Kohlrabi

A practical vegetable garden series

 

Grow crisp, mild kohlrabi from seed, and learn when to harvest its swollen stem at its sweetest.

 

Written for home gardeners in Hungary

CHAPTER WELCOME

Your kohlrabi season starts here

This book follows the whole journey: seed → seedling → garden → care → harvest → kitchen → next season.

Kohlrabi is a cool-season vegetable with a curious shape: its stem swells just above the soil into a round, crisp edible part, with leaves growing all around it. The stem may be pale green or purple on the outside, while the flesh inside is usually pale. It has a mild, sweet, cabbage-like flavour and can be eaten raw or cooked. For the best texture, keep it growing steadily and harvest while the swollen stem is still small.

Near Győr, sow outdoors from March or April as soon as the ground is workable, then make small repeat sowings through spring. A second crop can be sown from late July into early August for autumn harvest. Kohlrabi tolerates cool weather and light frost, but heat or dry soil can make it tough, woody or cracked. Water evenly, protect seedlings from cabbage-family pests and harvest at about 5–8 cm across.

Our Hungarian calendar

 

 

The rule for this series: dates guide us, but the plant and the weather make the final decision.

CHAPTER 1

Meet the Kohlrabi

Kohlrabi forms a round swollen stem above the ground, topped with upright leaves.

Kohlrabi (Brassica oleracea var. gongylodes) is a member of the cabbage family. The edible part is a swollen stem that develops above ground, not a root. It can be pale green or purple on the outside, with crisp pale flesh inside. The leaves are also edible when young and tender. Kohlrabi grows best in cool weather and fertile soil with steady moisture. Harvest small for the sweetest, juiciest texture.

Kohlrabi or turnip?

 

Similar names, different plant parts

·  Kohlrabi: the swollen stem forms above the soil and carries the leaves.

·  Turnip: the edible root develops below the soil surface.

·  Green or purple: skin colour varies by variety; flesh is usually pale.

·  The leaves: young leaves can be cooked like other leafy greens.

·  Cool-season crop: spring and autumn help the stem stay crisp.

·  Quick harvest: many varieties mature in roughly 6–10 weeks.

 

CHAPTER 2

Choose Your Kohlrabi

Choose a spring or autumn sowing and decide whether you want green or purple stems.

Ask yourself five questions

1.         Do I have a cool-season window for sowing and growing?

2.         Can I water regularly so the stem grows quickly and stays juicy?

3.         Will I give each plant enough room for its swollen stem?

4.         Can I protect seedlings from cabbage worms and flea beetles?

5.         Will I harvest while the stems are still small and tender?

A beginner-friendly first planting

 

 

 

CHAPTER 3

Let’s Sow

Kohlrabi is easy to grow from seed and is usually sown directly into the garden. It prefers cool weather, and small repeat sowings help spread the harvest. Sow the first short row in early spring once the soil can be worked, then sow again every two or three weeks through spring. Pause during the hottest part of summer and start a fall row in late July or early August.

When to sow in Hungary

Prepare fine, moist soil and sow seeds about 0.5–1 cm deep in short rows. Place seeds roughly 2–3 cm apart, then thin seedlings to about 10–15 cm apart for fresh-eating varieties, following the packet. Leave about 25–30 cm between rows. In Győr County, sow from March or April when the ground is workable; repeat through May or early June. Sow again in late July or early August for an autumn crop. Keep fall seedlings moist in hot weather.

What you need

·  Kohlrabi seeds in a green or purple variety

·  A sunny bed or a roomy, deep container

·  Fine, fertile soil enriched with mature compost

·  A gentle watering can or hose spray

·  Labels and insect mesh or lightweight fleece

Sowing, step by step

1.         Rake the bed smooth and remove weeds and stones.

2.         Make shallow rows and sow seeds about 0.5–1 cm deep.

3.         Cover lightly, water gently and add a label.

4.         Keep the soil moist until seedlings appear, then thin them.

5.         Cover young plants with insect mesh and sow another row later.

 

 

CHAPTER 4

Seedling School

Kohlrabi seedlings grow quickly in cool conditions; give them steady moisture and light.

Recognise young kohlrabi

The seedlings first show two rounded seed leaves, followed by broader true leaves. Keep the soil moist while they establish and thin the row so each plant has room to swell its stem. If you started seeds indoors, harden the seedlings off gradually before planting out. Fine mesh can protect small plants from cabbage worms and flea beetles. Weed gently so you do not disturb shallow roots.

