Petunia Spacing
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GardenSays
Your 8×4 ft raised bed fits 32 petunias at 11-inch spacing.
- Between plants
- 11 in
- Grid
- 8 × 4
- Total plants
- 32
Petunias need 10-12 inches between plants, and in a raised bed you can use that same spacing in both directions — no walking rows needed. At the 11-inch midpoint, that's 8 along the bed and 4 across — 32 plants.
Calculated result · 1 verified source · Checked 2026-07-18 · How we decide
Why
Crowding is the most common spacing mistake: closer planting doesn't add yield, it adds shade, disease pressure, and small fruit. When in doubt, use the wider end of the range.
- Air circulation between mature plants is the cheapest disease prevention there is.
- Roots spread wider than the plant looks in June — spacing is set for August size.
When this doesn't apply
- Compact petunias can take the tight end of the range; large or vigorous ones want the wide end.
- Square-foot gardening compresses further than these numbers — it trades yield per plant for yield per bed and needs diligent feeding.
How this was calculated
- 1. In-row spacing11 in
Petunia: 10-12 inches between plants (extension guidance); midpoint used
- 2. Intensive grid8 × 4 plants
Raised beds skip walking paths: plants sit on a 11×11 inch grid. 96÷11 along, 48÷11 across (edge margins included in the division)
- 3. Total32 plants
8 × 4
Data sources
- University of Minnesota Extension — Growing petunias — Space grandifloras and multifloras about 12 inches apart in full sunlight, or several inches closer in a shadier location. (checked 2026-07-18)
What changes this answer
Layout
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Bed width (ft)
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