GrowSabzHow to grow kohlrabi in pots
Also called German Turnip, Stem Turnip, kohl rabi, gobi shalgam · Brassica oleracea var. gongylodes
گوبھی شلجم
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 0.8 Levery 2 days, 10 L pot
- 🌡️ Ideal temp
- 13–24°C
- 🪴 Min pot
- 10 L20 cm deep
- 🧺 Harvest
- 50–70days from sowing
- ⚖️ Yield
- 1.5 kgper 20 L pot
Kohlrabi grows well in containers given the right depth, consistent water and enough sun. From sowing to harvest takes about 55 days. The sections below cover the whole cycle — container size, exact watering amounts, feeding, what to watch for, and when to pick.
Short answer
Grow kohlrabi in a 10 litre container at least 20 cm deep, watering about 700 ml per 10 litres of soil every 2 days, and keep temperatures between 13 and 24 °C. First harvest comes 50–70 days after sowing.
Where to plant it
What size pot does kohlrabi need?
10 litres and 20 cm deep is the realistic minimum for a single plant. Pick a container below to see what changes.
| Container | Minimum size | Depth | Notes |
|---|---|---|---|
| Pot | 10 L | 20 cm | Ensure good drainage |
| Grow bag | 10 L | 20 cm | Fabric bags promote air pruning |
| Open ground | — | 25 cm | Space plants adequately |
| Raised bed | 20 L | 25 cm | Excellent for drainage and soil control |
Watering
How often should you water kohlrabi?
Every 2 days through the growing season, at about 700 ml per 10 litres of soil — daily in hot weather, every 3 days when it turns cool. Water in the early morning. Drip irrigation or base watering works best.
Too little water
- stunted growth
- woody bulbs
- cracking bulbs
Too much water
- yellowing leaves
- soft stem
- root rot
Avoid: water on leaves; standing water; inconsistent watering.
Climate
Can you grow kohlrabi where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 13 – 24 °C |
|---|---|
| Survives | -4 – 30 °C |
| Germinates above | 7 °C — best at 18 °C, about 7 days |
| Flowers drop | above 28 °C, or below -2 °C |
| Sunlight | 6–10 hrs/day, best 8 |
| Frost | Medium sensitivity |
The flower-drop thresholds matter more than the survival ones. A plant can be perfectly alive at 30 °C and still give you nothing.
How cold is too cold for kohlrabi? Check your temperaturesEnter your night low and day high — see if it survives, and if it will cropTimeline
Kohlrabi growing stages, day by day
Click any stage to see what's happening. Durations shift with temperature — a warm season runs roughly a quarter faster than a cool one.
Feeding
Fertiliser schedule for kohlrabi
Feed on the interval below, changing what you give as the plant shifts from making leaves to making fruit.
| Stage | What to use | Per 10 L | Every |
|---|
How to prepare each feed
Common mistakes
Why kohlrabi fails, and how to avoid it
- A container that is too small
Below 10 litres the root run is too shallow. The plant grows, flowers late, and drops whatever it sets because it cannot support the crop.
- Watering too lightly
A daily splash wets the top few centimetres and nothing else. Kohlrabi wants about 700 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Wetting the leaves
Overhead watering in the evening leaves foliage damp overnight, which is exactly the condition fungal disease needs. Water the soil, early in the day.
- Ignoring the flower-drop threshold
Above 28 °C, or below -2 °C, flowers fall before setting. The plant can look perfectly healthy and still give you nothing — shade it through the hottest hours.
- Planting it beside Strawberry
Can stunt the growth of kohlrabi due to competition for nutrients and space.
Companions
What to plant with kohlrabi
Good neighbours
Deters common brassica pests like cabbage worms and aphids with its strong scent.
Emits a strong scent that deters spider mites, aphids, and cabbage loopers.
Roots produce a chemical that kills root-knot nematodes, and flowers repel other harmful insects.
Fixes nitrogen in the soil, benefiting kohlrabi's growth, and can deter some pests.
Deters flea beetles and cabbage moths. Plant in containers to prevent spreading.
Keep apart from
Can stunt the growth of kohlrabi due to competition for nutrients and space.
Can stunt the growth of kohlrabi and other brassicas.
Competes heavily for light and nutrients, potentially stunting kohlrabi.
Attracts similar pests and diseases, increasing the risk for kohlrabi.
Can inhibit the growth of kohlrabi and other brassicas.
Problems
Kohlrabi pests and diseases
Each lists the weather that brings it on, so you know when to start checking rather than reacting once it's established.
Cabbage Worms Loopers humidity any · temp 18-30
Green caterpillars that chew large, irregular holes in leaves. Can quickly defoliate plants.
Flea Beetles humidity any · temp >15
Small, jumping beetles that chew tiny 'shot-hole' perforations in leaves, especially on young plants.
Aphids humidity any · temp 15-25
Small, soft-bodied insects that cluster on new growth and undersides of leaves, sucking sap and causing distorted growth.
Clubroot humidity soil saturation · temp 18-25
A soil-borne fungal disease that causes swollen, distorted roots, leading to stunted growth and wilting. Prevalent in acidic, wet soils.
Downy Mildew humidity >90% · temp 10-20
Causes yellow patches on the upper leaf surface and a fuzzy, grayish-purple mold on the underside. Leads to leaf decay.
Black Rot humidity >80% · temp 20-30
Bacterial disease causing V-shaped yellow lesions on leaf margins that turn brown/black. Affects vascular tissue.
Bolting humidity any · temp >25 or <10
Premature flowering and seed stalk development, often triggered by sudden temperature changes, prolonged heat, or stress. Makes bulbs woody and bitter.
Harvest
When to harvest kohlrabi
First picking falls between day 50 and day 70.
How to tell it's ready
- Bulb is 2-4 inches (5-10 cm) in diameter
- Bulb feels firm and tender, not woody
How much to expect
Storing it: Store kohlrabi bulbs in the refrigerator for up to 2-3 weeks. Leaves can be stored separately for a few days.
Questions
Kohlrabi: common questions
How long does kohlrabi take to grow?
About 55 days from sowing to the first harvest, with picking usually starting between day 50 and day 70. Warm weather pulls that forward; cool weather pushes it back.
What size pot does kohlrabi need?
At least 10 litres and 20 cm deep for one plant. A raised bed wants 20 litres of soil and 25 cm of depth.
How often should I water kohlrabi?
About 700 ml per 10 litres of soil, every 2 days in normal weather — daily when it is hot and every 3 days when cool. Water in the early morning.
What temperature does kohlrabi need?
It does best between 13 °C and 24 °C and survives from -4 °C to 30 °C. Seed needs soil above 7 °C to germinate, ideally around 18 °C.
Can I grow kohlrabi in winter?
It tolerates cold better than most, down to about -4 °C, so a sheltered spot or a cold frame will often carry it through.
How do I know when kohlrabi is ready to harvest?
Bulb is 2-4 inches (5-10 cm) in diameter; Bulb feels firm and tender, not woody. Once picked: store kohlrabi bulbs in the refrigerator for up to 2-3 weeks. leaves can be stored separately for a few days.
How much does one kohlrabi plant produce?
Roughly 1.5 kg from a 20 litre container, or about 4 kg in open ground. Larger containers give proportionally more, up to a point.