Sweet Corn + Summer Squash

Corn and summer squash are two thirds of the traditional Three Sisters combination, and the pairing holds up well on its own merits. Squash leaves spread wide and shade the soil beneath the corn canopy, reducing weed germination and slowing moisture loss during dry mid-summer stretches. The coarse, spiny stems provide some deterrence against raccoons working through a corn block.

Spacing requires attention. Corn needs blocks of at least four rows wide for adequate wind pollination. Plant squash hills every 3 to 4 feet along the outer perimeter or between rows, with at least 18 inches of clearance from corn stalks so access for hilling and harvest remains workable. Stagger planting by two to three weeks, giving corn a head start before squash vines begin to sprawl.

Both crops are heavy feeders; soil with good organic matter and available nitrogen is important, since squash shows nitrogen stress quickly. In small gardens, sprawl is the limiting factor. Bush-type summer squash varieties are a more practical fit than vining types where space is tight.