
Sweet corn
Sweet corn: plant 25 cm (10 in) apart in the row and 75 cm (30 in) between rows, 1 per square. Good neighbours: Cucumber, Pole beans, Pumpkin.
Key facts
| Spacing in the row | 25 cm (10 in) |
|---|---|
| Between rows | 75 cm (30 in) |
| In a 30 cm (1 ft) square | 1 per square |
| Sun | Full sun, 6–8 hours a day |
| Root depth | 40 cm (16 in) |
| Height when grown | 200 cm (79 in) |
| Crop rotation group | Anywhere in the rotation |
| Support | None needed |
Sowing and germination
| How it is started | Sown straight into the bed |
|---|---|
| Seeds per hole | 2 |
| Plants kept after thinning | 1 |
| Seeds per metre of row | 8 |
| Sowing depth | 2.5 cm (1 in) |
| Soil temperature | from 10 °C, best 18–35 °C |
| Days to emerge | 4–12 days |
| Light while germinating | Light makes no difference |
| Before sowing | nothing needed |
| When to sow | Outdoors after the last frost; soil at least 16 °C |
From seedling to plant
| Pricking out | sown where it grows |
|---|---|
| Takes transplanting | Badly, sow where it grows |
| Hardening off | 7–10 days |
| Life cycle | Annual |
| Cold tolerance | Tender, hurt by frost |
| Soil | Rich, with compost, free draining, pH 6–7 |
| In a pot | 15 L, 35 cm (13.8 in) |
| Watering | Water when the soil is dry two fingers down; at flowering, while fruit sets |
| Feeding | Hungry; at planting, while growing |
| Support and training | None needed; earth up |
Harvest and planning
| Days to first harvest | 70–95 days, from sowing |
|---|---|
| Ready when | The silks are brown and the kernels milky |
| Harvest window | All at once, 1–2 weeks |
| Sow again every | 14 days |
| Typical yield | 0.3–0.6 kg per plant |
| Botanical family | Poaceae |
| Watch out for | Corn borer, birds |
Good neighbours
Cucumber
Pole beans
Pumpkin◐
Butternut squash◐
Zucchini◐
Potato◐
Bush beans◐
Peas
Broad beans
Chickpeas◐
Soybeans
Runner beans
Lima beans
Lentils◐
Black-eyed peas◐
Snow peas
Peanuts◐
Chayote
Delicata squash◐
Acorn squash◐
◐ good with a condition · Why, with the sources →
Plan Sweet corn in your garden
Open the free planner, drop Sweet corn onto a bed and see how many plants fit.
Start Planning Your GardenSowing and harvest
| Sow outdoors | May–Jun |
|---|---|
| Harvest | Aug–Sep |
My dates for this crop
Give the date once and this page, the sowing calendar and the planner all follow it.
- Not recommended
- Marginal
- Conditional
- Favourable
Months for a temperate climate: about a month later in the north and a month earlier in the south. Give your own last frost date for exact dates.
From the same family
Plants of the Poaceae family share diseases and pests, so they follow each other in the rotation only after a break.
Grown much the same way
Crops that need about the same room and care, from another family.
Sources
The values on this page marked as checked come from these sources: spacing, sowing depth, germination, soil, timing and safety notes, each against the source named here.
- Sweet Corn in the Garden — Utah State University Extension for: sowing depth, when to sow, between rows, spacing in the row; checked 2026-10-31
- Illinois vegetable planting dates, spacing and seeds (2020) — University of Illinois Extension for: sowing depth, spacing in the row; checked 2026-10-31
- Seed germination: temperature and timing (Harrington tables) — UC Master Gardener Program, UC ANR for: days to emerge, soil temperature; checked 2026-10-31