Plant Population
Enter field area, plant spacing, row spacing, walkway width and plants per stand to compute total plants and density per m², for seedling demand and yield planning.
Input Data
Results
At a glance:Plant population is the total plants a field can hold under a given spacing layout — the basis for planning density, estimating seedling demand and comparing yield. The principle: find each plant's 'ground footprint' area — along the row it is (plant spacing + walkway width), across rows it is row spacing — then divide field area by footprint area and multiply by plants per stand: total plants = field area × plants per stand ÷ ((plant spacing + walkway width) × row spacing). Density (plants/m²) is total plants ÷ field area. Denser planting raises per-area yield but also competition, poor ventilation and disease risk, so balance by crop traits.
Formula
Per-plant footprint area: A₁ = (plant spacing + walkway width) × row spacing.
Total plants: N = field area × plants per stand ÷ A₁.
Plant density: ρ = N ÷ field area.
$$A_1 = (s + w) \times r$$$$N = \frac{A_{field} \times p}{A_1}$$$$\rho = \frac{N}{A_{field}}$$How to Use
- Enter field area (1 ha = 10,000 m²), plant spacing and row spacing (m).
- Enter walkway width if aisles are reserved between/within rows; enter plants per stand for multi-plant setting.
- The tool returns total plants and density per m² for seedling purchase and layout.
Approximate planting density of common crops
| Crop | Spacing (plant × row) | Approx. density (plants/m²) |
|---|---|---|
| Lettuce (leafy) | 0.25 × 0.25 m | ~16 |
| Tomato | 0.4 × 0.8 m | ~2.5–3 |
| Maize | 0.2 × 0.75 m | ~6–7 |
| Chinese cabbage | 0.4 × 0.5 m | ~5 |
| Strawberry | 0.3 × 0.3 m | ~9–11 |
Density varies with cultivar, pruning and machinery needs; values are common approximations — follow agronomic recommendations in practice.
Case Studies
Planting scale of 1 ha tomatoes
1 ha (10,000 m²) tomatoes: plant spacing 0.4 m, row spacing 0.8 m, row walkway 0.1 m, single plant.
Footprint = (0.4 + 0.1) × 0.8 = 0.4 m²; total plants = 10,000 × 1 ÷ 0.4 = 25,000.
Density = 25,000 ÷ 10,000 = 2.5 plants/m², from which seedling purchase and trellis materials are estimated.
Urban farm with multi-plant stands
An urban-farm bed 800 m²: spacing 0.4 m, row 0.8 m, walkway 0.1 m, 2 plants per stand.
Footprint = 0.4 m²; total plants = 800 × 2 ÷ 0.4 = 4,000.
Double plants per stand doubles density in limited area, but strengthen ventilation and fertility management.
FAQ
How are plant spacing, row spacing and walkway width split?
Plant spacing is the distance between two adjacent plants in the same row; row spacing is between two adjacent rows. Walkway width is an extra gap reserved per plant along the row for harvest or machinery, added to plant spacing as the plant's length along the row. With no walkway, enter 0 and the formula reverts to field area ÷ (plant spacing × row spacing).
Why multiply by plants per stand?
Some crops are 'stand-planted' — several plants per point (e.g. twin-plant). Then each footprint holds more than 1 plant, so total plants multiply by plants per stand. Single planting enters 1 (no effect); stand planting enters the real count to reflect densification.
Is a fractional plant count normal?
Yes. The area division often yields a decimal, the theoretically maximum plants. In practice round down (no half-plants) and subtract bunds, irrigation lines and turning space, so actual planting is usually a bit below the theoretical value, used as a purchase ceiling.
Does higher density always mean higher yield?
Not necessarily. More density adds plants per area, but too dense intensifies competition for light, water and nutrients and lowers ventilation, raising disease risk, possibly dropping per-plant yield and quality. Optimum density depends on crop, cultivar and goal (fresh or processing), set by field trials — not the denser the better.
Is this calculator suitable for Hong Kong's small farms?
Yes. Hong Kong farmland is fragmented and urban/rooftop farms are limited in area; precise plant population helps optimize layout in small areas, control seedling cost and estimate yield. Enter the actually measured field area and spacing, and remember to reserve harvest walkways and borders so the result better matches real plantable count.
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References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.