GrowSabzHow to grow kale in pots
Also called Borecole, kail, borecole, leafy green · Brassica oleracea var. sabellica
کیل
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 0.7 Levery 3 days, 10 L pot
- 🌡️ Ideal temp
- 10–24°C
- 🪴 Min pot
- 10 L25 cm deep
- 🧺 Harvest
- 50–75days from sowing
- ⚖️ Yield
- 1.5 kgper 20 L pot
Kale keeps producing once it starts. First picking comes around day 50, and the plant then crops for roughly 90 more days — but only if you keep picking. Letting it run to flower is what ends the supply.
Short answer
Grow kale in a 10 litre container at least 25 cm deep, watering about 600 ml per 10 litres of soil every 3 days, and keep temperatures between 10 and 24 °C. First harvest comes 50–75 days after sowing.
Where to plant it
What size pot does kale need?
10 litres and 25 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 | 25 cm | Ensure good drainage to prevent root rot. |
| Grow bag | 10 L | 25 cm | Fabric bags provide excellent aeration for roots. |
| Open ground | — | 30 cm | Space plants adequately for air circulation and growth. |
| Raised bed | 20 L | 30 cm | Ideal for controlling soil quality and drainage. |
Watering
How often should you water kale?
Every 3 days through the growing season, at about 600 ml per 10 litres of soil — every 2 days in hot weather, every 4 days when it turns cool. Water in the early morning. Drip irrigation or base watering works best.
Too little water
- wilting leaves
- stunted growth
- bitter taste
Too much water
- yellowing lower leaves
- stunted growth
- root rot
Avoid: overhead watering in humid conditions; soggy soil.
Climate
Can you grow kale where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 10 – 24 °C |
|---|---|
| Survives | -10 – 30 °C |
| Germinates above | 7 °C — best at 21 °C, about 7 days |
| Flowers drop | above 28 °C, or below -5 °C |
| Sunlight | 6–10 hrs/day, best 8 |
| Frost | Low 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 kale? Check your temperaturesEnter your night low and day high — see if it survives, and if it will cropTimeline
Kale 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 kale
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 kale 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. Kale wants about 600 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Ignoring the flower-drop threshold
Above 28 °C, or below -5 °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 Other Brassicas
Other brassicas (cabbage, broccoli, kohlrabi) compete for nutrients and share common pests and diseases, increasing risk.
Companions
What to plant with kale
Good neighbours
Deters cabbage moths and other brassica pests with its strong aroma.
Repels flea beetles and cabbage worms. Plant in containers to prevent spreading.
Attracts beneficial insects like parasitic wasps and ladybugs, which prey on aphids and cabbage worms.
Repels nematodes and other harmful soil pests, improving overall plant health.
Acts as a trap crop for aphids, drawing them away from kale plants.
Deters common kale pests like aphids and slugs with its pungent odor.
Keep apart from
Other brassicas (cabbage, broccoli, kohlrabi) compete for nutrients and share common pests and diseases, increasing risk.
Can stunt the growth of kale and other brassicas.
Some beans can inhibit the growth of kale, possibly due to nitrogen fixation or allelopathic effects.
Grapes can inhibit the growth of kale.
Problems
Kale 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 humidity any · temp 18-29
Green caterpillars (imported cabbageworm, cabbage looper, diamondback moth larvae) chew holes in leaves, often starting from the center. Can quickly defoliate 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 and sticky honeydew.
Flea Beetles humidity any · temp >18
Tiny, jumping beetles that chew small, round holes (shot-holes) in leaves, especially on young plants. Can severely stunt growth.
Slugs Snails humidity >70% · temp 10-20
Leave large, irregular holes in leaves, often with silvery slime trails. Active in damp, cool conditions, especially at night.
Downy Mildew humidity >90% · temp 10-20
Yellowish spots on the upper leaf surface, with fuzzy gray or purplish mold on the underside. Leaves may eventually turn brown and die.
Powdery Mildew humidity 50-70% · temp 20-27
White, powdery patches appear on leaf surfaces, especially in dry, warm conditions with poor air circulation. Can weaken plants.
Black Rot humidity >80% · temp 20-30
V-shaped yellow lesions starting at leaf margins, turning brown/black. Veins within the lesion turn black. Can spread rapidly.
Clubroot humidity any · temp 18-25 · soil_pH <7.0
Causes swollen, distorted roots, leading to stunted growth, wilting, and yellowing leaves. More prevalent in acidic soils.
Alternaria Leaf Spot humidity >80% · temp 20-28
Dark, circular spots with concentric rings (target-like) appear on older leaves. Can cause defoliation and reduced yield.
Bolting humidity any · temp >27
Premature flowering and seed stalk development, often triggered by heat stress or long daylight hours. Leaves become bitter and tough.
Harvest
When to harvest kale
First picking falls between day 50 and day 75, and the plant then keeps producing for about 90 days. Pick often — what you leave on the plant signals it to stop making more.
How to tell it's ready
- Leaves are 8-10 inches long, vibrant green, and tender.
- Outer leaves are mature, but inner leaves are still developing.
How much to expect
Storing it: Wash, dry thoroughly, and store in an airtight bag in the refrigerator for up to 1 week.
Questions
Kale: common questions
How long does kale take to grow?
About 60 days from sowing to the first harvest, with picking usually starting between day 50 and day 75. It then keeps producing for roughly 90 more days. Warm weather pulls that forward; cool weather pushes it back.
What size pot does kale need?
At least 10 litres and 25 cm deep for one plant. A raised bed wants 20 litres of soil and 30 cm of depth.
How often should I water kale?
About 600 ml per 10 litres of soil, every 3 days in normal weather — every 2 days when it is hot and every 4 days when cool. Water in the early morning.
Why is my kale flowering but not fruiting?
Almost always pollination. Kale carries separate male and female flowers and needs pollen moved between them — without insects, nothing sets. Hand-pollinate in the morning with a male flower brushed against the centre of a female one.
What temperature does kale need?
It does best between 10 °C and 24 °C and survives from -10 °C to 30 °C. Seed needs soil above 7 °C to germinate, ideally around 21 °C.
Can I grow kale in winter?
It tolerates cold better than most, down to about -10 °C, so a sheltered spot or a cold frame will often carry it through.
How do I know when kale is ready to harvest?
Leaves are 8-10 inches long, vibrant green, and tender.; Outer leaves are mature, but inner leaves are still developing.. Once picked: wash, dry thoroughly, and store in an airtight bag in the refrigerator for up to 1 week.