Read the source range before choosing a number
The reference sets two separate dimensions: 18–24 inches between broccoli plants within a row, and 36 inches between rows. The in-row range is a choice, not a single fixed value. The 36-inch figure describes row separation; it does not set bed width, path width, or the distance from a bed edge to the first plant.
Choose one in-row interval and record it before marking. The narrower end of the range and the wider end both sit inside the source context, but they produce different plant counts on the same row length. Your choice should reflect the space you want between established plants, not the spacing you use at sowing or thinning.
- Write down the chosen in-row interval from the 18–24 inch range.
- Record the 36-inch row separation separately from the in-row interval.
- Keep the chosen values with your garden notes so later rows use the same assumptions.
Source context: Clemson Cooperative Extension
Sowing, thinning and initial planting are not the final spacing
Spacing at sowing can differ from the final arrangement of established plants. Thinning is the step where seedlings are reduced so the remaining plants sit at the chosen in-row interval. Initial planting of transplants should place them at that same final interval.
Treat the marked centers as the target for established plants. If you sow more densely and thin later, the final count is what the spacing plan describes. Do not confuse the number of seeds sown with the number of plants the row is planned to hold.
- Mark final plant centers at the chosen in-row interval.
- Thin seedlings or set transplants so established plants match those centers.
- Check the row after thinning against the planned count.
Source context: Clemson Cooperative Extension
Worked example: one 144-inch row at 24-inch centers
The example uses a 144-inch row, a selected 24-inch center interval, and 12-inch margins at both ends. With those inputs, the first center falls at 12 inches and the last at 132 inches, giving 6 counted positions. The counted item is plants.
This is a geometrical example, not a recommendation to use 24 inches in every garden. It shows how one row length, one chosen interval from the source range, and both end margins produce a plant count. The 12-inch margins are example inputs, not a spacing rule from the source.
One row is not an entire garden layout. The example does not decide how many rows fit, how far apart they sit beyond the 36-inch reference, or how much access space surrounds them.
- Measure the row length in inches or centimeters.
- Enter the chosen center interval and both end margins into the row calculator.
- Confirm the first and last center positions and the counted plants before marking.
Source context: Clemson Cooperative Extension
Decide the remaining layout questions separately
Access, supports, adjacent rows, and mature habit must be chosen for your own site. The source gives row separation of 36 inches, but it does not supply path widths, bed-edge distances, or support dimensions. Decide those separately and record them rather than borrowing numbers from the example.
If you plan more than one row, apply the 36-inch row separation as the reference between rows and then check that your access and adjacent plant needs are met. The row calculator counts positions along one measured length; it does not lay out a whole garden.
- Choose access and edge distances for your site and write them down.
- Apply the 36-inch row separation when planning additional rows.
- Check each row's plant count separately before finalizing the layout.
Source context: Clemson Cooperative Extension
Check your measured example
One measured 144-inch row, with selected 24-inch centers and 12-inch margins at both ends. Count 6 plants.
Reference and growing system: Clemson gives broccoli 18–24 inches apart within rows 36 inches apart.
| Quantity | Calculated result |
|---|---|
| Usable row length (in) | 144 |
| Selected center spacing (in) | 24 |
| Margin at each row end (in) | 12 |
| Positions in this row | 6 |
| First center from row start (in) | 12 |
| Last center from row start (in) | 132 |
| What is being counted | plants |
The example uses a 144-inch row, 24-inch centers, and 12-inch margins at both ends. The first center is at 12 inches, the last at 132 inches, and the calculator counts 6 plants. The 24-inch interval is one selected point within Clemson's 18–24 inch in-row range; the margins are example inputs, and the result describes one row rather than a full garden layout.
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
- Chosen in-row interval recorded from the 18–24 inch range.
- Row separation noted as 36 inches where additional rows are planned.
- Row length, center interval, and both end margins entered in the calculator.
- First and last center positions checked against the marked row.
- Plant count confirmed as plants, not seeds or seedlings.
Questions that come up while planning
What in-row spacing does Clemson give for broccoli?
Clemson gives broccoli 18–24 inches apart within rows that are 36 inches apart. Choose one interval from that range and record it before marking plants.
Does the 144-inch example recommend 24-inch spacing?
No. It is a geometrical example using a selected 24-inch center interval and 12-inch end margins. It shows how those inputs produce 6 plant positions, not a crop recommendation.
Does one counted row describe my whole garden layout?
No. The count covers plants along one measured row. Row separation, access, supports, adjacent rows, and mature habit must be decided separately.
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.
- BroccoliClemson Cooperative Extension