Corn: Sowing, planting and harvest calendar
How do you sow maize outdoors?
To harvest tender, sweet ears, choose a sweetcorn variety suited to your climate. Sow outdoors after the risk of frost has passed, when the soil has warmed to at least 10 °C; seeds may rot in cold, wet soil. Choose a sunny, sheltered spot with fertile, well-drained soil. Sow about 2.5 cm deep, following the spacing on the packet: for many sweetcorn varieties, allow roughly 35–45 cm in both directions.
Sow two or three seeds per position, then keep the strongest seedling. Arrange sweetcorn in a block of several short rows so wind can carry pollen between plants and help kernels develop. Baby corn harvested before pollination can be grown differently; follow the instructions for your variety. Water gently after sowing and keep the soil moist without waterlogging it. Weed carefully while the plants are young, avoiding their shallow roots.
In a cool climate, start under cover in spring: sow one seed per deep pot with drainage holes, about 2.5 cm deep in seed compost. A temperature of 18 to 21 °C encourages germination. Keep the compost slightly moist and provide good light from germination. Gradually harden the plants off, then plant the intact root balls outdoors after the last frosts, before the roots become cramped.
How to care for this plant
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Earth up plants
Once your sweetcorn is established and growing taller, check its stability, especially in a windy spot. If plants need anchoring, draw a little soil around the stem bases without burying the leaves.
When do you harvest maize?
For sweetcorn, check the ears when the silks start turning brown. Peel back a little of the husk and pierce a kernel with your fingernail: a milky liquid indicates that it is ready, a watery liquid that it needs more time, and a thick paste that it is past its best for eating fresh. Harvest time depends on the variety, sowing date and weather. Twist a ripe ear away from the stem while supporting the plant.
Eat sweetcorn soon after picking for the best flavour, or refrigerate it promptly if you need to keep it briefly. To freeze it, use a reliable method with blanching times suited to whole ears or kernels, then cool and drain it before packing; a year of storage does not apply to fresh ears. For popcorn, choose a suitable variety and allow the kernels to dry fully. Grain maize is harvested at a different stage from sweetcorn, while baby corn is picked young, before pollination.
Corn
- Type : Vegetables
- Subtype : Fruiting vegetables
- Botanical Family : Poaceae (grasses)
Characteristics
- Lifecycle : Annual
- Exposure : Full Sun
- Frost Hardiness : Frost Sensitive
- Cultivation Difficulty : Easy
- Mature height : 250 cm
Sowing & Planting
- Greenhouse Growing : Not Required
- Sowing Depth : 2 cm
- Plant Spacing : 15 cm
- Row Spacing : 50 cm
Maintenance
- Maintenance : Moderate
- Water Requirements : High
Other characteristics
- Soil Type : Humus-rich
- Soil pH Preference : Neutral
- Pest Sensitivity : Moderate
- Disease Sensitivity : Moderate
- Weed Sensitivity : High
- Pollination : Wind-pollinated
- Propagation : Sowing