Crop rotation should be observed for cabbage farming in Kenya as the crop uses too many nutrients from the soil in a single growing season.
The land, which should have access to plenty of sun and be well drained, must be prepared well in advance – preferably some weeks before planting the seedlings.
Land should be nutrient-rich and well tilled to a depth of at least six inches. Loosen soil in the planting bed and mix in a two-inch layer of compost along with a standard application of a balanced organic fertilizer or manure.
Seed selection and seedlings
Select the best variety of seed – many beginner cabbage farmers in Kenya fail at this stage. The seedling process is the most important part of cabbage growing. If starting with seeds start 7 weeks or so before the last expected frost. Transplant the seedlings when they are 4 to 6 weeks old.
During transplantation of cabbage seedlings ensure that all cabbage plants get started in the same fashion for proper growth of plants. Transplantation is recommended when seedlings are 3 inches tall. Plants should be planted deep in holes fed with lose soil.
The plants should be well spaced as they can grow quite large. A cabbage head can weight as much as 6 kilograms. Spacing of 18 inches between holes and 2 feet between rows is just about ideal. Soil around the plant should be tamped and about half the seedling left visible above ground level.
The plants must be protected from insects by timely spraying of pesticides. Regular watering is highly recommended as the crop should never be stressed.
When the plants are about 6 inches tall, a layer of mulch or grass clippings, straw and chopped up leaves should be applied around plants to keep the soil cool and moist. This would also discourage weeds from growing around the cabbages.
After harvesting the applied organic materials can be tilled into the soil and add nutrients to the garden.
Cabbage farming demands regular weeding as soon as the undesirable weeds are visible.
Cabbage plants need 6-8 hours sunlight per day. Most varieties take some 45-100 days to harvest after planting. Larger cabbage head varieties take longer to mature. Temperatures averaging between 60-70 degrees celsius are ideal for the crop, though an established crop can endure temperatures dipping into freezing levels at night.
Prolonged daily temperatures of over 35 degrees Celsius may cause the crop to stop growing.
At the early stages if there are frost warnings at night farmers would be advised to cover plants with a plastic sheet over night and expose them to sun the following day.
Fertilizing and watering
Cabbage is a heavy feeder crop and requires a lot of water and fertilizer. Lack of food would stunt their growth leading to undersized heads. Water is used by cabbage to absorb nutrients from the soil. Since cabbage is mainly made up of water, without enough watering its head would dry out and become bitter.
If the area is not receiving sufficient rains the cabbages should be treated to a once a week heavy watering, which sinks deep into the soil as cabbage roots run deep.
Water pressure should be kept low when watering to avoid eroding away the soil. Avoid watering the top of the cabbage head as it can encourage pests and diseases. Early morning watering is advisable and it should be re-emphasised that cabbage is a thirsty plant which needs a lot of water.
Since cabbage is a heavy feeder it is recommended that plants are treated to doses of fertilizer throughout the growing season. Fertilizer can be added to the soil just before transplanting cabbage seedlings and sprinkle another dosage on the area where the seedlings are to be planted. Work it well into the soil.
When the plants are some 6 inches tall the farmer should fertilize the cabbage again with water soluble fertilizer, since granular fertilizer will burn the cabbage plant if it comes into direct contact with the leaves.
Another dose of water soluble fertilizer should be applied when the seedling starts developing a cabbage head. The fertilizer will energize the plants to produce large and well formed heads.
Before harvesting the farmer should test the ripeness of the cabbage by squeezing it firmly. When ripe the cabbage head will be firm and not give in much to the applied pressure.
A sharp knife should be used to cut off the cabbage head from its stem. The cutting should be just below the cabbage head and the stem must remain in its position. If the weather is favourable another cabbage head can develop on the stem as a bonus to the farmer. After harvesting the plants can be pulled up and turned into compost.
Seed Rate: 120g/ Acre
Yield: 10,000-15,000 heads/ Acre (Around 20 tons)