Cabbage grows best in cool weather, but certain cultivars are also adapted for the warmer months. In the cooler areas of the country, where frost usually occurs early or late in the season, Glory of Enkhuizen, Kiaps Spits, Green Coronet and Gloria can be planted from January to March, and Green Star and Bonanza, from August to January. In the warmer areas of the country, where little to no frost occurs, Glory of Enkhuizen, Kiaps Spits, Green Coronet and Gloria can be planted from March to May, and Green Star and Bonanza, from January to December.
Cabbage grows best when plantlets are grown and then planted out. You can grow your own plants or buy them from a nursery. Remember that cabbage plantlets cannot be planted out before the age of five to six weeks.
If you want to plant out at the beginning of February, for instance, you must already sow the seed in the middle of December. Cabbage will grow well on most well drained soil types.
That means that water must not lay on the ground surface too long after the plants have been watered. Where this is the case, compost must be dug into the soil. Shallow soils on a hard rocky, clayey or lime layer, must be avoided. Cabbage takes up many plant nutrients from the soil. We put plant nutrients into the soil by digging compost and fertiliser into it. A great deal of organic plant food such as compost and manure is necessary for the plant.
When the bed is dug over, 4 kg of compost or manure per square meter (m2) of ground can be dug into the soil. By the way, 1 m2 equals the size of a square meter, the sides of which consist of spades. Compost and manure do not, however, provide the cabbage plant with enough plant nutrients. It also requires nitrogen (N), phosphorus (P) and potassium (K). It is most important first to analyses the soil to determine its nutrient content. Remember: an excessive amount of nutrients will burn the plants and a too small amount will result in poor growth. If a soil analysis has not yet been done, the following quantities of fertiliser may be applied: At planting: 75 g of 2:3:2 (30) per m2.
These plant nutrients are a mixture of nitrogen, phosphorus and potassium. This means that three plant nutrients are given to the plant simultaneously. These nutrients must be dug into the soil well, before planting. Four weeks after planting:
25 g of ammonium sulphate per m2, or
20 g of limestone ammonium nitrate (LAN) per m2.
As soon as the plants begin to form heads, the following can be applied: 25 g of ammonium sulphate per m2, or 20 g of limestone ammonium nitrate (LAN) per m2.
Take care not to let the plant nutrients touch the plants as this can burn the stems. Water the plants as soon as possible after having fertilized them, so that the nutrients can dissolve and be washed into the soil. Before the plantlets are planted, the soil must be dug over, clods, stones and weeds must be removed, and the soil must be leveled. The cabbage plantlets are planted in rows. In-row spacing must be approximately 40 cm and between-row spacing must be 60 cm. The soil in which the plants were grown must be moist when the plants are taken out to be replanted. They must be lifted carefully out of the ground so that the roots are not damaged. Choose short, sturdy, healthy plants to plant out. After they have been taken out, they must be covered with a moist cloth or hessian until they are planted.
They must preferably be planted on cool, cloudy days or late in the afternoon. The plantlets must be planted in moist soil which is then firmly pressed down around the plant. After the plantlets have been planted, they must be watered as soon as possible. A mulch of grass clippings, dry leaves or straw between the plants prevents evaporation of soil moisture and also suppresses weed growth. If the soil is allowed to become too dry, and it is then watered, it may happen that the cabbage heads burst open. In cool weather, cabbage can be watered once a week; in very hot weather, two to three times a week. Cabbage can be harvested as soon as well-developed hard heads have formed. There are at least four kinds of insects that damage cabbages during the growing season. They are:
* the American bollworm,
* the diamondback moth, and
* The barged bug.
The American bollworm and the diamondback moth eat holes in the cabbage leaves. Aphids suck out the sap of the plant and the leaves turn yellow and become misshapen. The barged bug also eats the leaves and causes great damage.
Prior to planting, the soil needs to be prepared, usually by some form of tillage or chemical “burn-down” to kill the weeds in the seedbed that would crowd out the crop or compete with it for water and nutrients. Tillage methods can be divided into three major categories, depending on the amount of crop residue they leave on the surface. Residue slows the flow of run off that can displace and carry away soil particles. * Conventional tillage – Until the last decade or so the standard tillage practice for corn was use of the moldboard plow for primary tillage followed by several secondary tillage’s and mechanical cultivation after the crop was up. * Reduced tillage is usually done with a chisel plow and leaves 15% to 30% residue coverage on the soil. * Conservation tillage leaves at least 30% residue coverage on the soil. Conservation tillage methods include no-till, where no tillage is done at all and seeds are placed directly into the previous season’s crop residue; strip-till, in which only the narrow strip of land needed for the crop row is tilled; ridge till; and mulch till.
