Read the spacing range before you mark anything
The linked guide gives a range, not a single required number. Within-row seed spacing can be anywhere from 1 to 2 inches, and row-to-row spacing can be anywhere from 12 to 24 inches. Those are two different measurements, so decide each one explicitly and write it down before marking.
The within-row figure describes sowing positions for seeds. It is not a spacing for established plants, and it is not a thinning rule. If you are marking where seeds go, use the seed spacing you selected. Keep sowing, thinning and established-plant decisions separate rather than applying one number to all three.
A single counted row is a geometrical unit for planning and seed counting. It is not an entire garden layout. Supports and access still need space outside this single-row count, and adjacent rows need their own row-to-row interval chosen from the source range.
- Write down your chosen within-row seed spacing from the 1 to 2 inch range.
- Write down your chosen row-to-row spacing from the 12 to 24 inch range.
- Label the row length you measured and the end margins you plan to leave.
Source context: Utah State University Extension
Worked example: one 96-inch row at 2-inch centers
This is a clearly labeled geometrical example, not crop advice for every garden. Take one measured row 96 inches long. Select 2-inch centers within the row and a 1-inch margin at both ends. The first sowing position falls 1 inch from the start, the last falls 95 inches from the start, and the row holds 48 sowing positions.
The counted item is sowing positions, meaning the marked points where seeds would be placed. It is not a plant count after thinning, not a harvest estimate, and not a yield figure. The 2-inch choice sits at the wider end of the 1 to 2 inch range; the source does not say this point is better than another.
The example does not set row-to-row spacing, support placement or access width. Those must be chosen separately from the context and your own garden measurements.
- Measure the row length in inches or centimeters.
- Subtract both end margins from the row length.
- Divide the remaining length by the selected center spacing, then add one to count positions.
- Check that the first and last marked centers match the margins you intended.
Source context: Utah State University Extension
Count the row with the linked calculator
The linked row calculator can count this exact length, center interval and both end margins, in inches or centimeters. Enter the measured row length, the selected within-row center spacing and the margin at each end. The output is the number of sowing positions along that one row.
Use the calculator for one row at a time. If your plan has several rows, count each row separately and then choose the row-to-row interval from the 12 to 24 inch range. Do not multiply a single-row count into a garden total without deciding how many rows fit and how much space supports and access require.
- Enter the row length in your chosen unit.
- Enter the selected center spacing within the 1 to 2 inch range.
- Enter both end margins.
- Record the returned sowing-position count for that row only.
Source context: Utah State University Extension
Decide what the row count leaves out
Supports and access still need space outside this single-row count. The source does not supply a support distance or an access width, so choose those separately based on your garden and the support you plan to use. Do not assume the row interval covers them.
Adjacent rows need their own spacing decision within the 12 to 24 inch range. Mature habit also matters when you plan the layout, but the linked guide does not give a mature-plant spacing figure. Keep the seed spacing, row spacing and layout choices as separate notes so the plan stays checkable.
- Mark the space reserved for supports outside the counted row.
- Mark the access path you need.
- Choose and record the row-to-row interval for any adjacent row.
- Review the layout against the source range before sowing.
Source context: Utah State University Extension
Check your measured example
One measured 96-inch row, with selected 2-inch centers and 1-inch margins at both ends. Count 48 sowing positions.
Reference and growing system: USU gives pea seeds 1–2 inches apart within rows 12–24 inches apart. Supports and access still need space outside this single-row count.
| Quantity | Calculated result |
|---|---|
| Usable row length (in) | 96 |
| Selected center spacing (in) | 2 |
| Margin at each row end (in) | 1 |
| Positions in this row | 48 |
| First center from row start (in) | 1 |
| Last center from row start (in) | 95 |
| What is being counted | sowing positions |
The example uses a 96-inch row, 2-inch centers and 1-inch margins at both ends, giving 48 sowing positions with the first at 1 inch and the last at 95 inches. It is a geometrical count of sowing positions for one row, not a recommendation for every garden, and it does not set row-to-row spacing, support placement or access width.
Count this row in the spacing calculator ↗Example inputs explain the method. Review the source context, chosen cultivar and actual site before planting or ordering.
Your before-you-plant checklist
- Within-row seed spacing is recorded from the 1 to 2 inch range.
- Row-to-row spacing is recorded from the 12 to 24 inch range.
- The measured row length and both end margins are written down.
- The counted item is labeled as sowing positions, not established plants.
- Space for supports and access is marked outside the single-row count.
Questions that come up while planning
How far apart should pea seeds be within a row?
The linked guide gives 1 to 2 inches apart within rows. Choose one point in that range, record it, and use it consistently when marking sowing positions.
Does the 48-position example mean 48 plants?
No. The example counts sowing positions along one 96-inch row at 2-inch centers with 1-inch end margins. It does not predict germination, thinning results or established plant numbers.
Can I use one row count as my whole garden plan?
No. A single row is a geometrical unit. Row-to-row spacing, supports and access must be chosen separately, and the source does not supply support or access distances.
Sources & method
Horticultural guidance is linked to its original source and regional context. Geometry and unit conversions are calculated separately. Read how we prepare and check a page.
- How to Grow Peas in Your GardenUtah State University Extension