Formula used
Garden area
Rectangle area equals length multiplied by width. Circle area equals π multiplied by radius squared. Triangle area equals one-half multiplied by base and height.
Plant quantity
Plant quantity equals net plantable area divided by spacing area. Triangular spacing multiplies spacing area by 0.866. The loss allowance increases the final quantity.
Soil material volume
Material volume equals net area multiplied by material depth. Imperial cubic feet convert into cubic yards. Metric calculations remain in cubic metres.
Water need
Weekly water equals plants multiplied by water per plant and frequency. Rainfall reduces the demand. Irrigation efficiency increases the delivered requirement.
Overall pollinator score
The score combines native plants, diversity, blooms, habitat, water, density, pollinator range, and pesticide-free management. Higher values indicate stronger support. Local ecology still determines final suitability.
How to use this calculator
1. Measure the garden
Choose a garden shape and enter its dimensions. Add repeated sections when needed. Subtract paths, seating, stones, and utilities.
2. Define planting density
Enter mature spacing and the planting pattern. Add a loss allowance for failed plants. Use cluster settings for repeated flower groups.
3. Balance habitat and blooms
Select pollinators, plant groups, and habitat features. Spread blooms across all seasons. Prefer locally native and pesticide-free choices.
4. Review materials and costs
Enter water, soil, prices, and maintenance time. Submit the form for a complete plan. Review every warning before purchasing materials.
Example garden data
| Input | Example | Purpose |
|---|---|---|
| Garden size | 20 ft × 12 ft | Calculates gross area |
| Reserved area | 10% | Removes non-planting space |
| Plant spacing | 18 in triangular | Estimates plant quantity |
| Native species | 12 of 16 | Measures native percentage |
| Bloom allocation | 15%, 25%, 35%, 25% | Checks seasonal continuity |
| Compost depth | 2 in | Estimates amendment volume |
| Plant price | £4.50 | Builds the project budget |
Pollinator garden planning guidance
Use locally native plants whenever practical. Native plants often match local pollinator life cycles. They can also reduce long-term maintenance needs.
Provide flowers from early spring through autumn. Use several species during every bloom period. Repeated clusters make flowers easier to locate.
Include nesting sites, shallow water, shelter, and leaf litter. Avoid systemic insecticides near flowering plants. Local advice should guide final plant choices.
Frequently asked questions
How many plants should a pollinator garden contain?
The answer depends on area, spacing, mature spread, and planting pattern. This calculator estimates a practical quantity. Always check each plant's mature size.
Why does triangular spacing fit more plants?
Triangular spacing staggers rows and uses space efficiently. It usually increases planting density. Mature spread must still prevent overcrowding.
What native plant percentage is recommended?
A strong target is sixty percent or more. Higher local native content often supports specialised insects. Regional guidance may recommend different targets.
How many species should bloom each season?
Use at least three flowering species per season. More diversity improves resilience and food choice. Include different flower shapes and colours.
Should every garden include host plants?
Host plants support butterfly and moth larvae. Nectar plants alone cannot complete their life cycles. Match host plants with local target species.
Why are bare soil patches useful?
Many native bees nest inside bare ground. Keep patches sunny, undisturbed, and pesticide-free. Avoid thick mulch across every garden surface.
How accurate is the water estimate?
It is a planning estimate, not a watering schedule. Soil, rainfall, climate, and plant age change demand. Check soil moisture before irrigating.
Can seeds and plugs be compared directly?
Seeds cost less but establish less predictably. Plugs provide faster and more reliable coverage. Mixed methods often balance cost and success.
What does the habitat score measure?
It measures the variety of selected habitat features. It does not assess their exact quality. Placement and maintenance remain very important.
Why does the calculator warn about coverage?
Low coverage can leave weeds and exposed soil. Excessive coverage can create competition and disease. Mature dimensions improve the estimate.
Does this calculator replace local planting advice?
No. Climate, soils, invasive species, and regulations vary. Confirm plant choices with trusted regional gardening resources.
Important note
This calculator provides planning estimates only. Local plant suitability, rainfall, wildlife, and regulations can differ. Confirm final selections with regional experts.