Kohlrabi Seeds

Why Grow Kohlrabi?

Kohlrabi Seeds for Different Growing Goals

White Vienna and Purple Vienna have similar growing requirements but provide different external colours and market presentation.

White Vienna vs Purple Vienna Kohlrabi

The main visible difference between White Vienna and Purple Vienna is the colour of the outer stem. Their edible interiors and general culinary uses are similar.

What Is Kohlrabi?

Kohlrabi is a cultivated brassica related to cabbage, broccoli, kale and cauliflower. Its botanical name is Brassica oleracea var. gongylodes.

The plant produces a rounded or slightly flattened swollen stem immediately above the soil surface. Leaves extend from this enlarged stem on upright stalks.

The name kohlrabi comes from words associated with cabbage and turnip, which explains why it is often called German turnip. However, kohlrabi is not a true turnip and does not form its edible portion below the ground.

Is Kohlrabi a Turnip, Cabbage or Root Vegetable?

Kohlrabi is a form of Brassica oleracea, the same species that includes cabbage, broccoli, cauliflower, Brussels sprouts and kale.

It is not a true turnip. Turnips belong primarily to Brassica rapa and develop enlarged roots partly or completely beneath the soil.

Kohlrabi is commonly grouped with root vegetables in cooking because its swollen stem is firm and can be prepared similarly to turnip or potato. Botanically, however, the edible bulb is an above-ground stem.

What Does Kohlrabi Taste Like?

Kohlrabi has a mild, fresh and slightly sweet flavour. Its crisp flesh is often compared with broccoli stem, cabbage heart, turnip or a mild radish without strong heat.

Flavour and texture vary with harvest stage and growing conditions.

How to Grow Kohlrabi in Australia

Kohlrabi is best grown through cool to mild weather. It requires full sun or strong light, fertile free-draining soil and consistent moisture to develop smooth, tender swollen stems.

When to Plant Kohlrabi in Australia

Kohlrabi is generally planted from late summer through autumn or during suitable spring conditions. The best period depends on local heat, frost and the length of the mild growing season.

These sowing periods are general guides. Local frost dates, elevation, seasonal heat, rainfall and irrigation availability should also be considered.

When to Plant Kohlrabi in Australian States and Cities

Planting periods should be adjusted according to local climate and whether the crop will mature during cool, mild or hot conditions.

How to Grow Kohlrabi from Seed

Kohlrabi can be direct-sown into prepared soil or raised in trays and transplanted while young. Direct sowing reduces root disturbance, while tray production allows better control of spacing and early pest protection.

1. Choose a suitable planting period.
   Plan the crop so the swollen stems develop during cool to mild conditions.
2. Prepare fertile, free-draining soil.
   Remove weeds and improve the bed with suitable organic matter where required.
3. Sow the seed shallowly.
   Plant approximately 5–10 mm deep and cover lightly.
4. Maintain consistent moisture.
   Keep the seedbed moist without leaving it waterlogged.
5. Thin or transplant seedlings.
   Provide final spacing before plants become crowded or root-bound.
6. Protect young plants.
   Monitor for slugs, snails, caterpillars and other common brassica pests.
7. Water steadily.
   Avoid prolonged dry periods while the swollen stems are developing.
8. Harvest at the correct size.
   Pick while stems remain tender rather than waiting for maximum size.

How Deep Should Kohlrabi Seeds Be Planted?

Plant kohlrabi seeds approximately 5–10 mm deep. Cover them lightly with fine soil or seed-raising mix.

How Long Do Kohlrabi Seeds Take to Germinate?

Kohlrabi seeds commonly germinate within approximately 5–10 days under suitable conditions. Cold, dry or waterlogged soil may delay emergence.

Can Kohlrabi Seedlings Be Transplanted?

Yes. Kohlrabi is commonly raised in trays and transplanted after developing several true leaves.

Harden seedlings gradually before moving them outdoors. Plant during mild conditions and maintain the same approximate depth they occupied in the tray.

Do not allow seedlings to become severely root-bound. Interrupted early growth can reduce final stem size or encourage premature flowering.

How Far Apart Should Kohlrabi Be Planted?

Spacing affects the final size of the swollen stem, airflow and the number of plants that can be grown in a bed.

How Long Does Kohlrabi Take to Grow?

Kohlrabi commonly produces harvestable swollen stems within approximately 50–75 days from sowing. The exact time depends on variety, temperature, planting density, soil fertility and intended harvest size.

Growing times are general guides. Review individual product pages for variety-specific maturity information.

Growing Kohlrabi in Pots and Containers

Kohlrabi can grow successfully in pots, troughs and raised planters because it is more compact than many heading brassicas.

Can Kohlrabi Grow in Shade?

Kohlrabi performs best in full sun during cool weather. It can tolerate light partial shade, particularly in climates where afternoon temperatures become warm.

Deep shade can produce elongated plants, weak stems and reduced swelling. Provide several hours of strong direct or filtered light each day.

Watering and Feeding Kohlrabi

Kohlrabi requires steady moisture and adequate fertility to develop smooth, tender stems.

