When to Harvest Kohlrabi (Timing, Signs, and How to Pick)

Timing the kohlrabi harvest is the difference between a tender, sweet bulb and a woody, fibrous disappointment. Harvest too early and you get a marble-sized bulb with minimal flesh. Harvest too late and the flesh turns tough, stringy, and bitter. The window is narrower than you might think.

The good news: kohlrabi gives clear signals when it’s ready. Once you know what to look for, you won’t second-guess yourself.

The Short Answer

Harvest most kohlrabi varieties when the bulb (the swollen stem above the soil) reaches 2 to 3 inches in diameter — roughly the size of a tennis ball. This typically happens 45 to 65 days after transplanting or 55 to 75 days after direct sowing, depending on the variety and growing conditions.

Giant varieties like ‘Superschmelz’ or ‘Kossak’ are the exception — they can grow to 8-10 inches across and still stay tender. More on those below.

How to Tell When Kohlrabi Is Ready

Size is the primary indicator, but not the only one.

1. Check the Diameter

The most reliable method. Measure across the widest part of the bulb, or compare it to something you know:

• Golf ball (1.7 inches): Too early for most varieties. The bulb is developing but hasn’t reached full size. Wait.
• Tennis ball (2.5 inches): Ideal harvest size for standard varieties. The flesh should be tender and sweet.
• Softball (3.8+ inches): Getting late for standard varieties. The outer layer may be turning fibrous. Harvest immediately.

For practical purposes: when the bulb looks like it’s stopped growing rapidly and has reached about 2-3 inches across, it’s time.

2. Feel the Surface

Press the bulb gently with your thumb. A harvest-ready kohlrabi feels firm but gives very slightly — similar to pressing a ripe apple. If it feels rock-hard with no give at all, it may be overmature and woody inside.

The skin should feel smooth. If you can feel ridges, cracks, or a noticeably rough texture, the bulb has likely grown past its prime.

3. Check the Leaves

Healthy, actively-growing leaves suggest the bulb is still developing. When the lower leaves start yellowing while the bulb has reached size, that’s a confirmation signal that the plant has put its energy into the bulb and is approaching maturity.

However, don’t wait for the leaves to yellow as your primary indicator — by then the bulb may already be past its peak. Use leaf condition as a secondary check.

4. Look at the Color

The bulb’s color should be consistent with its variety — light green, white, or purple, depending on what you planted. If a green or white variety starts showing brown patches, woody-looking skin, or the purple varieties lose their vibrancy, those are signs of over-maturity.

Timing by Variety

Different kohlrabi varieties mature at different rates. Knowing your variety helps you plan.

Early Varieties (40-55 days from transplant)

• ‘Early White Vienna’ — The most common variety. Quick to mature, best harvested at 2-2.5 inches.
• ‘Early Purple Vienna’ — Purple-skinned version. Same timing as Early White. The purple is only skin-deep; the flesh is white.
• ‘Quickstar’ — Bred for speed. Can be ready in as few as 38 days from transplant.
• ‘Winner’ — Early, uniform, and resistant to becoming woody even if you’re a few days late.

Mid-Season Varieties (55-65 days from transplant)

• ‘Kolibri’ — Purple hybrid. Slightly larger than the Vienna types. More forgiving harvest window.
• ‘Kongo’ — Green hybrid, good uniformity. Harvest at 3 inches.
• ‘Grand Duke’ — Reliable, crack-resistant, and stays tender slightly longer than average.

Giant Varieties (70-130 days from transplant)

• ‘Superschmelz’ — The famous giant. Can grow to 10+ inches and 8-10 pounds while remaining tender. Harvest anywhere from 4 to 10 inches.
• ‘Kossak’ — Another giant that stays tender at large sizes. Harvest at 6-8 inches for best quality.
• ‘Gigante’ — Similar to Superschmelz. Bred for large size without woodiness.

Giant varieties are specifically bred to maintain tender flesh as they grow. Don’t apply the “2-3 inch rule” to these — that would be harvesting them as babies. Let them size up.

For more on variety selection, see our kohlrabi varieties guide.

Seasonal Timing

Kohlrabi is a cool-season crop, and when you plant it determines when and how you harvest.

Spring Planting

Plant transplants outdoors 2-4 weeks before the last frost date. Spring kohlrabi matures in warming conditions, which accelerates growth. The risk is that a sudden heat wave pushes the plants to bolt (send up a flower stalk) before the bulb fully develops.

Harvest window: Typically late spring to early summer. Don’t delay — rising temperatures encourage woodiness. Harvest as soon as bulbs reach size. A few days late in hot weather makes more difference than a few days late in cool weather.

Fall Planting

Direct sow or transplant in late summer, timed so the bulbs mature during the cooling days of autumn. Fall-grown kohlrabi is generally sweeter and more tender than spring-grown because cool nights enhance sugar content. A light frost doesn’t hurt kohlrabi — it actually improves flavor.

