Kale
Brassica oleracea var. sabellica
Hardy brassica whose flavor actually improves after a light frost. Rich in vitamins and minerals, harvestable well into winter.
Overview
Companion Planting
Good Companions
Beetroot
Celery
Onion
Nasturtium
MarigoldBad Companions
StrawberryToxicity
Safe for humans in normal amounts; may cause thyroid issues if consumed raw in excess. Can cause Heinz body anemia in cats. Safe for dogs in small quantities but large amounts may cause GI upset.
Planting Tips
1 cm of water per m² equals 10 liters. Use the Watering Calculator for exact amounts.
Care Tip: Mulch around plants to retain moisture, suppress weeds, and keep roots cool; harvest outer leaves first to encourage continued growth.
Common Pests
Aphids
Symptoms: Clusters of tiny green, black, or gray insects on leaf undersides; leaves curl, yellow, and growth becomes stunted.
Treatment: Blast with a strong jet of water; apply insecticidal soap or neem oil for persistent infestations.
Prevention: Plant aromatic herbs like dill, mint, or rosemary nearby to repel aphids; encourage beneficial insects such as ladybugs.
Cabbage Worms
Symptoms: Ragged, irregular holes in leaves with greenish-brown frass; small velvety green caterpillars visible on foliage.
Treatment: Handpick caterpillars daily; spray Bacillus thuringiensis (Bt) for organic biological control.
Prevention: Use floating row covers to block adult white cabbage moths from laying eggs; inspect leaf undersides regularly.
Flea Beetles
Symptoms: Numerous tiny round holes (shot-holes) scattered across leaves; seedlings may be stunted or killed.
Treatment: Apply neem oil or spinosad; dust plants with kaolin clay or diatomaceous earth.
Prevention: Use floating row covers on young plants; delay transplanting until temperatures exceed 10 °C; plant nasturtiums as a trap crop.
Common Diseases
Downy Mildew
Symptoms: Angular yellow lesions on upper leaf surfaces with gray-white fuzzy spore growth on undersides; lesions enlarge and turn necrotic.
Treatment: Remove and destroy affected leaves; apply copper-based fungicides preventatively; improve air circulation around plants.
Prevention: Rotate away from brassica crops for at least 3 years; avoid overhead irrigation and reduce planting density.
Black Rot
Symptoms: V-shaped yellow-to-brown lesions at leaf margins with darkened (blackened) veins; internal stem discoloration.
Treatment: Remove and destroy infected plants immediately; no reliable cure once established — focus on prevention.
Prevention: Use certified disease-free or hot-water-treated seed (50 °C for 20 min); rotate cruciferous crops on a 3-year cycle; avoid working in wet foliage.
Clubroot
Symptoms: Swollen, distorted roots; plants wilt on warm days, become stunted, and leaves yellow due to impaired nutrient uptake.
Treatment: No effective chemical treatment; remove and destroy infected plants and do not compost them.
Prevention: Maintain soil pH above 7.0 by liming; rotate away from all brassicas for 5-7 years after an outbreak; improve soil drainage.