Zone 11b: What Grows and How to Garden There
Zone 11b, in the Florida Keys and a few Hawaii communities, never sees frost in a normal winter. Tropical fruit such as mango, papaya, banana and Key lime grows outdoors, but plants that need winter chill do not, and the garden calendar follows the dry season, heat and rain instead of frost.
- Coldest winter night
- 45 to 50°F
- ZIP codes in the zone
- 11
Frost in zone 11b
In 100% of zone 11b's ZIP codes with weather records, a 32°F night happens in fewer than half of years, so frost dates do not organize the gardening year. Cool-season vegetables grow from fall through spring, and heat, not frost, ends the season for many crops.
What a zone 11b winter means
Zone 11b’s coldest winter nights stay far above freezing. That makes it one of the few places in the United States where cold-tender tropical fruit and ornamentals grow without any winter protection. The flip side is the lack of winter chill: fruit that needs a cold dormancy, such as apples, peaches, cherries and blueberries, will not fruit, and spring bulbs such as tulips do not rebloom. Even here, UF/IFAS notes that tropical plants and some palms can be injured by chilly nights well above freezing.
Where zone 11b is
In Florida, zone 11b is the Keys, from Key Largo and Islamorada to Marathon and Key West. In Hawaii it includes a few Big Island and Maui communities such as Ocean View, Mountain View and Hana.
Fruit
- Mango: a natural fit for the zone (UF/IFAS).
- Key lime: very cold-sensitive, best in the warmest parts of Florida.
- Papaya: fast-growing and productive at 70-90°F; damaged below about 31°F, which is not a concern in a normal 11b winter.
- Banana: grows well; in South Florida watch for nematodes, Fusarium wilt and sigatoka (UF/IFAS).
Shrubs, perennials and bulbs
Tropical and subtropical bulbs such as amaryllis, crinum, rain lilies and cannas grow outdoors permanently. Plant sterile lantana cultivars rather than common lantana, which UF/IFAS lists as invasive in Florida.
Special concerns
- Season: grow most vegetables in the dry, cooler months; summer is the off-season for tomatoes and many other crops.
- Soil: most Florida soils are sandy and low in organic matter (UF/IFAS); add compost and water more often. Root-knot nematodes thrive in warm soil, so rotate crops and solarize.
- Wind: in Hawaii, the University of Hawaii notes that the north and east sides of a house get the most wind, and a sorghum-sudangrass windbreak can reach 6 feet in about 40 days.
Where zone 11b is
States with zone 11b ZIP codes, the largest first: Florida, Hawaii.
Zone 11aZone 12aAll zones and the zone finder
Questions
What fruit trees grow in the Florida Keys?
Tropical fruit that needs no chill. UF/IFAS lists mango for zones 10A-11 and describes Key lime as very cold-sensitive, suited to the warmest parts of Florida. Papaya grows best at 70-90°F. Temperate fruit such as apples and peaches, which need winter chill, will not bear.
When should I plant vegetables in zone 11b?
In the cooler, drier months from fall into spring. UF/IFAS says Florida can grow vegetables year-round with the right dates, but summer heat stops large tomatoes from setting fruit once nights average about 80°F, and late-summer plantings face heavy pests.
Do I need a hardiness zone at all in zone 11b?
Mainly to judge cold-sensitive tropicals. USDA added zones 12 and 13 so gardeners can compare the cold tolerance of tropical plants, but in zone 11b heat, salt, wind and rainfall usually limit plants more than cold does.