Soils — Cabbage grows well on a wide variety of soils, but a well-drained sandy loam with high organic matter content is preferred. Avoid soils that dry rapidly. Herbicides are used in all these methods to kill weeds. A common myth is that more herbicide is used with conservation tillage methods, but in fact farmers rely on herbicides for weed control under all tillage systems, and the amount used is more or less independent of tillage method. Impacts of soil erosion Soil erosion has both on-farm impacts (reduction in yield and farm income) and off-farm impacts (contaminated water due to the sediment and associated contamination from nutrients and pesticides carried on the soil particle). On-farm impacts due to the loss of soil and nutrients include:
* lower fertility levels
* development of rills and gullies in the field
* poorer crop yields
* less water infiltration into the soil
When fertile topsoil is lost, nutrients and organic matter needed by crops often are removed along with it. Erosion tends to remove the less dense soil
constituents such as organic matter, clays, and silts, which are often the most fertile part of the soil.
All brassica crops grow best in partial shade, in firm, fertile, free-draining soil. * Start digging over your soil in autumn, removing any stones you find and working in plenty of well-rotted manure or compost. * Tread on the soil to remove any air pockets and make the surface very firm. * Brassicas will fail if the soil is too acidic so add lime to the soil if necessary, aiming for a pH of 6.5-7.5.
Due to their large leaf area, cabbage requires at least a 25 cm (1 inch) of water per week to sustain good growth. Excessive watering late in the season can cause head-splitting. Uneven soil moisture can cause fluctuations in the uptake of nutrients and lead to tip burn or head-splitting. Soil should be kept at 60 to 70 percent field capacity to ensure good yields and head quality. The fact that cabbage is a cool season crop indicates that it responds favorably to lower temperatures with adequate amounts of rainfall. Cabbage also requires well-drained soil. Soil that is not well-drained should either have drainage tiles installed or have some organic matter added to it to improve soil aeration.
Direct-seeded cabbage is usually planted in early to mid-May. Direct-seeded cabbages are planted 5 to 8 cm (2 to 3 inches) apart (1.1 kg/ha or 1 lbs. /ac) and thinned later. The following are seeding rates for transplanted cabbage:
* in-row spacing – 25 to 46 cm apart (10 to 18 inches) apart
* between-row spacing – 0.76 m (2.5 feet) apart
* in-row spacing – 30 to 46 cm (12 to 18 inches) apart
* between-row spacing – 0.7 to 0.9 m (2 ½ to 3 feet) apart Late-season:
* in-row spacing – 46 to 61 cm (18 to 24 inches) apart
* between-row spacing – 0.7 to 0.9 m (2 ½ to 3 feet) apart Row spacing will be dependent on your tillage, planting and harvesting equipment. Many cabbage growers in Saskatchewan use transplants to reduce seed costs, accelerate crop development, increase yields, overcome problems with cruciferous flea beetles destroying emerging seedlings, eliminate costs associated with thinning the direct-seeded crop and avoid soil crusting problems in clay soils.
In warm, dry springs flea beetle populations are high enough that flea beetles are already present on the crop as it emerges. Damage at emergence injures the growing tip, causing bolting, misshapen heads or death. Growers who transplant have the option of planting and then following behind with an insecticide treatment to kill the flea beetles before any damage can occur. The same can and is done for direct-seeded cabbage, but the grower must be more vigilant and closely watch for seedling emergence. They can then make a pass with an insecticide. A seed row treatment, such as Di-Syston 15 G, can be applied during planting to control cruciferous flea beetles.
Seed costs for cabbage have increased over the last 10 years, primarily because of the shift to hybrid types. Due to the seed’s higher value, it is best to treat it with a fungicide, such as Thiram 75WP, to prevent seedling blight, damping off and seed decay. Hot water treatment of the seed is effective against alter aria, black rot and blackleg. This treatment can be specially done by your seed company, but must be done prior to seed coating.
Nearly all brassicas should be planted in a seedbed or in modules under glass and then transferred. Seeds should be sown thinly, as this reduces the amount of future thinning necessary and potential risk from pests. * Sow seeds 1.25cm (1/2in) deep and rows should be spaced 15cm (6in) apart. * Once the seeds have germinated, thin the seedlings to 7.5cm (3in) between each plant. * Cabbage and broccoli seedlings are ready for transplanting when they’re between 6 and 8cm high (2.5-3in). Brussels sprouts and kale should be 15cm (6in).Water the day before moving, and keep well watered until established. * Space the plants according to the instructions on the seed packet. It can vary from 30cm for small cabbages to 75cm for Brussels sprouts.
