Vegetable Garden Plant Spacing Calculator
The Vegetable Garden Plant Spacing Calculator gives you the exact recommended distance between plants based on the crop you are growing. Proper spacing is set by each plant's mature canopy width, root spread, and light requirements. The core rule: in-row spacing ≈ mature plant width × 1.0–1.2, while row spacing ≈ plant height × 0.75–1.0. Get it wrong and you risk overcrowding (poor airflow → fungal disease) or wasted bed space. Use this tool when planning a new garden bed, transplanting seedlings, or converting a traditional row garden to a raised-bed or square-foot layout.
Tomatoes need 60–80 cm between plants and 90–120 cm between rows. Carrots: 5–8 cm. Lettuce: 25–30 cm. Potatoes: 25–35 cm. Squash: 90–120 cm. General rule: in-row spacing = mature plant width × 1.0–1.2; row spacing = plant height × 0.75–1.0.
When to use this calculator
- Planning a raised bed to maximize yield per square foot without overcrowding tomatoes, peppers, or squash
- Converting a traditional single-row vegetable garden to a denser square-foot or block-planting layout
- Calculating seed packet quantities before purchasing: knowing spacing lets you compute exactly how many plants fit your bed dimensions
- Timing thinning operations for direct-seeded crops like carrots, beets, and radishes after germination
- Designing a companion-planting layout where spacing between species must accommodate both plants' canopy widths simultaneously
Worked Example: Tomatoes in a 4 ft × 8 ft Raised Bed
- Select: Tomato → recommended spacing: 60–80 cm between plants
- Bed dimensions: 120 cm × 240 cm
- Plants per row: floor(240 ÷ 75 cm) = 3 plants
- Rows that fit: only 1 row at 90 cm row-spacing in a 120 cm-wide bed
- Result: 3 indeterminate tomatoes — any more risks disease and yield loss
How it works
4 min readHow Plant Spacing Is Calculated
Plant spacing is derived from each crop's mature canopy diameter and root competition radius. The formulas used by cooperative extension services:
In-Row Spacing (cm) = Mature Plant Width (cm) × 1.0 to 1.2
Row Spacing (cm) = Plant Height (cm) × 0.75 to 1.0
Plants per m² = 10,000 cm² ÷ (In-Row Spacing × Row Spacing)For square-foot gardening (SFG), divide a 30 cm × 30 cm grid:
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Complete Vegetable Spacing Chart
| Vegetable | In-Row Spacing | Row Spacing | Plants/m² | Notes |
|---|---|---|---|---|
| Tomato (indeterminate) | 60–80 cm | 90–120 cm | 1–1.5 | Needs caging/staking |
| Tomato (determinate) | 45–60 cm | 75–90 cm | 2–3 | Bush type, self-supporting |
| Pepper (bell/hot) | 40–50 cm | 60–75 cm | 3–4 | Same family, similar needs |
| Eggplant | 45–60 cm | 75–90 cm | 2–3 | Needs full sun, deep root |
| Zucchini / Summer Squash | 60–90 cm | 90–120 cm | 1 | Sprawling vine |
| Winter Squash / Pumpkin | 90–120 cm | 150–180 cm | 0.3–0.5 | Large vine, needs room |
| Cucumber | 30–45 cm | 90–120 cm | 2–3 | Trellis = narrower spacing |
| Broccoli | 45–60 cm | 60–90 cm | 2–3 | Large head requires space |
| Cauliflower | 45–60 cm | 60–90 cm | 2–3 | Same as broccoli |
| Cabbage | 40–50 cm | 60–75 cm | 3–4 | Head size varies by variety |
| Lettuce (head) | 25–30 cm | 30–38 cm | 9–11 | Loose-leaf: 15–20 cm |
| Spinach | 8–15 cm | 30–38 cm | 18–25 | Thin to 15 cm at maturity |
| Carrot | 5–8 cm | 30–38 cm | 33–67 | Thin from ~2.5 cm seedlings |
| Beet | 8–10 cm | 30–38 cm | 26–42 | Each "seed" = cluster |
| Radish | 5–8 cm | 20–25 cm | 50–100 | Fastest: 22–30 days |
| Onion (bulb) | 8–10 cm | 30–38 cm | 26–42 | Sets vs. seeds same spacing |
| Garlic | 10–15 cm | 30 cm | 22–33 | Plant cloves point-up |
| Pea (bush) | 5–8 cm | 45–60 cm | 22–33 | Inoculate seed for N-fixation |
| Pea (climbing) | 5–8 cm | 60–90 cm | 17–25 | Provide trellis ≥1.2 m tall |
| Bean (bush) | 8–10 cm | 45–60 cm | 17–25 | Direct sow, no transplant |
| Bean (pole) | 15–20 cm | 90 cm | 5–7 | Groups of 3–4 at each stake |
| Sweet Corn | 25–35 cm | 75–90 cm | 3–5 | Plant in blocks ≥4 rows for pollination |
| Potato | 25–35 cm | 75–90 cm | 3–5 | Plant seed potato 10–15 cm deep |
| Sweet Potato | 30–45 cm | 90–120 cm | 2–3 | Trailing vine in warm climates |
| Basil | 20–30 cm | 30–45 cm | 7–11 | Pinch flowers to extend harvest |
Source: USDA NRCS Plant Guides; University Cooperative Extension spacing tables.