Harvest window: Mid to late autumn. You have more flexibility here because cooling temperatures slow growth and delay woodiness. If a hard freeze (below 25°F / -4°C) is forecast, harvest everything beforehand.

Succession Planting

For a continuous harvest, sow new seeds every 2-3 weeks from early spring through late summer. This gives you fresh kohlrabi coming in on a rolling basis rather than a single large harvest. For more growing strategies, see our kohlrabi growing guide.

How to Harvest Kohlrabi

The actual picking process is straightforward. Kohlrabi grows above the soil surface, so you’re not digging anything up.

Method 1: Cut at the Base (Recommended)

1. Grasp the bulb firmly with one hand.
2. Using a sharp knife or garden scissors, cut the stem about 1 inch below the bulb, at the soil line.
3. Trim off the leaves. If the leaves are fresh and green, save them — kohlrabi leaves are edible and nutritious.

This method is clean and doesn’t disturb surrounding plants.

Method 2: Pull

For loose or sandy soil, you can simply grasp the bulb and pull the entire plant out of the ground.

1. Grip the bulb (not the leaves — they’ll tear).
2. Rock it gently side to side while pulling upward.
3. Shake off excess soil and trim the root and leaves.

This works fine but can disturb neighboring plants if they’re spaced closely. Cutting is gentler.

Harvesting the Leaves

Kohlrabi leaves are edible at any stage, and you don’t have to wait for the bulb to mature to harvest them. You can pick individual outer leaves throughout the growing season as a cut-and-come-again green. Just leave at least 4-5 inner leaves on the plant so it can continue photosynthesizing and feeding the bulb.

When you harvest the whole plant, cut the leaves where they join the bulb. Use them the same day if possible — kohlrabi greens wilt faster than the bulb degrades.

What Happens If You Harvest Too Late

Over-mature kohlrabi isn’t dangerous to eat, but it’s unpleasant. Here’s what happens:

The outer layer turns woody. A thick, fibrous rind develops around the outside of the bulb. You can peel this off, but it wastes a significant portion of the flesh.

The interior becomes stringy. Fibers develop through the flesh, creating a texture like chewing on wood shavings. This is most pronounced in the outer portions of the bulb but can extend toward the center in severely overgrown specimens.

The flavor turns bitter. Kohlrabi’s mild sweetness gives way to a harsher, more cabbage-like bitterness. Cooking can mask some of this, but it doesn’t fix the texture problem.

Cracking. Overgrown bulbs, especially those that received inconsistent watering, can develop cracks or splits. These aren’t a food safety issue but reduce storage life.

Can You Salvage Overgrown Kohlrabi?

Sometimes. If the bulb is overgrown but not drastically so (say, 4 inches for a standard variety), peel away the tough outer layer until you reach tender flesh. The inner portion may still be usable. Cut a thin slice and taste it — if it’s not fibrous or bitter, use it.

For truly overgrown bulbs that are woody throughout, your best option is to slice them thin, boil until soft, and puree into a soup. The cooking and blending break down the fibers enough to be palatable. Or, honestly, compost them and note the lesson for next time.

Post-Harvest Handling

Don’t wash before storing. Moisture promotes rot. Brush off loose soil and store dry.

Remove leaves immediately. The leaves continue drawing moisture from the bulb after harvest. Cut them off at the stem to extend storage life.

Short-term storage: Whole, unpeeled kohlrabi keeps in the refrigerator crisper drawer for 2-3 weeks. Wrap in a damp paper towel inside a perforated plastic bag.

Long-term storage: For large harvests, kohlrabi stores well in a root cellar or cold storage at 32-40°F (0-4°C) with high humidity. Under these conditions, it can last 2-3 months.

Freezing: For even longer preservation, peel, dice, blanch for 2 minutes, ice-bath, and freeze. Frozen kohlrabi keeps 10-12 months. See our freezing guide for detailed instructions.

Harvesting for Container-Grown Kohlrabi

If you’re growing kohlrabi in containers, the timing and method are the same as in-ground plants. The main difference is that container-grown kohlrabi may mature slightly faster (containers warm up quicker in spring) or slightly slower (if the container dries out frequently and stresses the plant).

Check container kohlrabi daily once the bulb starts swelling. Container plants can go from perfect to overgrown faster than garden plants because the confined root space limits how long the plant can sustain healthy growth.

Quick Reference

Factor	Guideline
Harvest size (standard)	2-3 inches diameter
Harvest size (giant)	4-10 inches diameter
Days from transplant	45-65 (standard), 70-130 (giant)
Days from direct sow	55-75 (standard), 80-140 (giant)
Best time of day	Morning (highest water content)
Tool needed	Sharp knife or garden scissors
Frost tolerance	Light frost OK, harvest before hard freeze

The key takeaway: when in doubt, harvest early rather than late. A slightly undersized kohlrabi is still tender and sweet. A slightly oversized kohlrabi may already be turning woody. You can always let the next one grow a bit bigger — you can’t undo woodiness once it sets in.