* Brassicas are affected by a wide range of pests and diseases, especially the fungal disease, club root. The roots become stubby and swollen and can develop wet rot, while leaves become yellow and wilt, causing severe stunting of growth. Remove any infected plants from the ground and destroy. * Make sure the soil is adequately limed and well drained, and do not plant cabbages in the same place the following year. * Rotate your crops annually to avoid disease. Don’t grow brassicas on the same plot more often than one year in three, as moving the crop helps avoid the buildup of soil pests and diseases. * Brassicas are a particular favorite of birds so use a deterrent to stop them picking off seedlings. CDs on string can be effective. They’re also susceptible to attack by the caterpillars of the cabbage white butterfly. Try covering crops with a crop protection mesh. It keeps the butterflies out, so they can’t lay their eggs on the plants.
* Club root – (Plasmodiophora brassicae) is a soil borne disease that is more active in soils that are slightly acidic. Saskatchewan’s alkaline soils are a deterrent to this pest. Wart-like growths or knots form on the base of the plant, restricting water and nutrient uptake. Control measures include using clean transplants, maintaining soil pH above 7.3, disinfecting all tillage equipment, increasing years between cruciferous crops and keeping cruciferous weeds under control. The field can be fumigated; however this is costly. * Blackleg – (Phoma lingam) this fungal disease is active at low temperatures. Symptoms include seedling death, or bluish growth on the stems of older plants near the base.
Upon germination, infected seedlings are covered by lesions that can be spread to adjacent plants by rainfall or irrigation. Blackleg can be controlled with the hot water treatment (see Black rot). Eradicate cruciferous weeds and have at least a three-year crop rotation with other cruciferous crops. * Downy Mildew – (Peronospora parasitica) is a fungus that over-winters in perennial plants and infected plant debris. Symptoms include a tan paper-like appearance that continues to develop into larger, sunken areas on the head. Control measures include a three-year crop rotation with non-cruciferous crops and preventative applications of Bravo 500, Clean Crop Copper 53W or Zinc b 80W.
* Cruciferous flea beetle – (Phyllotreta cruciferae) is the most serious insect pest facing Saskatchewan cabbage producers. These small black beetles attack cabbages throughout the growing season. They are especially dangerous in the spring when seedlings are emerging. The large acreage of canola in Saskatchewan ensures that there will always be a sizeable population of flea beetles in the province. Flea beetles feeding on emerging cabbage crops cause seedling death, uneven growth and maturity. Flea beetles have one generation per year, but the adults appear twice, once early in the spring and again later in the fall. * Control measures include crop rotations of more than three years with non-cruciferous crops, eliminating cruciferous weeds and not planting near fields that have cruciferous crops. Flea beetles can be controlled chemically by using foliar applied Ambush, Di-Syston, Endosulfan, Matador, Pounce, Ripcord, Sevin, Thiodan or Thionex.
* Cabbage Maggot- (Delia radicum) is an underground pest that feeds on the roots of the host plants. The survival rate of the eggs is highest when the weather is cool and moist, much like spring conditions. Cabbage maggots can severely stunt growth or kill seedlings, and can lower quality and reduce yields of more mature plants. The maggot is the larval stage of the cabbage maggot fly, which looks much like a common housefly. The lifecycle has two generations per season. Control measures include a crop rotation of three or more years away from cruciferous crops and eradication of cruciferous weeds. The main chemical control for cabbage maggots is an insecticide drench placed near the seed at planting. Control products include foliar applied Lorsban, Pyrinex, or Sniper.
* Imported Cabbage Worm and Cabbage Looper – (Pieris rapae) and (Tricoplusia Ni) are also referred to as the cabbage butterfly. Imported cabbage worm larvae, which are light green in the larval stage, are incredibly destructive. They chew large holes in the leaves and head of cabbages. Their waste products also contaminate the head. Control measures include a crop rotation of three or more years away from cruciferous crops and eradication of cruciferous weeds. The main chemical control is repeated foliar applications of the one of the following products: Ambush, Cymbush, Decis, Diazinon, Dibrom, Dylox, Endosulfan, Guthion, Lannate, Malathion, Matador, Methoxychlor, Monitor, Orthene, Pounce, Ripcord, Sevin, Sniper, Thiodan, or Thionex. Dipel, (Bacillus thuringiensis ssp. Kurstaki) is a biological insecticide that also controls cabbage worms.
