Read the source range correctly
USU's Planting and Spacing section gives Brussels sprouts 12–18 inches apart within rows 24 inches apart. The 12–18 inch figure is the in-row interval between plants. The 24-inch figure is the distance between rows, not a plant-to-plant spacing within a row.
The range allows a choice rather than a single mandatory number. A tighter interval fits more plants in a given length; a wider interval leaves more room between plants. The source does not assign different intervals to different cultivars, bed widths or harvest dates, so do not invent those distinctions. Pick one interval, label it as your scenario, and keep it consistent through the plan.
- Write down the source range: 12–18 inches within the row and 24 inches between rows.
- Choose one in-row interval for your scenario and record why you chose it.
- Keep the chosen interval the same when you mark and count plants.
Source context: Utah State University Extension
Choose a labeled scenario and mark retained plants
For a clearly labeled example, use 18-inch centers within the row. This sits at the wide end of USU's 12–18 inch range. It is a geometrical planning choice, not a claim that 18 inches is better than 12 inches for yield, earliness or plant health.
Distinguish three stages. Sowing or thinning is when you remove seedlings so the retained plants end up at your chosen interval. Initial planting is when transplants or young plants are set at that interval. Established plants are the ones you keep through the season; the count below refers to those retained plants, not seeds sown and not seedlings thinned out.
Marking centers is more reliable than eyeballing gaps. Measure from one end, place the first center after the end margin, then repeat at the chosen interval. Check the last center against the far end margin before you commit.
- Label your scenario, for example: 18-inch centers, 9-inch end margins, one measured row.
- Measure the row length and both end margins before placing any marks.
- Mark each retained-plant center at the chosen interval and verify the final center against the far margin.
Source context: Utah State University Extension
Work the row example
The worked example is one measured row 144 inches long, with 18-inch centers and 9-inch margins at both ends. The first center falls at 9 inches and the last at 135 inches. Counting positions at 18-inch intervals from 9 to 135 inches gives 8 retained plants.
That count describes this one row only. It is not an entire garden layout, and it does not set the number of rows, the distance between adjacent rows, or access paths. USU's 24-inch between-row figure is separate from the in-row interval used here.
The linked row calculator can count this exact length, center interval and both end margins in inches or centimeters. Use it to check your own measured row rather than assuming the example transfers to a different length or margin.
- Enter the measured row length, chosen center interval and both end margins into the row calculator.
- Confirm the first and last center positions before accepting the count.
- Record the result as retained plants for that row, not as a whole-garden total.
Source context: Utah State University Extension
Decide what the row count does not cover
A single-row count leaves several choices to you. Access space for walking, watering and harvesting is not specified by the source, so decide it separately for your site. Supports or wind protection, if you use them, also need their own placement decision.
Adjacent rows need the between-row distance chosen separately from the in-row interval. USU gives 24 inches between rows, but that figure still has to be applied to your actual bed or garden arrangement. Mature plant habit matters too: the source range does not tell you how much clearance a particular planting will need at maturity.
Keep the counted item precise. The example counts retained plants in one row, not seeds, not seedlings, and not total garden capacity.
- Decide access space separately from the in-row interval.
- Apply the 24-inch between-row figure when laying out adjacent rows.
- Note any support or mature-habit clearance you choose, without inventing distances the source does not give.
Source context: Utah State University Extension
Check your measured example
One measured 144-inch row, with selected 18-inch centers and 9-inch margins at both ends. Count 8 retained plants.
Reference and growing system: USU’s Planting and Spacing section gives Brussels sprouts 12–18 inches apart within rows 24 inches apart.
| Quantity | Calculated result |
|---|---|
| Usable row length (in) | 144 |
| Selected center spacing (in) | 18 |
| Margin at each row end (in) | 9 |
| Positions in this row | 8 |
| First center from row start (in) | 9 |
| Last center from row start (in) | 135 |
| What is being counted | retained plants |
The worked example uses a 144-inch row, 18-inch centers and 9-inch margins at both ends. The first center is at 9 inches and the last at 135 inches, producing 8 retained plants. This is a geometrical count for one labeled row, not crop advice and not a whole-garden layout; the 18-inch choice sits within USU's 12–18 inch in-row range, while the 24-inch between-row figure is applied 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
- Source range recorded: 12–18 inches within rows, 24 inches between rows.
- One in-row interval chosen and labeled as your scenario.
- Row length and both end margins measured before marking.
- First and last center positions checked against the end margins.
- Count recorded as retained plants for that row, with access and adjacent-row choices noted separately.
Questions that come up while planning
What spacing does USU give for Brussels sprouts?
USU's Planting and Spacing section gives Brussels sprouts 12–18 inches apart within rows 24 inches apart. The first figure is the in-row interval; the second is the between-row distance.
Does the 144-inch example count seeds or seedlings?
It counts retained plants. With 18-inch centers and 9-inch margins at both ends, the first center is at 9 inches and the last at 135 inches, giving 8 retained plants in that one row.
Can I use one row count as my whole garden plan?
No. The count covers one measured row only. Access space, supports, adjacent rows and mature plant habit must be decided separately, and the 24-inch between-row figure still needs to be applied to your layout.
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 Brussel Sprouts in Your GardenUtah State University Extension