Why is the stem splitting or turning woody?

Kohlrabi can split or become fibrous when growth stops and starts, often because of hot, dry weather followed by heavy watering. Harvest promptly when stems are about 5–8 cm wide, keep soil evenly moist and avoid waiting for spring varieties to become oversized. A little cracking or a rough outer skin does not always mean the inside is unusable; cut it open and check the flesh.

Water while they settle

Water seedlings after sowing or transplanting and keep the soil evenly moist while the plants establish. As the stem begins to swell, water whenever the top few centimetres of soil start to dry. Steady moisture supports rapid, tender growth. Sandy beds, raised beds and containers dry faster than garden soil, so check them more often.

Feeding

Kohlrabi grows well in fertile soil enriched with mature compost. If the bed is poor, apply a balanced vegetable fertiliser according to its label. Avoid high-nitrogen feeding, which can produce lots of leaves without improving the stem. Keep the soil moist and weed-free so the crop can grow steadily.

 

 

CHAPTER 5

Ready for the Real World

Kohlrabi can go into cool spring soil once it is workable, but protect young plants from pests.

Before planting: check the plants and the bed

1.         Choose sturdy seedlings with several true leaves and healthy green growth.

2.         Harden indoor-grown plants off gradually for about a week.

3.         Prepare fertile, moisture-retentive soil that drains freely.

4.         Choose a cool, sunny position with light shade in warm weather.

5.         Have insect mesh ready before cabbage-family pests arrive.

When is it ready in Hungary?

Near Győr, direct sow in March or April as soon as the soil can be worked. Kohlrabi can take some frost, but very cold weather or a long spell of chilly nights may slow young plants. If a hard frost is forecast, cover seedlings. For an autumn crop, sow in late July or early August so plants have time to swell before autumn cold.

Spring weather, soil warmth and frost risk vary across Hungary. In cooler or exposed gardens, wait until the soil is workable and protect very young plants; in warm lowland gardens, sowing can begin earlier. Repeat small sowings through spring for a steady crop, then avoid the hottest weeks. Use the seed packet to check variety-specific timing and spacing.

 

 

CHAPTER 6

Give Them a Good Home

Cool weather, fertile soil and even moisture help kohlrabi stems grow crisp and sweet.

The right place

Choose a sunny position in cool weather, with light afternoon shade if spring or late summer turns hot. Kohlrabi likes fertile, moisture-retentive but well-drained soil. Add mature compost before sowing. Avoid waterlogged beds and places recently used for cabbage-family crops. Keep the bed weed-free while seedlings are small, and place insect mesh over the row early.

Spacing

For fresh-eating varieties, thin plants to about 10–15 cm apart and leave 25–30 cm between rows. Check the packet because compact and giant varieties need different room. Good spacing lets each swollen stem develop, improves airflow and makes harvesting easier. If you thin edible seedlings, use the young leaves in a stir-fry.

Planting day

1.         Water the seedlings and prepare a moist, weed-free bed.

2.         Dig holes at the spacing recommended for your variety.

3.         Set each seedling at the same depth it grew in its pot.

4.         Firm gently, water in well and add a label.

5.         Place insect mesh over the bed and secure the edges.

Growing in pots

Kohlrabi can grow in a deep, wide container with good drainage. Use a pot at least 25–30 cm deep and leave 15–20 cm between plants, or grow one plant in a medium-sized pot. Fill it with fresh potting mix and keep it evenly moist; containers can dry quickly in warm weather. Choose a compact variety and follow the seed packet for the best spacing.

 

CHAPTER 7

Water, Feed & Keep Them Growing

Regular moisture and cool growing conditions help kohlrabi stay tender.

Watering

Water when the soil surface begins to dry, especially while the swollen stems are forming. Kohlrabi needs steady moisture for fast, even growth; drought followed by a heavy soak can lead to cracked or fibrous stems. Water at soil level in the morning and check containers more often. Aim for moist soil, not standing water.

Mulch

Once plants are established, add a light layer of straw or compost around them. Mulch helps reduce weeds and conserve moisture. Keep it away from the stem base and leaves so the plants stay clean and airy. In early spring, wait until the soil has warmed before adding a thick layer.

Feeding

Compost mixed into the bed before sowing is usually a good start. If growth is poor in low-fertility soil, use a balanced vegetable feed as directed. Kohlrabi grows quickly and does not need repeated strong feeds. Too much nitrogen can encourage leafy growth and does not replace regular water.

