How Far Apart to Plant Potatoes

Twelve inches is the number to remember for potatoes. That single figure, in rows about 30 inches apart, is what Utah State and Maryland Extension both land on for a home garden. The rest of this guide is when to go tighter and what it costs you.

Potatoes are not like lettuce, where tighter is mostly fine. Each plant needs soil pulled up over its stems as it grows, and that hilling soil has to come from the row beside it. Spacing potatoes is really about leaving room for the hill.

Spacing in rows vs a raised bed

The right number changes with how you garden. A traditional row and a square-foot bed are two different jobs.

For rows, plant seed potatoes 12 inches apart in rows 30 to 36 inches apart, per Utah State University Extension. The wide rows are not wasted space. You need that soil to hill up over the stems as the plants grow.

For a raised bed or square-foot garden, the grid tightens. The square-foot method counts potatoes at about 4 per square foot, which works out to roughly 6 inches between plants.

That tighter spacing is a real trade. At 6 inches you get more plants but smaller tubers, which is fine if you are after small new potatoes. Utah State notes the closer spacing of about 6 inches suits baby potatoes harvested young. For full-size storage potatoes, give each one the full 12 inches.

If you are filling that bed first, our plant spacing chart lists the in-row inches and square-foot counts for every crop in one place.

Potato spacing by method, at a glance

Pick how you grow, then read the spacing and the count for a standard 4x8 bed across. These figures come from Utah State and Maryland Extension guidance, and the bed counts are computed for a 4x8 (32 square foot) bed.

The pattern is simple. The more tubers you want, the closer you plant. The bigger you want each potato, the more room it needs.

Square vs triangular layout

How you arrange the plants, not just how far apart, changes how many fit. A triangular (offset) grid packs in roughly 15% more plants than a straight square grid over a large area.

In a square grid, every plant lines up in neat rows and columns. In a triangular grid, each row shifts over by half a space, so plants nestle into the gaps of the row beside them. That offset is what buys the extra density.

The catch is bed size. In a small bed the edges eat the gain. A 4x8 bed at 12-inch spacing fits 32 plants square but 30 triangular, because the offset rows lose a couple of plants to the short side. The 15% edge only shows up once the bed is big enough for the pattern to repeat.

square grid (4x8 bed, 12in)      triangular grid
● ● ● ● ● ● ● ●                  ● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ●                   ● ● ● ● ● ● ●
● ● ● ● ● ● ● ●                  ● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ●                   ● ● ● ● ● ● ●
= 32 plants                      = 30 plants

Run your own bed size through the Plant Spacing Calculator and it counts both layouts, so you can see which wins for your exact dimensions.

Why spacing matters for potatoes

Spacing decides three things for potatoes: tuber size, airflow, and disease. Crowd the plants and all three move the wrong way.

Give each plant 12 inches and it has room to bulk up full-size tubers and to throw foliage that dries fast after rain. Squeeze them to 6 inches and the canopy stays damp, which is where late blight and early blight take hold.

Maryland Extension ties good spacing and hilling to healthier plants and a cleaner harvest. Wet, crowded foliage is the opposite of what you want when blight is the main threat to a potato crop.

Common spacing mistakes

A few errors show up again and again in potato beds. Each one is easy to avoid once you know the number.

• Planting closer than 12 inches and ending up with marble-sized tubers.
• Crowding the rows tighter than 30 inches, leaving no soil to hill with.
• Setting seed pieces too shallow, so tubers form near the surface and turn green.
• Treating square-foot spacing as free when it shrinks every potato in the bed.

The fix for all four is the same. Plant at 12 inches for full-size potatoes, keep rows at 30 to 36 inches so you can hill, and only tighten the spacing if small new potatoes are the goal.

If you are buying more than a few pounds of seed, measure your beds first and order to the row-foot. For potatoes specifically, run your bed through the Plant Spacing Calculator at 12-inch spacing, set the layout to match how you plant, and order exactly that many seed pieces. Once they are in the ground, when to harvest potatoes picks up the rest of the season.