How to Grow Kohlrabi (Ganth Gobhi) in Pots Before It Goes Woody
Kohlrabi (ganth gobhi) is the quickest cabbage family vegetable you can grow in a pot: sow from October to December on the plains, keep the soil evenly moist, and cut the swollen stems when they are between golf ball and tennis ball size, usually around two months after sowing. That size rule is the whole secret. Leave them to grow bigger and they turn woody, which is why so many home grown ganth gobhi end up in the compost.
Quick facts
- Sow: October to December (plains); September to January (Karachi); September to October and again February (Islamabad, Peshawar); March to May (hills)
- Depth: 1.5 cm
- Spacing: 15 cm (6 inches) between plants
- Pot: at least 12 inches (30 cm) wide and deep; holds three to four plants
- Sun: 5 to 6 hours or more
- Harvest: about 6 weeks for baby bulbs, up to about 12 weeks for full size
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When to sow kohlrabi, city by city
Kohlrabi likes cool weather and steady growth. Heat makes it tough and bitter; a hard freeze on very young plants can make them bolt. The safe windows below dodge both.
| Zone | Sowing range | Why |
|---|---|---|
| Punjab plains: Lahore, Faisalabad, Delhi | Early October to mid December | Stagger sowings every 3 weeks for a steady supply |
| Hot dry: Multan, Bahawalpur, Sukkur | Late October to November | Finish before February warms up |
| Coastal: Karachi | Late September to January | Mild winter gives the longest window |
| Sub-humid: Islamabad, Peshawar | September to October, then February | Avoid sowing in the coldest weeks |
| Hills | March to May | A spring and early summer crop there |
How to grow kohlrabi in pots
- Fill a 30 cm (12 inch) pot or a 20 litre grow bag with 2 parts soil, 1 part compost and 1 part cocopeat or sand. See our potting mix guide.
- Sow seeds thinly, 1.5 cm deep, or two seeds per small cup if you want to transplant.
- Keep moist. Seedlings usually appear in about a week in mild weather.
- Thin to one plant every 15 cm. Thinning feels wasteful, but crowded kohlrabi never swells properly. Eat the thinnings as micro greens.
- If raising in cups, transplant at four true leaves, setting them at the same depth; buried stems make lopsided bulbs.
- Mix compost in at sowing and give a nitrogen rich liquid feed every two to three weeks while leaves are growing.
The full tray method is in seed starting at home.
Watering: the hidden cause of woody bulbs
Dry soil, even for a few days, is the second reason kohlrabi turns fibrous, after leaving it too long. The RHS links woodiness directly to dry soil and recommends mulching.
- October to November: every 2 to 3 days in pots.
- December to January (fog and frost): every 4 to 5 days, in the morning, at the soil.
- February: back to every 2 days as days warm.
- A thin layer of dry leaves or straw on top of the pot halves the drying.
Kohlrabi leaves turning yellow or full of holes?
| What you see | Likely cause | First response |
|---|---|---|
| Holes, green caterpillars, droppings | Cabbage caterpillars | Hand pick every evening; check under leaves for eggs; fine mesh over pots |
| Grey clusters under leaves | Cabbage aphid | Wash off with water; soap spray per label if heavy |
| Tiny shot holes on seedlings | Flea beetle | Usually outgrown; cover young seedlings with mesh |
| Lower leaves yellow, rest fine | Normal ageing | Remove them |
| All leaves pale yellow | Hungry plant | Liquid nitrogen feed, compost top up |
The harvest rule: cut at golf ball to tennis ball size
Measure with your fingers: when the bulb is roughly 5 to 7 cm across, cut it at soil level. Bigger is not better. The RHS warns bulbs left too long lose flavour and turn woody, especially in hot, dry weather. Sow a few seeds every three weeks rather than a whole packet at once, so you always have bulbs at the right size instead of twenty going woody together.
Harvesting and using the whole plant
Cut the bulb just above the soil and trim the stalks off. Young leaves are edible: cook them like saag. The bulb keeps for a week or two in the fridge with the leaves removed. Peeling, choosing and cooking are covered in our ganth gobi picking and cooking guide.
Green and purple types grow the same way. Purple ones are said to stand cold a little better, but both are white inside.
Grow it or skip it?
Grow it. Kohlrabi is fast, fits in a 12 inch pot, and gives a clear harvest signal, which makes it a good first brassica after easier crops in our first five plants list. Skip it only if you cannot water regularly; it punishes dry spells more than most. More winter crops sit in Kitchen Garden.
Caterpillars tempt people to reach for strong sprays, but you eat this plant within weeks. Hand picking and mesh first. If you use any product, read the label for the waiting time before harvest, wear gloves, and keep children and pets away until it dries. Wash all harvested bulbs and leaves well.
Kohlrabi growing questions
How do you grow kohlrabi at home?
Sow seeds 1.5 cm deep in a sunny pot or bed between October and December, thin to 15 cm apart, keep the soil evenly moist and harvest at golf to tennis ball size.
Can kohlrabi grow in pots?
Yes. A pot at least 30 cm wide and deep holds three or four plants.
When should kohlrabi be sown in Pakistan?
October to mid December on the Punjab plains, later into January in Karachi, and September to October in Islamabad.
How many days does kohlrabi take to grow?
Baby bulbs in about six weeks; full size in roughly two to three months, depending on variety and cold.
How long do kohlrabi seeds take to germinate?
Usually about a week in mild weather, longer in cold soil.
When should I harvest kohlrabi?
When the bulb is 5 to 7 cm across. Larger bulbs tend to be woody.
Why is my kohlrabi not forming a bulb?
Crowding, heat or a dry pot are the usual reasons. Thin to 15 cm apart and keep the soil steadily moist.
Why is my kohlrabi woody?
It was left too long or went dry. Pick younger and mulch the pot.
Ganth gobhi kaise ugaye?
October se December tak beej 1.5 cm gehre gamle mein boyein, paude 15 cm door rakhein, mitti nam rakhein, aur gend jitna hone par kaat lein.