USDA Hardiness Zone 13 Planting Guide
Zone 13 covers locations where the average annual extreme minimum winter temperature ranges from 60 to 70 degrees Fahrenheit. This page covers both subzones: zone 13a (60 to 65 degrees F) and zone 13b (65 to 70 degrees F).
Zone 13 Overview
Zone 13, the warmest in the USDA system, covers equatorial lowlands where minimum temperatures stay between 60 and 70 degrees Fahrenheit year-round. Within the US context, this zone applies to the warmest microclimates in Hawaii and some Pacific territories. Temperature variation between seasons is negligible, and gardening is a continuous year-round activity with no seasonal dormancy period for any plants. Rainfall patterns and day length, rather than temperature, drive the garden calendar. Zone 13 represents the ultimate frost-free growing environment.
Zone 13 Temperature Ranges
| Subzone | Min Temp (°F) | Max Temp (°F) | Description |
|---|---|---|---|
| 13a | 60°F | 65°F | Equatorial lowlands; perpetual summer conditions |
| 13b | 65°F | 70°F | True tropics; no seasonal temperature variation |
Plants for Zone 13
Zone 13 supports the complete range of equatorial and tropical species. Ultra-tropical plants that struggle even in zone 11 or 12 thrive in these consistently warm conditions. Tropical hardwoods, rainforest species, and the most temperature-sensitive tropical fruits all find a home in zone 13. Plant selection is limited only by soil, water, and light conditions rather than temperature.
Vegetable Gardening in Zone 13
Vegetable gardening in zone 13 focuses exclusively on tropical crops adapted to equatorial conditions. Heat-adapted varieties of common vegetables may produce, but traditional temperate crops like broccoli, peas, and lettuce are not feasible at zone 13 temperatures. Root crops, tropical greens, heat-tolerant herbs, and equatorial fruiting plants provide the dietary base.
Frost Protection & Season Tips for Zone 13
Temperature protection is entirely irrelevant in zone 13. All gardening challenges relate to managing high rainfall, tropical storm damage, soil fertility maintenance in conditions that rapidly decompose organic matter, and controlling tropical pest and disease populations that thrive in perpetual warmth and moisture.