edenhana

Sweetcorn

Best planted in blocks rather than a single row so the wind can pollinate it properly; a classic Kiwi summer crop.

Sun
full sun
Water
moderate
Spacing
30cm
Harvest
Ready in 70-90 days
Difficulty
intermediate
Grows in
Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman, Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago, Invercargill / Southland
Expected yield
1-2 cobs per plant
Cost to grow
~$10 NZD
Grocery value
~$35 NZD
Companion plants
Beans, Celery, Cucumbers, Melons, Peas, Radishes, Potatoes
Plants to avoid nearby
Tomatoes
Common diseases
Rust
Common pests
Guava moth caterpillar, Aphids

When to plant by region

In Whangārei / Northland, Auckland, Tauranga / Bay of Plenty, Gisborne and Napier / Hawke's Bay: September-December. In Hamilton / Waikato, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman, Blenheim / Marlborough, West Coast and Christchurch / Canterbury: October-November. In Dunedin / Otago and Invercargill / Southland: November.

Growing stages

  1. Germination & sowing

    • Needs warm soil to germinate; direct sow after frost risk passes
    • Sow in blocks rather than a single row so wind can pollinate properly later on
    • Birds can dig up newly sown seed

  2. Seedling & establishment

    • Aphids can target young seedlings
    • Keep the block planting pattern intact as seedlings establish, rather than gap-filling with single rows
    • Water regularly while roots establish

  3. Vegetative growth

    • Rust can appear on leaves in humid weather
    • Aphids build up on stems and leaves
    • Full sun and moderate water needed for strong stalk growth

  4. Flowering & fruiting

    • Poor pollination and patchy cobs if plants are too spread out or grown in a single row
    • Guava moth caterpillar can get into developing cobs
    • Rust may worsen on foliage as cobs fill out

  5. Harvest70-90 days from sowing

    • Ready from about 70-90 days; expect 1-2 cobs per plant
    • Check for guava moth caterpillar damage at the cob tip before picking
    • Silks turning brown and drying back are a sign cobs are ready

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