May means very different things in zone 4 and zone 9 — pick your zone below. Not sure which zone you're in? The frost date lookup tells you in one ZIP code.
| Zone | Start indoors | Plant outside | |
|---|---|---|---|
| Zone 1 | 22 crops | 22 crops | Interior and Arctic Alaska |
| Zone 2 | 15 crops | 30 crops | Central Alaska (Fairbanks area), highest Rockies |
| Zone 3 | nothing yet | 46 crops | Northern Minnesota and North Dakota, northern Maine, high mountain valleys |
| Zone 4 | nothing yet | 33 crops | Northern Plains, northern New England, much of Montana and Wyoming |
| Zone 5 | nothing yet | 24 crops | Southern New England, Great Lakes, Iowa, Nebraska, Colorado Front Range |
| Zone 6 | nothing yet | 7 crops | Mid-Atlantic, Ohio Valley, Kansas, inland Pacific Northwest |
| Zone 7 | nothing yet | nothing yet | Upper South (Virginia, Tennessee, Oklahoma), New Mexico highlands |
| Zone 8 | nothing yet | nothing yet | Deep South, central Texas, coastal Pacific Northwest |
| Zone 9 | nothing yet | nothing yet | Gulf Coast, central Florida, central California, Phoenix and Tucson |
| Zone 10 | nothing yet | nothing yet | South Florida, coastal Southern California, low desert |
| Zone 11 | — | heat-driven calendar | Miami and the Keys, Hawaiʻi coasts |
| Zone 12 | — | heat-driven calendar | Hawaiʻi lowlands, Puerto Rico |
| Zone 13 | — | heat-driven calendar | Warmest tropical coasts and territories |
Every count above comes from the same arithmetic: each crop's planting windows are counted off the zone's typical last and first frost, then checked against May. Cold zones run weeks behind warm ones with the same to-do list — which is why "what to plant in May" has thirteen different answers. Zone pages carry the full crop-by-crop windows, and the planting calendar localizes them to your own frost dates.