ZIP code & growing zone
How Heirloom finds your zone and frost dates, and how to change them.
Type your 5-digit ZIP into Location and press GO!. Heirloom looks up your USDA hardiness zone (2023 map) and fills in average frost dates for that zone.
You can also pick a zone from the Zone menu directly. Changing the zone redraws the whole timeline.
Zone frost dates are regional averages. Hills, lakes and cities can shift your yard by weeks. If you know your real dates, set custom frost dates.