Read the source range before you mark
The linked guide gives two different measurements. The 24-inch figure is the spacing between watermelon transplants within a row. The 48-to-72-inch figure is the spacing between rows. Treat them as separate decisions: first choose your within-row centers, then choose row-to-row distance for your own access and mature-plant needs.
The source also notes that direct-sown mound groups are a separate system. Do not apply the 24-inch transplant figure to mound sowing as if the two methods were interchangeable. This guide covers transplants only.
- Write down the source's 24-inch within-row figure and the 48-to-72-inch between-row range.
- Decide which method you are using: transplants or direct-sown mound groups.
- Use the transplant figures only for the transplant method.
Source context: Utah State University Extension
Choose one labeled scenario and mark it
For a clearly labeled example, use 24-inch centers within one row. This is the point chosen for the worked scenario, not a claim that 24 inches suits every cultivar, bed or climate. The 48-to-72-inch between-row range still has to be chosen separately for your site.
Initial planting positions are not the same as established plants. When you mark transplants, you are placing the initial planting points. Later thinning or adjustment is a different step, and the count describes transplants placed at those points, not plants that survive or mature.
- Label your scenario, for example: one row, transplants, 24-inch centers.
- Mark the first center after the end margin, then repeat at 24-inch intervals.
- Record the between-row distance you chose separately from the within-row centers.
Source context: Utah State University Extension
Work through the 144-inch row example
The example row is 144 inches long. With 12-inch margins at both ends, the first center falls at 12 inches and the last at 132 inches. At 24-inch centers, that gives 6 counted transplants. The counted item is transplants, not seeds, mounds or established plants.
One row is not an entire garden layout. The example says nothing about how many rows fit in your space, how far apart those rows should be, or how adjacent rows interact with mature vines. Choose access paths, supports if any, adjacent-row distance and mature habit separately, using the source's 48-to-72-inch range as context rather than inventing a new number.
- Subtract both end margins from the row length before counting centers.
- Confirm the first and last center positions match your margin choice.
- Keep the row count and the between-row choice as separate notes.
Source context: Utah State University Extension
Use the row calculator for this exact count
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 24-inch center interval and the 12-inch margins at both ends to reproduce the 6-transplant example. Package label units govern any volume conversions; the calculator's length inputs do not change the source spacing facts.
Check that the calculator's counted item is transplants and that the output matches your marked positions before you rely on it.
- Enter 144 inches, 24-inch centers and 12-inch margins at both ends.
- Switch to centimeters if your tape measure uses them, keeping the same physical distances.
- Compare the calculator's count with your marked row before planting.
Source context: Utah State University Extension
Check your measured example
One measured 144-inch row, with selected 24-inch centers and 12-inch margins at both ends. Count 6 transplants.
Reference and growing system: USU’s Planting and Spacing section gives watermelon transplants 24 inches apart within rows 48–72 inches apart. Direct-sown mound groups are a separate system.
| 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 | transplants |
The example uses a 144-inch row with 24-inch centers and 12-inch margins at both ends. The first center is at 12 inches and the last at 132 inches, giving 6 counted transplants. This is a geometrical count for one labeled row, not crop advice or a complete garden layout; between-row distance, access, supports and mature habit must be chosen separately.
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
- Confirm you are planning transplants, not direct-sown mound groups.
- Label the scenario with row length, center interval and both end margins.
- Mark the first and last centers and check they match the margins.
- Keep the between-row distance as a separate choice within the range.
- Verify the calculator counts transplants and matches your marked positions.
Questions that come up while planning
How far apart should watermelon transplants be within a row?
The linked guide gives 24 inches apart within rows. Row-to-row spacing is given separately as 48 to 72 inches, so choose that distance for your own access and mature-plant needs.
Does the 144-inch example tell me how many rows to plant?
No. It counts transplants in one measured row only. It does not describe a full garden layout, between-row distance or how many rows fit your space.
Can I use the 24-inch figure for direct-sown mounds?
No. The source treats direct-sown mound groups as a separate system. The 24-inch transplant figure applies to transplants within rows.
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 Watermelon in Your GardenUtah State University Extension