant spacing per acre in the main field is determined by the plant variety. As a general guideline, you should make rows 60cm apart. Plant compact varieties, those with smaller heads, 30cm apart. Plant larger head varieties 45cm- 60cm apart in rows. Your seed packet can provide more specific guidance on plant spacing. You can use a long string as a guide for planting.
Mulching: mulch around seedling to help retain moisture between waterings. Mulching also keeps your farm neat and cuts down on weeds. Spread coarse mulch such as straw (it’s usually weed-free and cheaper than black plastic mulch ) around and between cabbage plants in a layer 8 to 10 inches deep. It will compress over the course of the growing season. If the mulch becomes thin, you should add more.
Record keeping: It is important to track what you have seed varieties you planted in what field, date of seeding, spacing and fertiliser and water usage for good farm management. Mark all these in your farm notebook, this can be a simple school exercise book. Get one now during back to school!
Cabbage is a heavy feeder and requires supplemental fertilisation in the form of manure or compost, nitrogen (N), phosphorus (P) and potassium (K) to boost growth. Fertiliser programmes should be based on the soil analysis of each field. Without a soil test you are taking a chance when you fertilise your plants. If you don’t use enough fertiliser your plants will not thrive. If you use too much you risk wasting money and polluting your water through run-off.
Check your plants for nutrient deficient symptoms. Nitrogen deficiency is evident with leaf colour which is usually yellowish or pale green. The plant grows slower and has thin and hard stems.Cabbage require about 200 to 250 kg nitrogen per hectare.
Phosphorous deficiency: the plants grow slowly. The stems are thin and short, leaves develop a purple color.
Potassium deficiency: you see it in the margin of the leaves which are grey or tan areas.
It is better to apply fertiliser to each plant once it has been established, again in 3 weeks, and again when the first heads start to form.A week after transplanting, apply a smaller application (called a side dressing) of LAN (Limestone Ammonium Nitrate) or well-rotted manure near the base but not touching plants, and water well.
You can purchase fertiliser from a reputable agro-dealer in your area.
3 carefully measured and well-timed applications will help produce a good yield.
While hand pulling is preferable, weeds can also be controlled chemically using herbicides. There are a number of herbicides that are registered for use on cabbages.
Watering is the lifeblood of brassicas, and supplemental irrigation is necessary. They are cool-season, moisture loving plants that are susceptible to drought stress. Provide your plants adequate and regular supply of water to avoid split heads.
They are several ways to irrigate your cabbages. If you have a small plot you can water using a watering can. For larger more commercial farms, you should consider installing a drip irrigation system.
Drip irrigation systems are the most efficient in terms of water use, but they do require more planning. Drip irrigation applies water directly to the root zone, where it’s needed, with minimal waste or runoff. Irrigation layout plans of mains and secondary lines need to be made early. Test out the system to ensure that it is operating efficiently.
Due to cabbages’ large leaf area, they require at least 25cm of water per week to sustain good growth. You need to water your plants evenly to produce good heads. Avoid excessively and unevenly watering as it can cause a sudden growth spurt that will make the developing cabbage head split. If you see you cabbage start to crack, twist the plant a half turn and pull up to slightly dislodge the roots and thus slow the plants growth.
Don’t water foliage (leaves) during cool weather or periods of humidity, because constantly wet leaves are prone to disease. Cut back on water use as cabbage matures. You can use your finger to check your soil moisture.
Cabbages and brassicas (the cabbage family) are susceptible to a number of diseases, so a good pest management system is critical.
Here are some of the common pests that affect cabbages:
Diamond back moth larvae: these suck the sap from the cabbage plant and cause it to turn whitish while also stunting growth.
Cutworms: as seedlings cabbages are most at risk of cutworms. You can protect them with cutworm collars to enable them to mature and produce their crop.
