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You know kohlrabi is ready to pick when the bulb at the base of the stem reaches about the size of a tennis ball or a golf ball, roughly 2 to 3 inches in diameter.
If you’ve been growing this quirky vegetable and wondering exactly when to harvest it, the size of that swollen stem is your best clue for when kohlrabi is ready to pick.
Picking it at the right moment matters because kohlrabi that stays in the ground too long turns woody and tough, losing that crisp, sweet, apple-like crunch you’re after.
In this post, we’ll dig into the signs that tell you when kohlrabi is ready to pick, what happens if you wait too long, and a few tips to get the perfect harvest every time.
Let’s explore the best ways to know your kohlrabi is ready to pick.
How Do You Know When Kohlrabi Is Ready to Pick by Size
The most reliable way to know when kohlrabi is ready to pick is to measure the bulb, and size is the number one indicator gardeners use.
1. Aim for a 2 to 3 Inch Bulb for the Sweetest Flavor
When kohlrabi is ready to pick, the bulb should feel firm and look plump, and the sweet spot for most varieties is between 2 and 3 inches across.
At this size, the flesh inside is tender, juicy, and mild, which makes it perfect for eating raw in salads or slicing into slaws.
If you harvest when kohlrabi is ready to pick at this smaller size, you’ll get that delicate crunch without any hint of bitterness.
Many gardeners prefer to pick even a bit earlier, around 1.5 to 2 inches, especially for the larger varieties like Superschmelz that can get tough faster.
2. Check the Base of the Bulb for Early Signs
Another trick to know when kohlrabi is ready to pick is to gently brush away a little soil at the base of the bulb.
If you see the bulb starting to swell noticeably above the soil line, that’s a clear signal that growth is happening and harvest time is near.
The bulb should feel solid and dense when you give it a light squeeze, and that firmness tells you the kohlrabi is ready to pick now, not later.
3. Don’t Judge Readiness by Leaf Size Alone
The leaves can be misleading because they grow large and lush even when the bulb is still small, so leaf size alone won’t tell you when kohlrabi is ready to pick.
Instead, focus your attention on the bulb itself, since that’s the part you’ll actually eat and where all the flavor develops.
You’ll know when kohlrabi is ready to pick by looking at the stem’s thickness, not the foliage above it.
Signs Your Kohlrabi Is Past Its Prime
Knowing when kohlrabi is ready to pick also means recognizing what happens if you leave it in the ground too long, and there are a few telltale signs of over-maturity.
1. The Bulb Gets Woody and Tough
If the bulb grows larger than 4 inches, you’ll start to notice the texture changing, and that’s when kohlrabi is no longer ready to pick for best quality.
The outer layer becomes fibrous and woody, and even peeling it deeply won’t save the inner flesh from being chewy and unpleasant.
Once you see cracks on the surface or feel that hard, dense weight, you’ve missed the window for when kohlrabi is ready to pick.
2. Leaves Start Yellowing or Bolting
When the plant begins to bolt, meaning it sends up a flower stalk, the bulb’s energy shifts away from flavor and into seed production.
If you notice the leaves turning yellow or a flower spike forming, your kohlrabi is past the point of being ready to pick for eating.
At this stage, the bulb will taste bitter and the texture will be spongy, so it’s better to pull it and compost it.
3. The Skin Looks Dull or Wrinkled
Fresh kohlrabi that is ready to pick will have a smooth, slightly shiny skin, and if it starts to look dull or wrinkled, that’s an age indicator.
Wrinkling suggests the bulb is drying out internally, and even if it’s not woody, the flavor will be lackluster and mealy.
Check your plants every few days because kohlrabi can go from perfectly ready to pick to overripe faster than you’d expect.
Time and Weather Factors for Knowing When Kohlrabi Is Ready to Pick
Beyond size, the calendar and your local climate can help you predict when kohlrabi is ready to pick, so it’s smart to track days since planting.
1. Count Days to Maturity for Your Variety
Most kohlrabi varieties mature in about 45 to 60 days from seeding, and that range gives you a solid timeline for when kohlrabi is ready to pick.
Check your seed packet for the exact “days to maturity” number, then start checking bulb size around that date to confirm readiness.
Fast-maturing types like Early White Vienna can be ready in as little as 40 days, while storage types might need closer to 60 or 70 days.
2. Cool Weather Slows Growth, Warm Weather Speeds It Up
Kohlrabi thrives in cool conditions, and when temperatures stay between 60 and 70 degrees, the bulbs develop slowly and evenly, giving you a longer harvest window.
If a heatwave hits, the plant may bolt quickly, and that can shorten the time you have to know when kohlrabi is ready to pick.
In warm weather, check bulbs daily because they can jump from small to oversized in just a few hot afternoons.
3. Succession Planting Extends Your Harvest Period
Instead of planting all your kohlrabi at once, sow a new batch every two weeks, and you’ll have a steady supply of bulbs that are ready to pick over several weeks.
This strategy means you won’t be stuck with a giant pile of overripe kohlrabi all at the same time, and you’ll always have some at that perfect 2-inch stage.
Each planting will give you clear signals for when that specific kohlrabi is ready to pick based on its own growth rate.
Testing Firmness and Harvesting Techniques
A hands-on approach is the final way to confirm when kohlrabi is ready to pick, and a simple squeeze test works wonders.
1. Gently Squeeze the Bulb to Feel for Density
When you press lightly on the bulb, it should feel as firm as an apple and give no soft spots, which is the surest sign that kohlrabi is ready to pick.
If it feels spongy or gives under pressure, it’s either too young or starting to deteriorate, so wait another few days or harvest immediately.
2. Cut the Stem, Don’t Pull the Whole Plant
To harvest, use a sharp knife to cut the stem about an inch below the bulb, leaving the roots in the ground if you plan to grow another crop there.
You can also trim the leaves down to about an inch above the bulb, as long as you don’t cut into the edible part itself.
Store your harvested kohlrabi in the fridge, and it will keep for several weeks if you remove the leaves first, since leaves draw moisture away from the bulb.
3. Taste Test a Small Slice for Confirmation
If you’re still unsure when kohlrabi is ready to pick, slice off a thin piece from the bulb’s shoulder and taste it raw.
A sweet, crisp, and slightly peppery bite means it’s perfectly ready to pick, while a bitter or woody flavor tells you it’s past its prime.
This is a fun way to check, and it also gives you a little snack right there in the garden.
So, How Do You Know When Kohlrabi Is Ready to Pick?
You know kohlrabi is ready to pick when the bulb reaches 2 to 3 inches in diameter, feels firm to the touch, and hasn’t started bolting or cracking.
The time-based estimate of 45 to 60 days from seeding is a helpful guide, but bulb size and texture are the true tests.
Keep an eye on those leaves for yellowing, check under the soil for swelling, and do a quick taste test if you’re ever in doubt.
Now that you know how to tell when kohlrabi is ready to pick, you can enjoy that crispy, homegrown goodness at its absolute peak.