How accurate are these yield estimates?

These are average UK yields for well-managed plots. Actual yields depend on soil quality, weather, variety, and how well you tend the crops. Experienced growers can exceed these figures.

What gives the highest yield per m²?

Cordon tomatoes (around 6 kg/m²) and courgettes (around 5 kg/m²) are the highest-yielding crops here. Potatoes give good total weight (about 3.5 kg/m²) but need more space per plant. Leafy crops like lettuce yield the least by weight.

How do I improve my vegetable yields?

Good soil preparation, regular watering, proper spacing, timely feeding, and pest control all improve yields significantly.

Which vegetables are best for beginners?

Courgettes, runner beans, lettuce, radishes, and potatoes are all forgiving crops ideal for new growers in UK conditions.

What affects vegetable yield the most?

Soil quality, consistent watering, sunlight (6+ hours), and feeding are the biggest factors. Protected growing (greenhouse/fleece) and succession planting also boost total harvests.

GardenCalcs.uk

Crop Yield Calculator — Estimate Vegetable Harvest

Estimate harvest yields for common vegetables based on growing area.

CropPick the vegetable to estimate — each uses average UK kg/m² yields and RHS spacing

Growing Area

Total bed or plot area given to this one crop, in square metres (e.g. a 2 × 3 m bed = 6 m²)

Growing ExperienceScales the yield: beginner ~60%, average ~85%, experienced 100% of optimal

How We Calculate This

Yield = Area x Yield per m² x Skill Factor. Average yields are based on UK growing conditions with typical varieties.

Skill factors: beginner 60%, average 85%, experienced 100% of optimal yield.

Plant counts use recommended RHS spacings (e.g. potatoes and cordon tomatoes ≈ 0.25 m² each, courgettes ≈ 1 m², carrots and onions ≈ 0.01 m²). Harvest window shows how long the crop typically produces for.

Yield figures are average UK allotment kg/m² ranges (RHS grow-your-own guides, growveg.co.uk and gardenuk.co.uk) — for example tomato 5-10, courgette 5-8, potato 2-5, carrot 3-5 kg/m². Treat results as a planning estimate, not a guarantee.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.