Sweetcorn is the classic centrepiece of the Three Sisters, the Native American planting that pairs three crops which each help the others: corn for the beans to climb, beans to fix nitrogen for the hungry corn, and squash to sprawl across the ground, shading out weeds and keeping moisture in. Grown together they make wonderful use of a single patch.
The one thing to know before anything else: sweetcorn is wind-pollinated, so it must be grown in a block, not a long single row. Pollen falls from the tassels at the top onto the silks of the cobs below, and a square block lets the wind do that job evenly — a thin row gives gappy, half-filled cobs no matter how good your companions are.
Grow these alongside
Scramble up the sturdy stems for support and fix nitrogen the hungry corn feeds on — sister number two.
Sprawl beneath, shading the soil, smothering weeds and keeping moisture in — sister number three.
Can be trained up the corn like beans, in a looser version of the same idea.
Uses the cool, shaded ground between the stems early in the season.
Ramble through the block, luring aphids away and bringing in pollinators.
Keep these apart
Share pests (corn earworm / tomato fruitworm) and both are greedy — keep them in separate beds.
Inhibits many plants generally; give it its own spot.
Flowers worth tucking in
The blooms that pull pests away and bring in the bees — beauty that earns its keep.
Sacrificial aphid trap that rambles happily through the block.
Pulls in bees and pollinators to the whole patch.
Bring in hoverflies and ladybirds to clear aphids.
Common questions
What are the Three Sisters?
A traditional planting of three crops that help one another: sweetcorn for height, climbing beans that scramble up the corn and fix nitrogen for it, and squash that sprawls across the ground to shade out weeds and hold in moisture. Grown together in one bed, they support each other and make brilliant use of the space.
Why should sweetcorn be planted in a block?
Sweetcorn is pollinated by the wind, which carries pollen from the tassels at the top of the plants down onto the silks of the cobs. Planting in a square block rather than a single row lets that happen evenly, so the cobs fill out fully — a thin row pollinates poorly and gives gappy cobs.
What should not be planted near sweetcorn?
Keep sweetcorn away from tomatoes, with which it shares pests like corn earworm and competes for nutrients, and from fennel, which inhibits many neighbours.
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