Introduction
A plant spacing calculator is more than a cute garden gadget. It is a compact decision engine for translating biological needs into geometry you can lay out on soil, raised beds, containers, or rows. When you place plants at the right distance you are really optimizing several competing forces at once: light interception, airflow and disease suppression, root-zone access to water and nutrients, pest scouting visibility, harvest ergonomics, and even wheelbarrow clearance. Poor spacing compounds costs through weak plants, mildew, lodging, and yield penalties; over‑wide spacing wastes land and water, slows canopy closure, and invites weeds. This guide explains the math behind spacing, shows how to design a dependable calculator, and provides a tested crop library so you can go from idea to field‑ready plan without guesswork.
We will start with the essentials—how to compute the number of plants a given area can support in rectangular rows or triangular (hexagonal) patterns—and then step into real‑world constraints: bed widths, path widths, modular trays, transplant plug sizes, interplanting, succession planting, and pruning systems. You will learn how to convert between plants per square foot, plants per square meter, and populations per acre or hectare; how to compute area per plant and population density; and how to incorporate edge effects that make small beds and pots behave differently than big fields. If you are a home gardener, market grower, or landscape designer, the same principles apply; the calculator just lets you toggle assumptions instead of re‑deriving the math each time.
