GardenCalcs.uk
Propagation Calculator — Cuttings & Rooting Quantities
Work out how many cuttings to take, and how many pots you need, to end up with the number of rooted plants you want.
How We Calculate This
Formula: Cuttings to take = ceil(Plants wanted ÷ (Success rate ÷ 100)).
For example, wanting 20 plants at 70% success means taking 29 cuttings (29 × 0.70 ≈ 20.3 expected to root).
This is the minimum whose expected yield just meets your target, so it carries no safety margin — take 10-20% more if you want a reliable buffer against a poor batch.
Pots are then worked out from your cuttings-per-pot setting (default 3 per 9cm pot, a standard UK propagation method).
Frequently Asked Questions
Softwood cuttings (taken in spring/summer) typically root at 60-80%. Semi-ripe cuttings (late summer) around 50-70%. Hardwood cuttings (winter) are 40-60% but very easy.
Place 3-5 cuttings around the edge of a 9cm pot. They root better at the pot edge where drainage is best. Larger pots can hold more.
Softwood: April-June. Semi-ripe: July-September. Hardwood: October-February. Each type suits different plants.
Heated propagators speed up rooting significantly for softwood and semi-ripe cuttings. Bottom heat of 18-21°C is ideal. Hardwood cuttings do not need heat.
Softwood cuttings: 2-4 weeks. Semi-ripe: 4-8 weeks. Hardwood: 3-12 months. A gentle tug that meets resistance indicates roots have formed.
Yes. This calculator gives the minimum number whose expected yield just meets your target — at 70% success, 29 cuttings root about 20 plants on average, so a poor batch can leave you short. Take 10-20% more (a couple of extra cuttings) as a buffer against variable rooting, pest losses and the odd cutting that damps off.
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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.