Water deeply enough to moisten the active root zone. Avoid alternating between severe dryness and heavy saturation.

Mulching around established plants can help:

• Reduce moisture loss
• Moderate soil temperature
• Limit weed competition
• Protect the soil surface from crusting

Kohlrabi responds to balanced fertility. Excessive nitrogen can promote large leaves without proportionate stem development, while inadequate fertility can result in small, slow-growing plants.

When to Harvest Kohlrabi

Harvest kohlrabi when the swollen stem reaches the preferred size but remains firm, smooth and tender.

Vienna varieties are commonly harvested when the stem is approximately 5–8 cm in diameter. Smaller stems are generally tender, while oversized plants may become fibrous or woody.

Signs of harvest readiness include:

• The stem has developed a rounded or slightly flattened shape
• It has reached the expected diameter for the variety
• The skin remains smooth and firm
• The plant has reached its approximate maturity period
• A test stem has crisp, tender internal flesh

How to Harvest Kohlrabi

Use a clean, sharp knife or secateurs to cut the plant at or just below soil level.

Remove the roots and trim away damaged outer leaves. Healthy young leaves may be retained for cooking or fresh-market presentation.

Do not attempt to pull large plants forcefully from compacted soil, as the stem or leaves may break.

Does Kohlrabi Grow Back After Harvest?

Kohlrabi does not usually produce another full-sized swollen stem after the main stem is harvested.

If the entire stem is cut above the lowest leaves, the remaining plant may produce small leafy shoots. These can sometimes be used as greens, but they should not be expected to form a second crop equivalent to the original kohlrabi.

For a continued harvest of swollen stems, make successive seed sowings.

Are Kohlrabi Leaves Edible?

Yes. Kohlrabi leaves and tender leaf stems are edible. They have a brassica flavour and can be used similarly to kale, cabbage greens or young broccoli leaves.

Young leaves are generally more tender than large mature foliage.

Suitable uses include:

• Steaming
• Sautéing
• Stir-frying
• Adding to soups
• Using young leaves in mixed salads
• Cooking with garlic, olive oil or spices

Avoid removing too many leaves from plants still being grown for large swollen stems, as the foliage is needed for continued growth.

Can Kohlrabi Be Eaten Raw?

Yes. Young kohlrabi is commonly eaten raw because of its crisp texture and mild flavour.

Remove leaves and trim the base. Peel the outer skin where it is tough, then slice, grate or cut the flesh into sticks.

Raw kohlrabi can be used in:

How to Prepare and Cook Kohlrabi

Remove the leaves and trim the base and upper stalks. Wash the swollen stem thoroughly.

Young kohlrabi may have tender skin, while larger stems generally benefit from peeling. Use a vegetable peeler or knife to remove any firm or fibrous outer layer.

Kohlrabi can be:

Does Kohlrabi Need to Be Peeled?

Small young kohlrabi may have sufficiently tender skin to eat without peeling. Larger stems often develop a firmer, fibrous outer layer that should be removed.

Peel when:

• The outer skin feels tough or leathery
• The stem is larger or more mature
• The base contains visible fibrous tissue
• The kohlrabi will be eaten raw
• A smooth texture is required for mashing or soups

Cut a small test section after peeling. If fibres remain beneath the skin, remove an additional thin layer.

How to Store Kohlrabi

Remove the leaves before storing the swollen stems because attached foliage continues drawing moisture from them.

Store clean, dry kohlrabi in the refrigerator. Keep the leaves separately and use them promptly.

For longer storage:

• Do not wash stems until shortly before use where possible
• Remove damaged or decaying material
• Store in a suitable produce bag or container
• Maintain cool conditions without freezing
• Check periodically for softening or deterioration

Kohlrabi may also be blanched and frozen using an appropriate food-preservation method.

Common Kohlrabi Growing Problems

How to Protect Kohlrabi from Caterpillars

Kohlrabi can be attacked by cabbage white butterfly caterpillars, cabbage moth larvae and other brassica pests.

Protection methods include:

• Covering plants with fine insect netting
• Checking the undersides of leaves for eggs
• Removing visible caterpillars where practical
• Keeping weeds around the crop controlled
• Using only legally registered crop-protection products according to their labels
• Rotating brassica crops where possible

Protect the central growing point carefully. Severe damage while plants are young can prevent normal swollen-stem development.

What to Plant with Kohlrabi

Kohlrabi can share beds with vegetables that have compatible seasonal, moisture and spacing requirements.

Potential neighbouring crops include:

• Lettuce and compact salad greens
• Onions and spring onions
• Beetroot
• Carrots where sufficient root space is maintained
• Peas
• Celery
• Selected herbs and flowers around bed edges

Other brassicas have similar seasonal requirements but can concentrate caterpillars and soil-borne diseases. Maintain appropriate crop rotation.

Packet and Bulk Kohlrabi Seeds

Important Considerations for Commercial Growers

Commercial kohlrabi production requires varieties and planting dates suited to the required stem size, colour and market window.

Frequently Asked Questions