Why is my cabbage bolting?

Bolting is usually triggered by rising temperatures or long daylight hours.

Can I grow this in a pot?

Yes, it grows well in containers at least 30 centimeters deep.

Plant guide

Kale.

Brassica oleracea

Pronounced BRASS-ih-kuh oh-ler-AY-see-uh

Also known as Cabbage, Chou Mollier, Haria

cabbage, broccoli, and allies — Photo by rainerburkard (CC BY) via iNaturalist

Kale is a hardy, leafy green that thrives in cooler weather. It is a member of the cabbage family and is prized for its nutritious, ruffled leaves. You can harvest it throughout the season as the plant continues to produce new growth from the center.

At a glance

Care level: Easy
Plant type: Biennial vegetable
Light: Full sun to partial shade
Indoor light: Direct sun
Water: Every 2 to 4 days
Mature size: 1 to 2 feet tall
Growth rate: Fast
Hardiness: USDA 6 to 10
Bloom time: Late spring to early summer

Care

Keep the soil consistently moist and mulch around the base to retain water. Watch for cabbage worms or aphids, which often hide on the undersides of the leaves. Harvest the outer leaves first to encourage the plant to keep growing from the middle.

Watering: Keep the soil evenly moist but not waterlogged.
Feeding: Apply a balanced organic fertilizer every few weeks during the growing season.
Pruning: Remove yellowing or damaged lower leaves to improve air circulation.
Repotting: Kale is typically grown as an annual in the garden, so repotting is rarely needed.
Soil: Well draining, fertile, loamy soil
Soil pH: 6.0 to 7.5
Temperature: -12 to 25°C
Humidity: 40 to 70%
Drought tolerance: Low
Lifespan: Biennial, typically 1 to 2 years
Deer and rabbits: Low

Signs it needs repotting

Roots growing out of the drainage holes.
Water running straight through the pot without soaking in.

Safety

People: The plant is non-toxic, though excessive consumption of raw cruciferous vegetables may affect thyroid function in sensitive individuals.
Pets: Kale is non toxic to cats and dogs.
Children: No specific safety concerns for children, but ensure plants are free of garden pests before handling.
Contact allergens: Some people may experience mild skin irritation from handling the leaves.
Airborne allergens: Pollen from flowering plants can trigger seasonal allergies in sensitive individuals.
Edibility: Always wash leaves thoroughly to remove soil or insect residue before eating.

How to identify it

Ruffled or curly leaf edges
Thick, fibrous central stems
Deep green to purple foliage
Large, rosette shaped growth habit

Height: 0.3 to 0.9m
Spread: 0.3 to 0.6m
Leaves: green, blue-green, purple, evergreen
Flowers: yellow, 1 to 2cm
Fruit: brown, Late summer

Problems to watch for

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: early spring, late summer
Overwintering: In mild climates, it can stay in the garden through winter. In colder areas, cover with mulch or a frost cloth to protect the roots.
In containers: It grows well in containers, provided you use a pot at least 30 centimeters deep with good drainage.

Seed starting

1. Sow seeds 1 centimeter deep in moist soil.
2. Keep the soil warm until germination occurs.
3. Transplant seedlings once they have two sets of true leaves.

Planting aromatic herbs nearby is a great way to confuse pests that look for your vegetables by scent.

Grows well with

Dill · Dill attracts beneficial wasps that prey on cabbage pests.
Onion · The strong scent of onions helps mask the plant from hungry insects.

Keep away from

Strawberry · Strawberries can stunt the growth of brassicas when planted too close.

Similar species

Mustard · It is a close relative with a similar growth habit and culinary use.

Science

Family: Brassicaceae
Genus: Brassica
Order: Brassicales
Class: Magnoliopsida
Native range: Coastal regions of Western and Southern Europe.
Conservation: This species is common and widely cultivated, so it is not of conservation concern.

It thrives in cool, moist coastal environments where it can tolerate salty sea breezes.

Value to wildlife: larval host plant, nectar source
Pollinators: bees, butterflies
Uses: culinary vegetable, ornamental garden plant, cover crop

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 4/9
Soil reaction: 7/9
Light: 7/9
Temperature: 4/9
Nutrients: 8/9
Moisture: 6/9

Taxonomy resolved against GBIF.

Questions people ask

Why is my cabbage bolting?: Bolting is usually triggered by rising temperatures or long daylight hours.
Can I grow this in a pot?: Yes, it grows well in containers at least 30 centimeters deep.

Where the name comes from

The genus name Brassica is the Latin word for cabbage, while oleracea means vegetable or herb used in the kitchen.

Good to know

Brassica oleracea has been cultivated for thousands of years.
The wild form of this plant still grows on limestone cliffs in Europe.
It is incredibly rich in vitamin C and fiber.

Keep your kale growing

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This guide was generated with AI on September 22, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.