Corn (Zea mays) - How to Grow & Care Guide

Plant Snapshot

Common Name: Corn
Latin Name: Zea mays
Alternate Names: Maize, Sweet corn, Field corn
Hardiness Zones: Annual crop not winter hardy. Grow where there is a frost free growing season.
Typical Height: 5–10 ft (150–300 cm) depending on variety and growing conditions
Typical Spread: Footprint depends on planting arrangement commonly 8–36 in (20–90 cm) from single plant spacing to row spacing
Bloom Period: Tasseling and silking occur in summer several weeks after sowing; exact timing depends on planting date and climate
Soil Preferences: Fertile, well drained loam to sandy loam with consistent moisture. Ideal pH about 6.0 to 6.8. Poor drainage reduces growth and yield
Light Preferences: Full sun. Provide at least 6 to 8 hours of direct sun daily for best yield
Toxicity: Not toxic to humans or common pets according to pet poison authorities. Whole cobs and many whole kernels can be a choking or obstruction risk for pets. Corn pollen may trigger allergies in people
Propagation: Propagate by seed. Direct sow after soil warms. Plant in blocks for pollination. Transplanting is possible but can reduce yield due to root disturbance

Key Facts

Warm season annual cereal grass
Grown for fresh sweet corn and for grain or silage
Wind pollinated with separate male tassels and female silks
Direct sown after soil warms to at least about 50 to 60°F (10 to 16°C)
Prefers fertile, moist, well drained soil
Requires full sun for best yield
Very sensitive to frost
Plant in blocks rather than single long rows to improve pollination
Needs steady moisture during tassel and silk development for good ear fill

Corn (Zea mays) is a warm season annual cereal grown for fresh sweet corn, grain and silage. It performs best in full sun on fertile, well drained soil and will not tolerate frost. Sow seed after soil has warmed to about 50 to 60°F and arrange plants in blocks to encourage good pollination and ear fill.

Identification

Corn is a tall grassy annual that commonly reaches about 5 to 10 feet depending on variety and growing conditions. Plants produce separate male tassels at the top and female silks on developing ears, and pollination is by wind rather than insects. Corn plants die with the first hard frost and are not winter hardy.

Best uses and where to grow

Grow corn for fresh eating, roasting, freezing or for grain and silage when space and a long frost free season allow. It needs at least 6 to 8 hours of direct sun and fertile, well drained loam to sandy loam. Corn is not suited to small containers and benefits from garden locations with steady moisture and easy access for harvesting.

When to plant

Direct sow after the soil warms to roughly 50 to 60°F and after the last spring frost in your area. Corn is very sensitive to frost so timing should match your local frost free season. For a continuous summer harvest, stagger plantings several weeks apart but adjust to your local growing season and expected tassel and silk timing.

Planting and spacing

Seed corn directly into the garden and space plants about 8 to 12 inches apart in the row with rows commonly 30 to 36 inches apart. Plant in short adjacent rows or blocks rather than a single long row to improve wind pollination and increase the chance of fully filled ears. Transplants can be used but may reduce yield from root disturbance.

Watering and soil

Corn prefers fertile soil with consistent moisture and a pH around 6.0 to 6.8. Steady watering is critical during tassel and silk development because drought at that stage commonly causes poor ear fill. Avoid waterlogged soils; good drainage and regular moisture produce the best yields.

Pollination and improving ear set

Because corn is wind pollinated, plant layout and timing determine ear set more than insect activity. Arrange plants in blocks so tassels and silks are close together and stagger planting dates carefully to align pollination. Poor pollination shows as missing kernels along the ear and often results from sparse planting or weather that inhibits pollen movement.

Harvest and after flowering care

Harvest sweet corn when ears reach desired tenderness and kernels are milky; timing varies by variety. For grain harvest wait until kernels mature and dry on the stalk. After harvest remove or chop down stalks to reduce volunteer seedlings and to prepare beds for next crops. Corn will not survive winter frost so plan crop rotation accordingly.

Controlling spread and volunteers

Corn is an annual and will not persist through winter, but volunteer seedlings can appear from dropped seed. Remove cobs and any seed heads you do not want to reseed. Manage volunteers before they set seed and rotate planting locations to limit pest and disease buildup in the soil.

Frequently asked questions

How fast does corn grow?: Corn typically develops tassels and silks several weeks after sowing and reaches its mature height within the season. Exact speed varies with variety, temperature and soil fertility but plants generally reach 5 to 10 feet before harvest.
When should I plant corn?: Sow seed after soil temperatures reach about 50 to 60°F and after the danger of frost has passed. Timing depends on your local last frost date and the length of your frost free season.
How close should I plant corn?: Space plants about 8 to 12 inches apart in the row with rows typically 30 to 36 inches apart. Planting in blocks rather than single long rows improves wind pollination and ear fill.
Is corn toxic to pets?: Corn is not considered toxic to common pets but whole cobs and large amounts of whole kernels can cause choking or intestinal obstruction. Corn pollen can trigger allergies in some people.
Can I transplant corn?: Transplanting is possible but not usually recommended because root disturbance can reduce yield. If you transplant use large containers and minimize root disruption, and be prepared for potentially lower ear production.