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Worked Examples
Case 1 — Tomatoes in a 4 ft × 8 ft raised bed
A standard 120 cm × 240 cm raised bed with indeterminate tomatoes spaced 75 cm apart fits:
Case 2 — Mixed salad greens in a 1 m² block
Using block planting at 20 cm spacing:
Case 3 — Sweet corn pollination block
Corn is wind-pollinated. A single row almost always produces poorly-filled ears. Minimum block: 4 rows × 4 plants = 16 plants. At 30 cm in-row × 75 cm row spacing, that requires a 1.2 m × 3 m area.
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Common Spacing Mistakes
1. Using in-row spacing as row spacing — Row-to-row distance is always wider than in-row spacing (typically 1.25–1.5×). Planting tomatoes at 60 cm × 60 cm instead of 60 cm × 90 cm creates a tunnel that traps moisture and causes early blight.
2. Ignoring variety — "Tomato" spacing varies from 30 cm (dwarf patio types) to 90 cm+ (indeterminate heirlooms). Always check the specific variety.
3. Not accounting for trellising — Cucumbers on a trellis can be spaced 30 cm apart; sprawling on the ground they need 60–90 cm. A trellis can effectively double planting density.
4. Skipping thinning on direct-sown crops — Carrots must be thinned to 5–8 cm after germination. Skipping thinning causes forked, stunted roots.
5. Applying ornamental pot spacing, not field spacing — Nursery pot tags may say "space 12 inches apart" for ornamental use. Productive vegetable gardens often use tighter block spacing to shade out weeds.
Frequently asked questions
How far apart should you plant tomatoes?
Indeterminate (vining) tomatoes need 60–80 cm between plants and 90–120 cm between rows. Determinate (bush) varieties can be planted 45–60 cm apart with 75–90 cm between rows. In a typical 4 ft × 8 ft (120 cm × 240 cm) raised bed, plant no more than 2–3 indeterminate tomatoes to allow adequate airflow and prevent early blight.
How far apart should you plant carrots?
Carrot seeds are sown 1–2 cm apart and thinned in two stages: first to 2.5 cm when seedlings are 5 cm tall, then to the final 5–8 cm when they reach 10 cm. Final in-row spacing of 5 cm yields standard carrots; 8 cm yields larger storage roots. Row spacing is 30–38 cm.
How far apart should lettuce be planted?
Head lettuce needs 25–30 cm between plants and 30–38 cm between rows, giving 9–11 plants per square meter. Loose-leaf varieties can be planted closer, at 15–20 cm. In a 1 m² block at 20 cm spacing, you can fit 25 plants.
How do I calculate how many plants fit in my raised bed?
Divide each bed dimension by the in-row spacing: Plants per row = floor(bed length ÷ in-row spacing). Number of rows = floor(bed width ÷ row spacing). Total plants = plants per row × number of rows. For example, a 2 m × 4 m bed with lettuce at 25 cm in-row and 30 cm row spacing: 16 plants × 6 rows = 96 lettuce plants.
What is square-foot gardening spacing?
Square-foot gardening (SFG) divides beds into 30 cm × 30 cm squares. Each square holds 1, 4, 9, or 16 plants depending on size: 1 for large plants (tomatoes, peppers), 4 for medium (lettuce, chard), 9 for small (spinach, beets), and 16 for tiny (carrots, radishes). SFG spacing is 20–30% denser than traditional row gardening because it uses deeply amended, loose soil.
How does plant spacing affect disease risk?
Tight spacing reduces airflow between plants, keeping foliage wet longer after rain or irrigation. Fungal diseases like early blight on tomatoes, powdery mildew on squash, and downy mildew on lettuce all proliferate in humid, stagnant-air environments. Increasing tomato spacing from 45 cm to 75 cm can reduce foliar disease incidence by 30–50% without significant yield loss per plant.
Why does sweet corn need block planting instead of a single row?
Sweet corn is wind-pollinated: pollen from tassels must fall onto silks. A single row means most pollen blows away, resulting in ears with missing kernels. The USDA recommends a minimum block of 4 rows × 4 plants (16 plants) for reliable pollination. Wider blocks (4+ rows) dramatically improve fill rates, especially in low-wind gardens.
How do I adjust spacing for container or pot gardening?
In containers, root volume is limited, so use the minimum of the recommended range. A 5-gallon pot (≈19 L) supports 1 pepper or 1 determinate tomato. A half-barrel (≈110 L) can hold 3–4 lettuce plants. Most vegetables need at least 30 cm of soil depth and 20–30 cm of lateral root room per plant.
What spacing is recommended for potatoes?
Potatoes should be planted 25–35 cm apart in the row, with 75–90 cm between rows. Plant seed potatoes (or cut tubers with at least one eye) 10–15 cm deep. This gives 3–5 plants per m². Closer spacing produces more, smaller tubers; wider spacing produces fewer, larger tubers.