Keep plants healthy

Check leaves for flea beetles, cabbage worms and slugs, especially when plants are young. Fine insect mesh laid over the row from sowing is an easy way to deter many pests. Remove damaged leaves, keep weeds down and rotate crops: avoid planting kohlrabi where cabbage-family crops grew in the previous three or four years.

 

CHAPTER 8

Stems, Leaves & “What Is That?”

The edible kohlrabi stem swells above the soil, with leaves growing from its sides.

Why is my kohlrabi all leaves and no swollen stem?

The plant may be too young, crowded, stressed or growing in hot weather. Give it time, thin the row to the recommended spacing and keep moisture steady. Kohlrabi forms its swollen stem above the ground, so do not bury it under soil or pile compost against it. If summer heat is slowing the crop, harvest any usable leaves and sow again for autumn.

The beginner’s trouble guide

 

 

 

CHAPTER 9

Can I Pick It Yet?

Yes—harvest kohlrabi when the swollen stem is about 5–8 cm wide and still feels firm.

What “ready” looks like

Look for a firm, rounded swollen stem about 5–8 cm across for most fresh-eating varieties. It should feel crisp and juicy, not soft or woody. Spring stems are best picked small because they can turn fibrous in warm weather; some fall and giant varieties can grow larger if the packet says they keep their quality. Cut the stem at soil level and use the leaves while they are fresh.

Harvest from spring into autumn

 

How often should I check?

Check the row every few days once the stems begin to swell. Harvest plants as they reach the size you want rather than waiting for every plant to be ready together. Small repeat sowings give several harvests through spring and autumn. Remove leaves after picking and refrigerate the stems; young leaves can be cooked like greens.

 

 

CHAPTER 10

From the Garden to the Kitchen

Kohlrabi has a crisp, mild flavour and can be eaten raw or cooked.

The first rule: peel mature stems

Wash the stem and trim off the leaves and their stalks. Young, tender kohlrabi can be eaten with its skin if it is clean and thin; peel larger or tougher stems with a vegetable peeler or knife. Slice it raw into sticks, grate it into slaw, or cut it into cubes for a stir-fry, soup or roast vegetable tray. The leaves are edible too: rinse them well and cook them like kale or spinach.

Match kohlrabi to the dish

·  Raw: cut young stems into sticks or thin slices.

·  Slaw: grate peeled kohlrabi with apple or carrot.

·  Stir-fry: add sliced stems and tender leaves.

·  Roasted: cut into cubes and roast until browned.

 

Storing fresh kohlrabi

Remove leaves from the stem before storing, since they draw moisture from it. Keep unwashed stems in a perforated bag in the refrigerator for about two weeks. Store the leaves separately in a damp paper towel and use them within a few days. Wash just before preparing. Discard stems that are mouldy, soft or badly cracked.

When you have more than you can use

Kohlrabi keeps best fresh and cool. If you have a larger harvest, peel and cut the stems into small pieces, blanch briefly, cool quickly and freeze in labelled portions. Tender leaves can be cooked and frozen separately. Harvest spring varieties while they are small instead of leaving them in the bed until they become woody.

CHAPTER 11

Next Season Starts Now

A few notes about sowing, watering and harvest size will help you plan next year’s kohlrabi crop.

Keep a tiny garden record

·  Seed source and exact kohlrabi variety

·  Date of each sowing and when seedlings appeared

·  Whether spring or autumn sowing gave the best crop

·  How watering and spacing affected the stems

·  When the first swollen stems were ready

·  Which varieties stayed tender at harvest

·  Which sowing dates avoided summer heat

Saving seed and planning another crop

Kohlrabi is a biennial: it usually forms its edible stem in the first year and flowers in the second after a cold period. Saving seed takes space and time, and kohlrabi can cross-pollinate with other Brassica oleracea crops such as cabbage, kale, broccoli and cauliflower. Seed saved from hybrid varieties may not come true. For dependable results in a small garden, buy fresh seed each year.

1.         Choose a healthy plant of an open-pollinated variety.

2.         Keep it through winter and let it flower in the second year.

3.         Allow seed pods to mature and dry on the plant.

4.         Collect dry pods and finish drying them in a warm, airy place.

5.         Label the variety and year, then store cool and dry.

 

 

COME GROW WITH ME

KOHLRABI CHEAT SHEET

The page to come back to when you have soil on your hands and no time to reread the whole book.

 

 

 

COME GROW WITH ME • KOHLRABI

Seasonal guidance is adapted for Hungarian home gardens.