Crop details

Kale / Collard (sukuma wiki)

Brassica oleracea var. acephala

Family: Brassicaceae

Quick stats

Family	Brassicaceae
Typical harvest	23.0 t/ha
Varieties	3
Pests & diseases	7
Seasons	3

Crop profile

Growth habit	annual
Days to harvest	120
Main uses	Leaves cooked as vegetables, often fried or boiled and eaten with ugali or other staples.
Pollination	insect
Origin / where it grows	Kale / Collard (sukuma wiki) is one of the most common leafy vegetables around homes, towns and irrigation schemes across East Africa.

Weather, soil & spacing

Best temperature	15–22 °C
Rainfall	600–900 mm/yr
Altitude	800–2600 m
Best pH	6.2–6.8
Soil type	Deep, fertile, well-drained loam or sandy loam rich in organic matter so Kale / Collard (sukuma wiki) can keep producing leaves.
Row spacing	60 cm
Plant spacing	45 cm
Planting depth	1.5 cm
Seed rate	0.5 kg/ha
Nursery days	30

Simple notes for farmers

About the crop: This crop is annual. You plant, grow and harvest it in one main season, then plant again. You can normally start harvesting about 120 days after planting, depending on care and variety.

Main use: Farmers mostly grow this crop for leaves cooked as vegetables, often fried or boiled and eaten with ugali or other staples..

Pollination: This crop is mainly pollinated by insect. Keeping flowers healthy and having insects like bees in the field helps improve fruit set and yields.

Where it grows: Kale / Collard (sukuma wiki) is one of the most common leafy vegetables around homes, towns and irrigation schemes across East Africa. It is grouped under: Vegetables.

Best climate: This crop does well in warm areas where the temperature is usually between 15 and 22 degrees Celsius. It prefers places that receive around 600 to 900 millimetres of rain in a year. It can grow from near sea level up to about 2600 metres above sea level.

Soil: The crop grows best in slightly acidic to near neutral soils, with a pH of about 6.2 to 6.8. It does well in deep, fertile, well-drained loam or sandy loam rich in organic matter so kale / collard (sukuma wiki) can keep producing leaves.. Good drainage is important, so avoid waterlogged spots.

Plant spacing: Plant in rows about 60 centimetres apart, and leave about 45 centimetres between plants in the row. This gives each plant enough space for roots and canopy to spread.

Planting depth: Dig planting holes or furrows about 1.5 centimetres deep so the roots sit firmly in the soil but are not buried too deep.

Seed or planting material: Use around 0.5 kilograms of seed or planting material per hectare. Spread or plant evenly so the field has a good stand without being overcrowded.

Nursery period: If you raise seedlings in a nursery, keep them there for about 30 days before transplanting to the main field, when they are strong and healthy.

Farmer guide (mwongozo wa mkulima)

Planting: Sow Kale / Collard (sukuma wiki) seed in a small nursery bed or trays using fine soil and compost. Keep moist and shaded during hot hours. Transplant strong seedlings with 4–6 true leaves into well-prepared beds.

Transplanting: Water nursery before lifting seedlings. Transplant in the late afternoon or on cloudy days. Plant at the same depth as in the nursery and firm the soil gently around the roots, then water.

Irrigation: Keep soil consistently moist for fast leaf growth. Avoid long dry spells which cause tough leaves and early yellowing.

Fertigation: Under drip, give small regular doses of NPK. Kale / Collard (sukuma wiki) responds well to nitrogen but balance with potassium and calcium to avoid soft, weak plants.

Pest scouting: Check sukuma wiki at least once a week for caterpillars, diamondback moth, aphids and leaf spots. Look at both sides of the leaves and in the growing point.

Pruning: No pruning needed; just remove yellow, damaged or diseased leaves and destroy them. Harvest outer leaves and leave the centre to keep growing.

Harvest: Start picking outer leaves when plants are well established. Always leave some leaves on each plant so Kale / Collard (sukuma wiki) can keep producing for many months.

Postharvest: Harvest in the cool hours. Keep leaves in shade, sprinkle clean water lightly if wilting and transport in clean crates or sacks with air holes.

Nutrient schedule (mbolea kwa hatua)

#	Stage	DAP	Product	Rate	Targets (kg/ha)	Notes
1	Basal at transplanting	0	NPK 17-17-17 or 15-15-15	250 kg/ha	N: 42, P₂O₅: 42, K₂O: 42	Band fertilizer 5–8 cm away from the sukuma wiki row and cover lightly with soil.
2	Early topdress	21	CAN 26% N	100 kg/ha	N: 26, P₂O₅: 0, K₂O: 0	Apply between rows when soil is moist; irrigate or lightly incorporate.
3	Topdress after first harvests	45	Urea 46% N or CAN + SOP	80 kg/ha	N: 30, P₂O₅: 0, K₂O: 20	Supports continuous leaf production of Kale / Collard (sukuma wiki). Repeat smaller doses based on crop colour and vigour.