Bollworms: can also be a problem in summer. Thoroughly spray all parts of the plant with an insecticide such as pyrethrum to which you added a wetting agent (such as a dishwashing liquid). So water does not run off leaves.
Mealy aphids: can affect cabbages. They form grey fluffy patches on the underside of leaves and end up stunting and spoiling the cabbage plants. You can pick these off as they appear.
Clubroot: this is the worst disease for brassicas. It is a soilborne fungus that invades the root system. The plants live but fail to thrive because it prevents water and nutrient absorption. In areas where clubroot is common, transplants should be treated with fungicide. You can also take preventative action against clubroot by liming your soil to raise its pH and rotating your crops to avoid disease build-up.
Caterpillars: large white and small caterpillars. In mild attacks, you can pick off caterpillars by hand. Can be removed by insecticide, or prolonged heavy spraying with water. Ordinary salt in water is an effective control too and will kill slugs too.
Cabbage root fly: this is one of the worst diseases for cabbages. A white larvae feeds on cabbage roots below the surface, stunting growth and causing plants to wilt and die. The signs of infection are the yellowing of the outer leaves. To prevent cabbage root fly, you can grow your cabbages under an insect-proof mesh.
Nematodes: several types of nematodes can affect your cabbages. These cause the plants to be stunted and to show signs of moisture stress.
You can use chemical or non-chemical control methods to protect your crops.
Integrated Pest Management (IPM): pest and disease can be avoided through Integrated Pest Management (IPM) procedures. IPM help lower production costs and are also safer for consumers and the environment.
The following will help limit the pests and disease in your cabbage fields:
- Choose tolerant and disease resistant cultivars
- Solarize your seedbed before planting to remove nematodes and weeds
- Practice a 3 or 4-year crop rotation to reduce disease build-up
- Use drip irrigation to prevent leaf diseases
- Use floating row covers loosely to protect against caterpillars, aphids, and insects
- Plant cabbage after nitrogen fixing plants
- Clean up and remove all crop residues at the end of the season
- Place yellow and blue sticky traps around your crop
- Good weed management including mulching and hoeing to remove weeds
- Monitor your fields for pests weekly and remove diseased plants immediately
Sprays & pesticide controls: If the problem is harder or insects are too numerous or small you may need to spray. You should contact your extension office, a horticulture expert or a supplier to help you correctly identify the pest or disease and to recommend the correct insecticidal or pest management sprays. Always read and follow the label before spraying. Handle chemical sprays and even organic sprays (e.g. pyrethrum, insecticidal soap and retonone) with extreme care. Make sure you make a note of what you used and when.
With good crop management, seed variety and season it is possible to yield about 10-15 tons per hectare, and even more in certain cases.
When harvesting fresh vegetables such as cabbages, it is important to practice good field hygiene to ensure crops are free of contaminants. Make sure that your buckets are clean and your cutting knives are clean and sharp to avoid spreading disease.
Proper care and handling are important to avoid bruising and damaging of your cabbages. You don’t want to ruin your crops, after all, that hard work. Damaging your cabbage heads will result in their reduced saleability.
You and your farm workers/contractors should individually harvest your cabbages when the weather is cool such as during the morning or early evening because the high temperature can cause damage and wilting. Immediately place your cabbages in a cool temporary storage out of the direct sun.
Harvesting equipment should be stored away after harvesting.
Packhouse equipment (tables) and clothing (boots, gloves, aprons and overalls) needs to be cleaned and sanitized prior to harvesting and packing cabbages. This helps prevent contaminants.
Prices: the current average price per head of cabbage is about 50 cents/ or a $1 for 2 heads . You should ask around or use market tools to track market prices.
Viability: The viability of your cabbage production operation is based on your input costs ( seeds, fertilizer, irrigation water, labor and machinery time). You need to track and calculate all these to get an idea of your cost of production.
Bottom Line: Profitably from growing cabbages comes from good growing practices, managing expenses and also year round production to improve consistency and prices.