What we do
Most planting advice gives one date for the whole country. But garlic in Minnesota and garlic in Florida go in the ground two months apart, and tulips in South Carolina need a spell in the refrigerator first. PlantByZone gives the answer for each USDA hardiness zone, side by side, so you can find yours.
Every guide has a planting calendar by zone, the depths and spacings to use, and to-scale drawings, and the calculators turn your beds into bags and cubic yards.
Where the numbers come from
Planting dates come from university extension services, the public garden advice of each state’s land-grant university, because each one knows its own climate. Hardiness zones come from the 2023 USDA Plant Hardiness Zone Map. We name the source next to every date, and list the pages we used at the end of each guide. How we source our dates explains the method.
Found a mistake?
If a date doesn’t match your county extension office, or a number looks wrong, tell us. We check it against the source and fix the page.