GrowSabzHow to grow corn in pots
Also called Maize, Sweet Corn, makai, bhutta · Zea mays
مکئی
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 4.5 Levery 2 days, 30 L pot
- 🌡️ Ideal temp
- 21–32°C
- 🪴 Min pot
- 30 L40 cm deep
- 🧺 Harvest
- 60–100days from sowing
- ⚖️ Yield
- 2 kgper 20 L pot
Corn drinks far more than most container plants — about 1000 ml for every 10 litres of soil, and in hot weather it wants that every single day. Underestimate that and you get the classic result: a plant that looks healthy in the morning and wilts by afternoon.
Short answer
Grow corn in a 30 litre container at least 40 cm deep, watering about 1000 ml per 10 litres of soil every 2 days, and keep temperatures between 21 and 32 °C. First harvest comes 60–100 days after sowing.
Where to plant it
What size pot does corn need?
30 litres and 40 cm deep is the realistic minimum for a single plant. Pick a container below to see what changes.
| Container | Minimum size | Depth | Notes |
|---|---|---|---|
| Pot | 30 L | 40 cm | Requires large pots and consistent watering. Best for dwarf varieties. |
| Grow bag | 30 L | 40 cm | Fabric bags provide good aeration but dry out faster. |
| Open ground | — | 60 cm | Plant in blocks for better wind pollination. Requires fertile, well-drained soil. |
| Raised bed | 40 L | 50 cm | Excellent for deep root development and soil control. Ensure adequate spacing. |
Watering
How often should you water corn?
Every 2 days through the growing season, at about 1000 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 deep root watering works best.
Too little water
- leaf curling
- wilting
- poor kernel development
Too much water
- yellowing leaves
- stunted growth
- root rot
Avoid: shallow watering; waterlogging; overhead watering during tasseling.
Climate
Can you grow corn where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 21 – 32 °C |
|---|---|
| Survives | 5 – 38 °C |
| Germinates above | 10 °C — best at 24 °C, about 7 days |
| Flowers drop | above 35 °C, or below 10 °C |
| Sunlight | 6–12 hrs/day, best 8 |
| Frost | Highly sensitive — will not survive it |
The flower-drop thresholds matter more than the survival ones. A plant can be perfectly alive at 38 °C and still give you nothing.
How cold is too cold for corn? Check your temperaturesEnter your night low and day high — see if it survives, and if it will cropTimeline
Corn 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 corn
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 corn fails, and how to avoid it
- A container that is too small
Below 30 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. Corn wants about 1000 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Ignoring the flower-drop threshold
Above 35 °C, or below 10 °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 Tomato
Both corn and tomatoes are susceptible to corn earworm (also known as tomato fruitworm), which can devastate both crops.
- Leaving it out through a cold snap
Corn is highly frost-sensitive. One night below 5 °C can end the plant outright — bring containers in or cover them.
Companions
What to plant with corn
Good neighbours
Beans are nitrogen fixers, enriching the soil for corn. Pole beans can also use corn stalks for support.
Squash plants act as a living mulch, shading the soil, suppressing weeds, and retaining moisture. Part of the 'Three Sisters' planting method.
Similar to squash, pumpkins provide ground cover, suppress weeds, and help retain soil moisture, benefiting corn.
Repels nematodes and other harmful soil pests that can affect corn roots.
Attracts beneficial pollinators and predatory insects, which can help control corn earworms and other pests.
Keep apart from
Both corn and tomatoes are susceptible to corn earworm (also known as tomato fruitworm), which can devastate both crops.
Members of the Brassica family (cabbage, broccoli, kale) are heavy feeders and compete with corn for nutrients, potentially stunting corn growth.
Fennel produces substances that can inhibit the growth of many plants, including corn.
Sunflowers are tall and aggressive growers that compete with corn for sunlight, water, and nutrients, often to the detriment of corn.
Problems
Corn 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.
Corn Earworm humidity any · temp >20
Larvae feed on corn silks and developing kernels inside the ear, causing significant damage and opening pathways for fungal infections.
European Corn Borer humidity any · temp >15
Larvae bore into stalks, tassels, and ears, weakening the plant, causing stalk breakage, and direct damage to kernels.
Corn Smut humidity any · temp 18-27
Fungal disease causing large, silvery-white galls on ears, tassels, stalks, and leaves. Galls eventually rupture, releasing black spores.
Rust humidity >90% · temp 18-25
Appears as small, raised, reddish-brown pustules on leaves, which can merge and cause premature leaf death, reducing yield.
Aphids humidity any · temp 15-25
Cluster on new growth and undersides of leaves, sucking sap, causing stunted growth, distorted leaves, and secreting sticky honeydew.
Stalk Rot humidity >80% · temp 20-30
Fungal disease causing internal decay of the stalk, leading to premature plant death and lodging (falling over) before harvest.
Stewarts Wilt humidity any · temp >20
Bacterial disease spread by flea beetles. Causes long, irregular streaks on leaves, wilting, and premature death, especially in sweet corn.
Northern Corn Leaf Blight humidity >90% · temp 18-27
Fungal disease characterized by large, cigar-shaped, grayish-green lesions on leaves, leading to reduced photosynthesis and yield.
Drought Stress humidity <40% · temp >30
Corn is highly sensitive to water stress during pollination and kernel filling, leading to poor ear development and reduced yield. Leaves may roll to conserve moisture.
Nitrogen Deficiency humidity any · temp any
Causes yellowing of older leaves, starting from the tip and moving down the midrib in a 'V' shape. Overall stunted growth.
Harvest
When to harvest corn
First picking falls between day 60 and day 100.
How to tell it's ready
- Silks are dry and brown
- Kernels are plump and release milky liquid when punctured
- Ear feels firm and full
How much to expect
Storing it: Refrigerate immediately (unhusked) for up to 1 week, or blanch and freeze for longer storage.
Questions
Corn: common questions
How long does corn take to grow?
About 80 days from sowing to the first harvest, with picking usually starting between day 60 and day 100. Warm weather pulls that forward; cool weather pushes it back.
What size pot does corn need?
At least 30 litres and 40 cm deep for one plant. A raised bed wants 40 litres of soil and 50 cm of depth.
How often should I water corn?
About 1000 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 corn need?
It does best between 21 °C and 32 °C and survives from 5 °C to 38 °C. Seed needs soil above 10 °C to germinate, ideally around 24 °C.
Can I grow corn in winter?
Not outdoors anywhere that frosts — it is highly frost-sensitive and will not survive it. In a frost-free winter it grows slowly; anywhere colder, treat it as a warm-season crop.
How do I know when corn is ready to harvest?
Silks are dry and brown; Kernels are plump and release milky liquid when punctured; Ear feels firm and full. Once picked: refrigerate immediately (unhusked) for up to 1 week, or blanch and freeze for longer storage.
How much does one corn plant produce?
Roughly 2 kg from a 20 litre container, or about 10 kg in open ground. Larger containers give proportionally more, up to a point.