How far apart should I plant Kohlrabi?

About 20 cm (8 in) apart, centre to centre. A mature plant spreads 25–40 cm (10–16 in).

Does Kohlrabi need full sun?

Full sun: at least 6 hours of direct sun a day.

How much water does Kohlrabi need?

Moderate water. Drought tolerance is low and waterlogging tolerance low.

How cold-hardy is Kohlrabi?

It tolerates about -8 °C (18 °F) once established, roughly USDA zone 8. As a biennial it is usually planted out after the last frost and flowers in its second year.

When does Kohlrabi flower?

About 54–66 weeks after planting, for 3–5 weeks.

Is Kohlrabi poisonous to cats and dogs?

For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not toxic; like other brassicas it can cause gas if eaten in quantity.

What grows well with Kohlrabi?

Traditional lore says rhubarb planted near brassicas helps against clubroot and pests; the evidence is weak and not confirmed by trials. Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas.

Kohlrabi Brassica oleracea var. gongylodes

Kohlrabi (Brassica oleracea var. gongylodes) is a biennial vegetable in the Brassicaceae family, native to Cultivar group of wild cabbage (coastal Europe). It grows 30–45 cm (12–18 in) tall and 25–40 cm (10–16 in) wide, wants full sun and moderate water, and is hardy to about -8 °C (18 °F). Space plants about 20 cm (8 in) apart.

Plan Kohlrabi in your garden →
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Kohlrabi at a glance

Type	Biennial vegetable
Family	Brassicaceae
Mature height	30–45 cm (12–18 in)
Mature spread	25–40 cm (10–16 in)
Spacing	20 cm (8 in) centre to centre
Sun	Full sun, at least 6 h of direct sun a day
Water	Moderate; drought tolerance low, waterlogging tolerance low
Soil pH	6–7
Cold hardiness	About -8 °C (18 °F) once established (roughly USDA zone 8)
Heat stress	Likely above about 26 °C (79 °F)
Flowering	about 54–66 weeks after planting, for 3–5 weeks
Days to maturity	About 60 days from planting
Wind tolerance	Low
Pollinator value	Low
Edible	Yes: swollen stem (bulb), young leaves
Native to	Cultivar group of wild cabbage (coastal Europe)
Common in gardens of	🇩🇪 Germany, 🇷🇺 Russia, 🇺🇸 United States, 🇬🇧 United Kingdom

Is Kohlrabi toxic?

People: not known to be toxic
Cats: not known to be toxic
Dogs: not known to be toxic

Not toxic; like other brassicas it can cause gas if eaten in quantity.

If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.

Companion planting: what to grow with Kohlrabi

Good neighbours

good With Rhubarb: Traditional lore says rhubarb planted near brassicas helps against clubroot and pests; the evidence is weak and not confirmed by trials. Evidence D
good With Nasturtium: Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas. Evidence C

Shared pests and diseases

Clubroot: Clubroot spores persist in soil up to 20 years; keep brassicas in a rotation. Evidence B

Questions about Kohlrabi

How far apart should I plant Kohlrabi?: About 20 cm (8 in) apart, centre to centre. A mature plant spreads 25–40 cm (10–16 in).
Does Kohlrabi need full sun?: Full sun: at least 6 hours of direct sun a day.
How much water does Kohlrabi need?: Moderate water. Drought tolerance is low and waterlogging tolerance low.
How cold-hardy is Kohlrabi?: It tolerates about -8 °C (18 °F) once established, roughly USDA zone 8. As a biennial it is usually planted out after the last frost and flowers in its second year.
When does Kohlrabi flower?: About 54–66 weeks after planting, for 3–5 weeks.
Is Kohlrabi poisonous to cats and dogs?: For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not toxic; like other brassicas it can cause gas if eaten in quantity.
What grows well with Kohlrabi?: Traditional lore says rhubarb planted near brassicas helps against clubroot and pests; the evidence is weak and not confirmed by trials. Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas.

Sources and evidence

Evidence grade C (C: plausible, mixed evidence).

RHS Plant Finder, Royal Horticultural Society
University extension gardening guides (general), Various land-grant university extensions
EcoCrop crop environmental requirements, FAO

Notes and assumptions

Grown as a spring or autumn crop and harvested in its first year; it flowers only after a winter if left in the ground.

Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.

Related plants

Broccoli Brassica oleracea var. italica
Cauliflower Brassica oleracea var. botrytis
Cabbage Brassica oleracea var. capitata
Kale Brassica oleracea var. sabellica
Radish Raphanus sativus
Bok choy Brassica rapa subsp. chinensis
Brussels sprout Brassica oleracea var. gemmifera
Collard greens Brassica oleracea var. viridis