About
Better planting starts with a plan
Plantometry is a set of free planting calculators for growers who want to know when to sow, how much to plant, how much space they need, and when to expect a harvest or bloom.
Most planting advice lives in scattered seed packets, forum threads, and half-remembered rules of thumb. Plantometry gathers the practical numbers growers actually use and turns them into answers you can act on: plant counts for a specific bed, a sowing date counted back from your frost, a succession schedule that respects the end of the season.
Every calculator is transparent. We show the formula, the assumptions, and how each number is derived — and we never invent data to fill a gap. When a crop's days to maturity genuinely varies by variety, we say so and ask you to supply it rather than guessing on your behalf.
The current database covers 105 of the most-searched cut flowers, vegetables, and herbs, with grower-referenced defaults for spacing, timing, and maturity. Every default is editable, because your conditions are not our defaults.
Start with a calculator
Curious how the math works? Read the methodology.