USDA Zone 10b

Zone 10 · The Subtropics Proper

Average annual extreme minimum temperature: 35 to 40 °F (1.7°C to 4.4°C).

South Florida, the Rio Grande's mouth, coastal Southern California, Hawaiian uplands — 30 to 40°F winters that rarely freeze. Winter is the garden's high season; mango and avocado replace apple and peach.

By the numbers

Median season: Year-round
ZIPs tracked: 474

Medians across every ZIP we track in zone 10b, derived from NOAA 1991–2020 climate normals. Look up your own ZIP for local dates — within a zone, frost varies by weeks.

Where you'll find zone 10

South Florida from roughly Fort Myers and West Palm Beach southward (42% of Florida ZIPs in our data are zone 10), the southern tip of Texas at Corpus Christi and Harlingen (10a), coastal Southern California, and Hawai'i's cooler uplands.

Vegetables that earn their keep

The winter garden (UF South Florida calendar): broccoli, cabbage, cauliflower, collards, kale, lettuce, and tomatoes planted into the cool season, January–March for the last rounds
Warm-season crops April–September — but June–August is "too hot and wet for most fresh vegetable planting" (UF)
Salt-sensitive crops to keep off the immediate coast: beans, cucumbers, lettuce, tomatoes (UF)

Fruits & perennials that overwinter

Mango — mature trees withstand brief ~25°F with leaf/twig injury; blossoms and fruit are hurt below 40°F (UF)
Avocado — West Indian race tolerates 25–30°F, Guatemalan 24–28°F, Mexican 18–26°F mature (UF)
Citrus of every kind thrives (UF)
Only the very lowest-chill peaches (~100 hours: 'UFSun' types) reach this far south (UF)

Winter is the growing season

UF's South Florida gardening calendar inverts the national pattern completely: the productive months run October through May, the last cool-season plantings go in January–March, and June through August is the off-season — too hot and too wet for most vegetables. Summer's jobs are soil solarization (the heat becomes a tool for cooking weed seed and nematodes) and starting seedlings indoors for the October garden.

The orchard goes tropical

This is where the fruit list rewrites itself. Mango and avocado anchor home landscapes along both South Florida coasts — with cold tolerances now measured against rare radiative freezes rather than real winters (mature mangos take a brief 25°F with injury; avocado tolerance varies by race, 18–30°F). Citrus is fully at home. Temperate fruit is nearly gone: only UF's most extreme low-chill peaches (~100 hours) hold a foothold.

The hurricane factor

Gardening's biggest risk here arrives by forecast, not by frost. UF's hurricane-landscaping guidance: choose wind-resistant trees, thin canopies so wind passes through, secure containers and loose objects before storms — and respect storm surge, because saltwater flooding raises soil salinity that salt-sensitive vegetables (beans, cucumbers, lettuce, tomatoes) won't forgive. Irrigation water above 1,000 ppm salt kills many plants outright (UF).

Sand, nematodes, and no reset button

South Florida's sandy, low-organic soils need constant feeding, and the mild winters never knock pest and disease populations back (UF). Resistant varieties, heavy composting, and the summer solarization ritual are the standing defenses.

Plant guides, timed to your frost dates

Every guide gives its planting calendar relative to your last frost — the dates above (or your ZIP's) drop straight in.