Zone 10b: What Grows and How to Garden There
Frost is rare in zone 10b. Citrus of every kind, avocados and tropical ornamentals grow outdoors, and mangoes, papayas and bananas thrive in Florida's part of the zone. The challenge is the reverse of a cold-climate garden: too little winter chill for most apples, peaches and cherries, so only low-chill cultivars bear.
- Coldest winter night
- 35 to 40°F
- ZIP codes in the zone
- 474
Frost in zone 10b
In 97% of zone 10b'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. Use the planting calendar for your region: Southern California Coast, Southern California Inland Valleys, San Francisco Bay Area & Northern California Coast, South Florida, Central Florida.
What a zone 10b winter means
Frost is rare across nearly all of zone 10b. Cold-sensitive citrus, avocados and tropical plants grow outdoors year-round with little risk, and gardeners in South Florida add mangoes, papayas and bananas. The limit is winter chill: UC Cooperative Extension calls insufficient chilling probably the most limiting climate factor for apples, apricots, nectarines, peaches and sweet cherries along the California coast.
Where zone 10b is
Zone 10b includes Los Angeles, Long Beach, Torrance, Downey and the coastal plain of Orange County (Irvine, Santa Ana, Huntington Beach, Costa Mesa); San Diego and Chula Vista; Oxnard; and San Francisco. In Florida it covers St. Petersburg, Cape Coral, West Palm Beach and Coral Springs and much of southwest and southeast Florida north of Miami. Parts of the South Texas coast and a small upland area of Hawaii’s Big Island around Honokaa are also 10b.
Fruit
- Low-chill deciduous fruit: see the FAQ for apples. UF/IFAS explains that low-chill peaches such as ‘UFSun’ and ‘UFBest’ (about 100 chill units) were bred for central and south-central Florida.
- Citrus: all types, including limes and lemons.
- Avocado: ‘Hass’ and other Guatemalan types tolerate about 29°F, Mexican types about 25°F (UC ANR); young trees are most at risk in a cold night.
- Mango, papaya and banana: mango suits zones 10A-11 (UF/IFAS); papaya thrives at 70-90°F.
Perennials and bulbs
Perennial salvias bloom year-round unless frost knocks them back (UF/IFAS). Tropical and subtropical bulbs such as amaryllis, crinum, rain lilies and agapanthus naturalize (UF/IFAS). Spring bulbs that need winter cold do not repeat.
Special concerns
- Florida soils and nematodes: most Florida soils are sandy and low in organic matter, need more frequent watering, and host root-knot nematodes. UF/IFAS suggests cover crops such as sunn hemp and sorghum, rotation and solarization.
- Summer: large-fruited tomatoes stop setting fruit once nights average about 80°F; grow cherry types or wait for fall.
- Rare cold: protect young tropical trees with covers reaching the ground and water the soil the day before.
Where zone 10b is
States with zone 10b ZIP codes, the largest first: California, Florida, Texas, Hawaii.
Largest cities in zone 10b
Zone 10aZone 11aAll zones and the zone finder
Questions
Can I grow apples in coastal Southern California?
Yes, with low-chill cultivars. UC Cooperative Extension recommends cultivars needing under 300 chill hours on the coast and lists 'Anna', 'Beverly Hills', 'Dorsett Golden', 'Ein Shemer', 'Gordon' and 'Tropical Beauty'. It notes there are no low-chill sweet cherries.
What happens when a fruit tree doesn't get enough chill?
It leafs out late, blooms over a long period and drops buds, so it sets few if any flowers and little fruit (UC Cooperative Extension). Texas A&M adds that several seasons of too little chill can kill the tree.
When should I plant vegetables in zone 10b?
In South Florida, mainly from fall through spring. UF/IFAS says vegetables can be grown year-round with the right planting dates, but crops planted in late summer face hot-weather insects and diseases, and large-fruited tomatoes stop setting fruit in summer heat.