AdewebsBack when I first stumbled across kohlrabi in a seed catalogue, it looked so odd I nearly flipped the page. This knobbly little thing with leaves sticking out of it? Not your everyday cabbage or carrot. But something about it caught my eye and I thought, why not give it a try?
But curiosity got the better of me, so I bought a packet of kohlrabi seeds, tilled up a corner of the garden, and had a go. The first harvest shocked me. The bulbs were crisp, sweet, and far easier to grow than I had feared. That was when I realised how underrated this crop is.
Since then, I’ve planted kohlrabi in spring and autumn every year, and I’ve learned a few tricks along the way. The great thing is you don’t need a huge farm or fancy equipment. Even a small backyard plot or raised bed can give you more than enough bulbs to feed a family. Folks in the US and UK sometimes ask me if this plant “sheds” or bolts easily. The truth is, once you understand its growing pattern, you’ll see it’s as steady as a Sunday roast.
So whether you’re an old-school grower or just getting into home gardening, kohlrabi deserves a spot in your rotation. This full guide will walk you through everything — from sowing kohlrabi seeds to harvesting, storage, and even some kitchen tips. And I’ll throw in some personal mishaps and lessons learned because farming isn’t perfect, and that’s half the fun, isn’t it?
Understanding Kohlrabi
Kohlrabi is part of the brassica family, like cabbage and broccoli, but it forms a swollen stem above the ground instead of a head. That’s the bit you eat. When it’s young, it’s crisp like an apple but with a mild cabbage taste. If you’re in a cooler part of the US, the UK, or any other temperate region, this is a plant that won’t mind your weather.
Many folks mistake kohlrabi for a root vegetable, but it’s actually a stem crop. That means it doesn’t like being transplanted roughly. If you treat it kindly, it rewards you with plump bulbs. The leaves are also edible — a fact many people overlook. I often sauté them with garlic and oil just like spinach.
How to Plant and Grow Kohlrabi (Full Guide)
Here is step by step guide on how to grow Kohlrabi;
Choosing and Sowing Kohlrabi Seeds
When you’re buying kohlrabi seeds, go for varieties suited to your season. There are early, mid-season, and storage types. In my experience, the early types are best for beginners because they’re fast and forgiving. Look for names like ‘Kolibri’ or ‘Early White Vienna.’
Direct sowing works well in loose soil. Make shallow rows about half an inch deep and sow seeds thinly. Cover lightly and water gently. If you’re using trays, transplant very carefully at the seedling stage before they get leggy. Kohlrabi hates having its roots disturbed too much.
I’ve made the mistake of overcrowding seedlings and ended up with small, woody bulbs. Don’t be like me. Thin them to about 6 to 8 inches apart. It feels wasteful, but the remaining plants will thrive.
Preparing the Soil
Good soil makes the difference between a decent crop and a bumper harvest. Kohlrabi likes a fertile, well-drained bed with plenty of organic matter. I usually dig in compost or well-rotted manure a few weeks before sowing.
Check your soil’s pH if you can. Brassicas prefer slightly alkaline conditions, around 6.5 to 7.5. If your soil is acidic, add a little lime to raise the pH. This helps prevent clubroot, a nasty disease that can ruin brassicas.
And don’t forget, kohlrabi appreciates steady moisture. If your soil dries out too much, the bulbs can split or turn woody. Mulch around the plants to keep moisture even.
Watering and Feeding
Steady watering is key. I usually give mine a good soak once or twice a week rather than a sprinkle every day. This encourages deep roots and plump bulbs. In dry spells, I’ll check the soil with my finger. If it’s dry an inch down, it’s time to water.
As for feeding, kohlrabi isn’t greedy but it does like a boost. A balanced vegetable fertiliser or a light side-dressing of compost tea every couple of weeks keeps it happy. Don’t overdo nitrogen though. Too much leafy growth can mean small bulbs.
Light and Temperature Needs
Kohlrabi thrives in full sun but will tolerate partial shade, especially in hot summers. In cooler climates like Scotland or the northern US, plant it in the sunniest spot you’ve got.
It’s a cool-weather crop, so sow in early spring for a late spring harvest, or sow in late summer for an autumn crop. I’ve even had luck with winter crops under a simple cloche. Timing is everything. If it gets too hot, the plants can bolt.
Training for Success
You don’t “train” kohlrabi like you would a vine, but you do manage it. Keep the bed weed-free. Weeds compete for nutrients and water and can hide pests. I hoe lightly around the plants once a week.
If you’re short on space, you can interplant kohlrabi with quick greens like lettuce. By the time the kohlrabi bulbs swell, the greens are ready to harvest. It’s a good way to make the most of a small plot.
Pest and Disease Control
Cabbage worms, flea beetles, and aphids are the main troublemakers. I use floating row covers right after sowing to keep the pests off. It’s simple and it works.
Check the undersides of leaves regularly. If you spot holes or green caterpillars, pick them off. A mild soap spray can handle aphids. Rotate your crops each year to keep soil diseases at bay. Never plant kohlrabi in the same spot as last year’s brassicas.
Harvesting at the Right Time
Harvesting at the right stage makes all the difference. The bulbs are best when they’re about the size of a tennis ball. Bigger than that and they can get tough and woody.
Use a sharp knife to cut the stem just above the root. Leave the root in the ground if you like. Sometimes you’ll get a few small shoots sprouting that are still tender. Don’t forget the leaves — they’re nutritious and tasty.
Storing and Using Kohlrabi
Freshly harvested kohlrabi keeps well in the fridge for a week or two. For longer storage, remove the leaves and keep just the bulbs in a cool place. Some varieties store for months if conditions are right.
In the kitchen, kohlrabi is versatile. I eat it raw in salads, roast it with olive oil, or mash it like potatoes. The flavour is mild enough to blend into soups and stews. It’s a good low-carb substitute for root veggies too.
FAQs About Growing Kohlrabi
Does kohlrabi shed or bolt easily?
Not usually, but hot weather or inconsistent watering can trigger bolting. Plant at the right time for your climate to avoid this.
How long does it take to grow from seed to harvest?
Most varieties are ready in 45 to 60 days. Some storage types take a little longer.
Can you eat the leaves?
Yes, they’re perfectly edible and full of vitamins. Treat them like kale or collard greens.
Do you need a lot of space?
Not at all. A small raised bed or even large containers will do. Just keep the plants spaced properly.
What’s the difference between purple and green varieties?
Mostly colour. The taste is similar, but purple types can be a bit sweeter and are more eye-catching.
Tips from the Field
Plant a few seeds every couple of weeks instead of all at once. This way you’ll have a steady supply rather than a glut. Also, don’t be afraid to experiment with companion planting. I’ve found that growing kohlrabi near onions helps deter some pests.
And if you’re nervous about trying it for the first time, start small. A single packet of kohlrabi seeds can give you dozens of bulbs. Once you taste homegrown kohlrabi, you’ll wish you’d planted more.
Wrapping It Up
Growing kohlrabi isn’t complicated, but it rewards attention to detail. Give it good soil, steady water, and a bit of space, and it will surprise you. For farmers and gardeners in the US, UK, and other cooler regions, it’s an easy way to diversify your crops without a lot of fuss.
I hope this guide makes you feel confident enough to give kohlrabi a go. From sowing to harvesting, it’s a satisfying journey that ends with a crisp, sweet bulb on your table.
So what’s stopping you from sowing a few kohlrabi seeds this season and seeing for yourself?
