How the numbers are calculated

We use two models. Intensive-bed density multiplies bed area by a practical plants-per-square-foot value drawn from cut-flower production. Presets exist for 6″ (3.5/sq ft), 8″ (2.8/sq ft), 9″ (1.63/sq ft), 12″ (1/sq ft), 18″ (0.5/sq ft).

When a spacing has no density preset, we fall back to square-grid geometry: floor(length ÷ spacing) × floor(width ÷ spacing). Row and two-row patterns count floor(row length ÷ spacing) across the number of rows. We would rather show honest geometry than invent a density.

Seeds to start apply a 10% buffer over plants needed to cover germination and transplant losses, then round up. Trays divide seeds by standard plug counts (72 and 128 cells) and round up — you can't sow a fraction of a cell.

All date math is deterministic and timezone-safe: we work in plain calendar dates so “28 days after April 25” is always May 23, wherever you are. Seed-start dates count back from your frost or transplant date by each crop's indoor-start offset.

Bloom and harvest estimates add a crop's days to maturity to your planting date. Succession cutoffs count back from first fall frost by days to maturity plus one interval, leaving room to actually harvest.

Plantometry starts from crop-specific planning defaults — spacing, timing, maturity, and support needs — drawn from established horticultural guidance. Every one of those defaults is editable: you can change spacing, timing, production assumptions, and bed dimensions to match your cultivar, climate, and growing system.

Where a value genuinely varies by variety or growing system, we leave it unset and ask you to supply it rather than inventing a number to fill the gap.

Cut-flower production often uses different spacing, succession, and bed-planning assumptions than ornamental garden design. Plantometry's cut-flower defaults are informed in part by the methods and planning frameworks taught by Floret Flowers, together with other horticultural references and crop-specific research.

These values are starting points, not rules. Plantometry keeps operational assumptions editable so growers can adapt the calculations to their cultivar, climate, bed system, and experience.

Some results are exact arithmetic: plant counts, seed quantities, tray totals, and calendar dates follow deterministic formulas and always give the same answer for the same inputs.

Others are planning estimates. Bloom and harvest timing depend on cultivar, weather, climate, and growing conditions, so we present them as informed starting points you should adjust — never as guarantees.