Last Updated on September 17, 2026

How Many Corn Plants per Square Foot?

4 corn plants per square foot, set 6 inches apart each way, and planted as a block of squares, never one square on its own. That is the number on my square foot gardening chart and in the Plan My Garden planner. What changes it is how much room each stalk needs to fill its ears, and whether the block is big enough to pollinate.

The spacing pattern

Bed counts are grid maximums for a bed planted all in corn, not a target; most gardens give corn one block of the bed. The ears assume one per stalk, what Utah State University Extension says to expect. Illinois Extension ties the second, smaller ear to good conditions including correct spacing, so at 6 inches treat it as a bonus.

Why guides say 2, 4 or 9 corn plants per square foot

Each comes from a different way of spacing corn:

Against garden rows, most of the gap is the 30 to 36 inches between rows, which a square foot bed does not have. Illinois Extension and Utah State both list plants too close together as a cause of ears that do not fill to the tips, along with dry weather at silking, low fertility and poor pollination. Utah State also notes that corn spaced far apart in the row sends up more suckers, and that planting closer increases ear yield, which is why a bed with no wide paths can hold more plants than garden rows. At 4 inches, 9 per square is the closest spacing here and the most likely to crowd ears, so skip it. Stay at 4 and water steadily. The looser 2 per square from the Mel Bartholomew class notes below is the option to try next time if tips still come up short.

Plant a block, not a single square

Wind carries corn pollen from the tassel to the silks. University of Minnesota Extension says to always plant blocks of at least four rows, because a single row loses much of its pollen and gives ears with blank spots where kernels did not form. Utah State asks for three or more rows and Illinois Extension for two or more, so four rows covers all three. At 4 per square, one square is only two short rows. A block 2 squares deep gives four rows, the minimum, and a block across a 4-foot bed gives eight. My 4×4 raised bed layout goes further and keeps corn out of a 4×4 bed, since it wants a block bigger than 4×4 to pollinate: give it a second bed or a 4×8.

Put the block on the north side: NC State Extension groups tall crops like corn there so they do not shade shorter plants. The Plan My Garden planner lists corn at about 90 inches tall.

Planting the block

1. Mark a block on the north side of the bed, at least 2 squares deep.
2. Wait for warm soil: Illinois Extension wants soil above 55°F for standard sweet corn and about 65°F for supersweet types.
3. In each square, sow four seeds 1 inch deep (the depth Minnesota Extension gives), 3 inches in from the edges, so plants sit 6 inches apart.
4. Cover the block with floating row cover until seedlings are up; Minnesota Extension says it discourages birds that eat the seed.
5. Water about 1 inch a week, which Minnesota Extension says is good for corn, and never let the block dry out at tasseling and silking, when Illinois Extension says lack of water cuts quality and yield.

When to plant corn

These are the windows the Plan My Garden planner uses, counted from your average last spring frost. Turn the weeks into dates with the seed starting calendar, or enter your zip code on Plan My Garden.

Soil temperature for germination

From my Seed Germination Temperature Chart: corn germinates from 50°F, does best at 65-95°F, and stops above 105°F. Days for sweet corn seedlings to emerge, from the same chart:

Growing notes

Minnesota Extension suggests improving the soil with well-rotted manure or compost in spring or fall, and not using fresh manure. Per Illinois Extension, removing side shoots takes time and does not improve yields. Ears are ready at the milk stage, about 20 days after the first silks appear, when the silks are turning brown and a kernel punctured with a thumbnail gives milky juice.

Minnesota Extension also says to isolate different types of corn to prevent cross-pollination: a shrunken (supersweet) type crossed with any other type gives starchy, tough kernels. Grow one type, or keep types apart in space or planting time.

Where to get seed

Wood Prairie’s organic corn seed includes two open-pollinated sweet corns, Orchard Baby, 67 days, with compact 3 to 4 foot stalks and two ears about 4 inches long, and Dorinny, 75 days, on 4 to 5 foot plants with 6 to 7 inch cobs. Both are much shorter than the 90 inches the planner lists for corn, which keeps a block from shading the rest of a bed. Code PMG5 takes 5 percent off.

Quick questions

How many corn plants fit in a 4×8 raised bed?

Up to 128 at 4 per square foot, in 8 rows of 16, if the whole bed is corn. Plan on about one ear per stalk.

What is corn spacing in square foot gardening?

6 inches apart each way, which is 4 plants per square. Notes from a Mel Bartholomew class list 2 per square, a looser option if ears have not filled out at 4.

Can I plant just one square of corn?

Not for good ears. University of Minnesota Extension says to plant blocks of at least four rows so the wind can pollinate them, and one square holds only two short rows. Plant a block at least 2 squares deep.

How many ears of corn does one plant make?

Plan on one, as Utah State University Extension advises. Illinois Extension says many varieties add a second, smaller ear under good growing conditions.

Let the planner place them

Plan My Garden is free to start: enter your zip code, draw your beds, pick corn and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates.

Related: Square Foot Gardening Chart · Seed Starting Calendar · 4×8 Raised Bed Garden Layout · How Many Tomato Plants per Square Foot?