Nutrient requirements

Nutrient	Stage	Amount	Unit
N	Basal	50	kg/ha
P₂O₅	Basal	60	kg/ha
K₂O	Basal	60	kg/ha
N	Topdress_early	50	kg/ha
P₂O₅	Topdress_early	0	kg/ha
K₂O	Topdress_early	40	kg/ha
N	Topdress_after_pickings	40	kg/ha
P₂O₅	Topdress_after_pickings	0	kg/ha
K₂O	Topdress_after_pickings	40	kg/ha

Name	Country	Maturity	Traits
Sukuma wiki local	KE	75	Traditional type, tolerant and widely adapted, moderate yield.
Improved collard-type sukuma wiki	KE	80	Broad leaves, good regrowth and higher yield with good management.
Hybrid kale/collard	TZ	80	Uniform plants, dark green leaves and good market quality.

Stage	Product	Rate (kg/ha)	Notes
Basal	NPK 17-17-17 or 15-15-15	250	Gives balanced nutrients for early sukuma wiki growth.
Topdress (N source)	CAN 26% N or urea	100	Apply one or two times during vegetative growth and regrowth.
Topdress (K source)	Sulfate of potash (SOP) or high-K NPK	80	Improves leaf quality and strength.
Organic	Well-rotted manure or compost	8000	Apply before planting to boost soil organic matter and water holding.

Name	Type	Symptoms	Management
Diamondback moth	pest	Small green caterpillars making small windows and holes in Kale / Collard (sukuma wiki) leaves, often starting in nurser...	Use netting on nurseries, destroy crop residues, rotate with non-cabbage crops and use Bt or other selective insecticide...
Cutworms	pest	Seedlings or young sukuma wiki plants cut at or just above ground level.	Prepare land early, control weeds and apply spot treatments or baits if damage is high.
Aphids	pest	Clusters of small insects on young leaves and stems of Kale / Collard (sukuma wiki), curling leaves and sticky honeydew.	Encourage natural enemies, wash off with water jets on small plots and use selective insecticides/biopesticides when sev...
Flea beetles	pest	Many small round holes, mainly on young leaves of sukuma wiki; leaves look shot-holed.	Keep nursery and field weed-free, use fine netting on nurseries and apply recommended insecticides if necessary.
Black rot	disease	Yellow V-shaped patches on edges of Kale / Collard (sukuma wiki) leaves, dark veins and stunted plants.	Use clean seed, avoid overhead irrigation late in the day and rotate with non-brassica crops.
Downy mildew	disease	Yellow patches on upper leaf surface with grey-white mould underneath, especially in cool, wet conditions.	Improve air circulation, avoid overcrowding and use protectant fungicides when conditions favour disease.
Alternaria leaf spot	disease	Dark spots with concentric rings on leaves of Kale / Collard (sukuma wiki), leading to leaf drop.	Remove infected leaves, avoid overhead irrigation where possible and use fungicides when necessary.

System	Typical	Min	Max	Notes
Backyard / low-input sukuma wiki	12	8	15	Small amounts of manure, little fertilizer, irregular picking and basic pest control.
Open-field Kale / Collard (sukuma wiki), improved management	22	15	30	Good varieties, regular picking, recommended fertilizer and good pest management.
Irrigated, high-input sukuma wiki	35	25	45	Continuous picking with irrigation, fertigation and strong pest and disease control.

Country	Region	Planting	Harvest
KE	Highland and peri-urban sukuma wiki zones (rainfed)	Most of the year where moisture is available	First picking from about 6–8 weeks after transplanting, then regular harvests.
KE	Irrigated Kale / Collard (sukuma wiki) belts	Any time with reliable water	Continuous pickings for several months.
TZ	Highland and mid-altitude vegetable zones	Cooler, moist periods or with irrigation	Multiple pickings starting 1½–2 months after transplanting.

Country	Region	Suitability
KE	Highland and mid-altitude vegetable belts	High
KE	Peri-urban areas near towns	High
KE	Very hot, dry lowlands without irrigation	Low
TZ	Highland and irrigated Kale / Collard (sukuma wiki) areas	High
UG	Mid- to high-altitude vegetable-growing zones	High