* Diamondback Moth – (Plutella xylostella) does not over-winter in Canada but rather the adult moths fly or blow up each year from the United States. Larvae chew irregular patterns into the lower leaves. The larvae may also tunnel into the head of the cabbage, hurting its market potential. Control measures include monitoring the crop for arrival of adults and eradicating any cruciferous plants, including weeds and the refuse left over from early harvests of cruciferous crops. Chemical controls include the following products: Ambush, Cymbush, Decis, Diazinon, Dibrom, Dipel, Dylox, Endosulfan, Guthion, Lannate, Matador, Monitor, Orthene, Pounce, Ripcord, Sevin, Sniper, Thiodan, or Thionex Weeds
Competition from weeds early in the season will slow both emergence and early growth. Weeds can be controlled with shallow tillage to destroy any weed seedlings. Weeds can be controlled chemically with Devrinol, Venture, Poast and Treflan. Check label recommendations for application rates, timing and weeds controlled.
* Head splitting – is caused by excessively rapid growth. This problem can be managed by ensuring there is adequate organic matter to hold soil moisture, providing consistent even watering, avoiding over-fertilizing with nitrogen, and spacing close and evenly to discourage excess and rapid root growth. Heads that are cracked should be culled, as they become an entry point for secondary infections such as soft rot. * Tipburn – is caused by inadequate amounts of calcium in the youngest region of the plant. Usually, this is due to rapid growth. Tipburn occurs when the translocation of calcium to the growing tip is slowed. There are no initial outer symptoms on the cabbage head, but the inner leaves turn brown. Tipburn can only be controlled by discouraging rapid growth (see head splitting). Adding calcium to the soil does not fix this problem. Tipburn is very cultivar specific.
Weed control is the botanical component of pest control, using physical and chemical methods to stop weeds from reaching a mature stage of growth when they could be harmful to domesticated plants and livestock. In order to reduce weed growth, many “weed control” strategies have been developed in order to contain the growth and spread of weeds. The most basic is ploughing which cuts the roots of annual weeds. Today, chemical weed killers known as herbicides are widely used.
Weeds can compete with productive crops or pasture, or convert productive land into unusable scrub. Weeds are also often poisonous, distasteful, produce burrs, thorns or other damaging body parts or otherwise interfere with the use and management of desirable plants by contaminating harvests or excluding livestock. Weeds tend to thrive at the expense of the more refined edible or ornamental crops. They provide competition for space, nutrients, water and light, although how seriously they will affect a crop depends on a number of factors. Some crops have greater resistance than others- smaller, slower growing seedlings are more likely to be overwhelmed than those that are larger and more vigorous.
Onions are one of the crops most susceptible to competition, for they are slow to germinate and produce slender, upright stems. Quick growing, broad leafed weeds therefore have a distinct advantage, and if not removed, the crop is likely to be lost. Broad beans however produce large seedlings, and will suffer far less profound effects of weed competition other than during periods of water shortage at the crucial time when the pods are filling out. Transplanted crops raised in sterile seed or potting compost will have a head start over germinating weed seeds. Methods: “Stale seed bed” technique, Use of herbicides, Organic methods, Thermal methods.
Individual containers with more than one seedling must be thinned to one plant. Pinch out or cut off the extra seedlings while the first leaves are still small. Seedlings germinated in trays must be transplanted to individual containers while still small. Lift and separate seedlings and replant them into individual containers such as peat pots, plastic kalpaks (saved from previously purchased transplants; be sure to wash them), peat pellets, or other small containers. Use a commercial soilless potting mix or prepare your own. Be sure the plants harden off; that is, gradually get used to unsheltered life outdoors. During their last week indoors, withhold fertilizer and water less often.
7 to 10 days before transplanting, set the seedlings outdoors in dappled shade that is protected from winds for a few hours each day, gradually increasing their exposure to full sun and windy conditions. Keep the soil moist at all times during the hardening-off period. Dry air and spring breezes can result in rapid transpiration. If possible, transplant on overcast days or in the early morning. Set transplants into loose, well-aerated soil that will capture and retain moisture, drain well, and allow easy penetration by seedling roots. See when soil is ready for planting. Soak the soil around new seedlings immediately after transplanting. Spread mulch to reduce soil-moisture loss.
To ensure that phosphorus—which promotes strong root development—is available in the root zone of new transplants, mix two tablespoons of a 15-30-15 starter fertilizer into a gallon of water (one tablespoon for vining crops such as melons and cucumbers), and give each seedling a cup of the solution after transplanting. Anything that raises soil temperature will help plants adjust to the shock of cold ground. Try raised planting beds and plastic mulch to boost soil temperature.