Can I Plant Two Kinds of Corn Beside Each Other?

Cross-pollination

• Wind-blown corn pollen travels long distances, so if corn grows near your garden you'll always run some risk of cross-pollination problems. Planting varieties no closer than 400 yards apart effectively isolates corn, but small gardens don't provide that much space. If you plant varieties of corn that flower earlier or later than the neighboring crops, the corn plants in the plot pollinate one another and the crop stays true. In side-by-side plantings, choose corn varieties that mature at least 30 days apart to prevent cross-pollination.

Block Plantings

• The way corn rows lie in the garden affects the pollination rate of the corn. Ears with few kernels show that not enough pollen reached the female blossom during the bloom. One row of corn may produce nothing if during the blooming period the wind blew pollen away from the row instead of through it. Successful corn crops in small gardens depend on block plantings of at least three rows, says the Arizona Cooperative Extension. A four-row block pollinates more thoroughly, so if possible plant four rows of each variety.

Hybrids

• Hybrid corn gives gardeners with small plots the best chance of producing pure side-by-side corn crops. Hybrid corn flowers over a short period so the ears of corn all ripen at nearly the same time and allow a single harvest. This short blooming period makes separating strains by blooming date more effective. Staggering the planting dates gives a longer gap between blooming dates. Planting one variety later in the spring risks maturing that crop during summer heat and drought, both of which reduce yields.

Open-pollinated Corn

• Older open-pollinated strains of corn produce seed with the same genetic structure as the parent corn, so seed-savers can replant from their own crops with predictable results. Open-pollinated corn blooms over a longer period than does hybrid corn, making isolation much trickier. Planting a fast-growing, early strain first, followed by a long-season variety, still allows growers two crops with good genetic separation. "Golden Bantam" sweet corn matures in from 70 to 85 days, while Stowell's Evergreen matures in 80 to 100. Planting Stowell's Evergreen 20 days after planting Golden Bantam provides the minimum bloom separation.