Lychee and longan — Sebastian, Florida

For a Sebastian yard, lychee and longan are close cousins with nearly the same cold limits and flowering needs, but longan is a little less cold tolerant, bears sooner from air layers and has fewer disease problems.

The two University of Florida factsheets read almost as a pair. UF/IFAS EDIS MG049 states that longan is slightly less cold tolerant than lychee (UF/IFAS EDIS MG049), and EDIS MG051 says lychee has more cold tolerance than mango but less than sweet orange (UF/IFAS EDIS MG051). Both are large, dense, evergreen trees, both bloom in late winter and both fruit in summer. The comparison below sets out the Sebastian-relevant numbers.

Salt is a separate limit. UF/IFAS Gardening Solutions says lychee grows in USDA Hardiness Zones 10A through 11, is moderately tolerant of flooding and drought, but cannot survive in salty environments (UF/IFAS Gardening Solutions). For Sebastian, that points a lychee away from salt-exposed ground along Indian River Drive and toward inland lots in the Sebastian Highlands or west of US 1.

Lychee and longan need a cool, dry, frost-free winter to set flowers, and a warm wet winter or a winter freeze in Sebastian can each cost a crop, which is why both are known for erratic bearing.

The flowering trigger is a cool, dry spell. MG051 says the best lychee climates have a dry, cold but nonfreezing winter lasting 3 to 5 months, a warm spring during flowering and a hot, humid summer (UF/IFAS EDIS MG051). MG049 says longans produce more reliably where fall and winter bring nonfreezing temperatures of 59 degrees F or less and a dry period from October to February, and that warm, rainy winters favor leaves over flowers (UF/IFAS EDIS MG049). A Treasure Coast winter can deliver that pattern in one year and miss it in the next.

The result shows up in any Sebastian harvest record. MG051 calls unreliable bearing the major constraint to lychee production: mature 'Brewster' trees may bear 200 to 300 lb in a good year, but most bear a good crop only about 1 year out of 3 or 4. Longans also bear erratically, with some years producing little or no fruit, and mature trees range from 50 to over 500 lb, according to MG049.

Growers can nudge the odds. MG051 says nitrogen fertilizer should be avoided on bearing lychees from August until early spring, because it pushes new leaves at the expense of flowers, and that mild drought stress in September or October may enhance flowering. In Indian River County, the summer fertilizer blackout from June 1 to September 30 exempts trees grown for their edible fruit and applies in unincorporated areas (Indian River County), and Section 50-5 of the Sebastian city code carries the same edible-fruit exemption inside city limits (City of Sebastian), so the UF/IFAS timing, not the fertilizer blackout, is the limit that matters for a Sebastian lychee.

Sebastian growers usually choose 'Mauritius' for the most regular lychee crop, 'Brewster' or 'Hak Ip' for anthracnose resistance, and 'Kohala' as the standard longan.

UF/IFAS rates the lychee cultivars sold to Sebastian growers by bearing habit and anthracnose. In MG051, 'Mauritius' is the major commercial cultivar and bears more regularly than 'Brewster', the second most grown, though 'Mauritius' fruit is more susceptible to anthracnose (UF/IFAS EDIS MG051). Gardening Solutions adds 'Kwai May Pink', 'Emperor', 'Hak Ip' and 'Sweet Cliff' as recommended cultivars and notes that while single trees still fruit, planting more than one cultivar can increase production (UF/IFAS Gardening Solutions).

Longan choice is simpler. MG049 states that 99 percent of Florida longan acreage is planted with 'Kohala' and that nothing superior to it has been identified, while the Thai cultivar 'Diamond River' is reported to fruit every year but has only fair fruit and limbs very susceptible to breakage (UF/IFAS EDIS MG049), a real drawback in a Sebastian hurricane season. Air-layered lychee, longan and other fruit trees for Sebastian yards appear among the fruit trees on Digital Towns Market. Digital Towns Market is our marketplace.

The lychee erinose mite is a microscopic pest that raises hairy galls on lychee leaves and can wipe out most of a crop, and Florida stopped trying to eradicate it statewide in November 2022, so Sebastian growers now manage it themselves.

For Sebastian lychee owners, the mite is the pest to know. FDACS describes it as a pest of lychee trees that causes erineum galls, hairy abnormal growths, on the leaves, and says an unchecked infestation can severely damage the tree, fruit and flowers (FDACS). Gardening Solutions calls it the most severe pest of lychee and says an infestation can cause an 80 percent reduction in fruit production (UF/IFAS Gardening Solutions).

The state has stepped back from Indian River County and the rest of Florida. FDACS eradicated the mite in Sarasota County in 1957 and in Miami-Dade County in 1993, but on November 1, 2022 suspended eradication statewide because of lack of funding and the pest's widespread distribution, and its Division of Plant Industry no longer provides survey or treatment. It still identifies samples, and it points homeowners to UF/IFAS dooryard recommendations. Last verified: October 10, 2026, on the FDACS website.

Other pests are more ordinary. MG051 lists moths on the flower panicles, scales, Diaprepes and citrus root weevils and nematodes, plus anthracnose on fruit and mushroom root rot, which occasionally kills lychees, often on land where live oaks grew before, a point worth checking on Sebastian Highlands lots cleared of oaks. Longan has no major disease problems at present, with lychee webworm and scales as its common pests, per MG049. Master Gardener volunteers from UF/IFAS Extension Indian River County help diagnose such problems, including at their weekly Sebastian clinic in the north county library (UF/IFAS Extension).

In Sebastian, both trees start best as air layers planted in full sun on well drained ground well away from the house, are pruned right after harvest, and are picked only when fully sweet because neither ripens after picking.

Air layers are the standard for Sebastian plantings. MG051 says lychee does not come true from seed, seedlings may take 10 or more years to bear, and air layering is the most common method in Florida, with air-layered or grafted trees bearing in 3 to 5 years (UF/IFAS EDIS MG051). MG049 says longan air layers are best made from April through August and root in 10 to 12 weeks.

Soil and water decide survival. On a Sebastian lot, MG051 says lychee grows best in acid sands with moderate organic matter, and that sandy soils low in organic matter are suitable if enough fertilizer is supplied. Longan is not tolerant of excessively wet soil, and young longans may decline and die after 5 to 10 days of flooding in hot weather (UF/IFAS EDIS MG049), so low Sebastian yards that hold water after August storms need a mound.

Pruning follows the harvest. MG051 advises pruning lychees immediately after harvest so new shoots mature before winter, and cutting tops back to 10 to 15 ft after several years of production. Gardening Solutions suggests keeping longans 10 to 15 ft high, says the fruit will not ripen further once picked, and notes that bagged longans keep five to seven days in the refrigerator (UF/IFAS Gardening Solutions). Timing questions for Sebastian trees can go to UF/IFAS Extension Indian River County, 7961 58th Avenue, Vero Beach, (772) 226-4330 (UF/IFAS Extension Indian River County).