Low-Chill Peaches — Sebastian, Florida

Yes, but the lowest-chill University of Florida peaches are the safest match for Sebastian, where the nearest UF/IFAS chill station logged fewer than 150 chill units in 8 of 12 winters.

UF/IFAS EDIS publication MG374 says the University of Florida has developed high quality, low-chilling, early-maturing peach and nectarine cultivars that can be grown from the panhandle to as far south as Immokalee, and that chill units decrease as one moves south in the state (UF/IFAS EDIS MG374). Low-chill cultivars need 100 to 250 chill units, against 300 to 525 for the moderate-chill types bred for north Florida and Georgia. On the Fort Pierce record below, Sebastian is a match only for the bottom of the low-chill list.

Gardening Solutions puts the home-garden limit a little differently: home gardeners as far south as Fort Myers may have luck growing peaches, and trees planted in spring can be expected to begin fruiting the following spring (UF/IFAS Gardening Solutions). It adds that a well-tended home peach generally produces fruit for 8 to 10 years, so a Sebastian peach is a planting with a clear end date rather than a permanent tree.

Peaches and nectarines are the same species, Prunus persica, and MG374 notes that nectarines differ only in lacking peach fuzz. The practical difference in Sebastian is chill: UF's nectarines need more of it, as the cultivar table below shows.

The nearest station in the UF/IFAS chill table, Fort Pierce, logged between 49 and 253 chill units a winter from 2000-01 through 2011-12, with 4 of those 12 winters below 100 (UF/IFAS EDIS MG374).

MG374 counts chill units as hours between 32°F and 45°F from November 1 to February 15, using the Florida Automated Weather Network. Gardening Solutions describes chill hours the same way, as nighttime temperatures between 32 and 45 degrees Fahrenheit (UF/IFAS Gardening Solutions, peaches), and says low-chill peaches, plums and nectarines need 100 to 525 chilling hours per year (UF/IFAS Gardening Solutions). Fort Pierce is the Table 2 station closest to Sebastian, so its numbers are a close, though not exact, stand-in for a Sebastian yard.

Counting from the table, Fort Pierce reached 100 chill units in 8 of the 12 winters and 150 in only 4 (2000-01, 2002-03, 2009-10 and 2010-11). That is the core reason a 100-unit cultivar is the safer pick for Sebastian than a 150-unit one, and why a 200-unit or higher cultivar is a gamble on the Treasure Coast.

Temperature records from Vero Beach point the same way. NWS Melbourne's 1981-2010 normals give Vero Beach a January mean temperature of 62.1°F (NWS Melbourne), and its cool-season table shows a median of 221 days a year with no reading below 50°F (NWS Melbourne).

UFSun and UFBest, each rated at 100 chill units, are the best fit for Sebastian, followed by the 150-unit group that includes Flordaprince, TropicBeauty and Flordaglo, according to the UF/IFAS cultivar table (UF/IFAS EDIS MG374).

MG374 gives each cultivar a January mean temperature and says areas with that January mean or a lower one provide sufficient chilling. Set against the Vero Beach January mean of 62.1°F, every cultivar in the first six rows below clears the bar, UFGold at 62.0°F falls 0.1 degree short of it, and the Sunbest nectarine at 61.0°F needs a cooler January than Indian River County normally has.

Flordaprince, spelled that way by UF/IFAS, was released by UF in 1982, has been a standard low-chill peach worldwide and is one of the earliest ripening; its fruit are large, firm and yellow with semi-clingstone pits. Its weak point is bacterial spot, where it scores 4 of 10 for resistance. TropicBeauty, released by UF and Texas A&M in 1989, is non-patented, which matters to home buyers because Gardening Solutions notes that patented varieties are harder for homeowners to buy.

UFBest was released in 2012 and produces heavy annual crops of large fruit, while UFSun, released in 2004, bears heavy annual crops of medium fruit that ripen with Flordaprince. One caution from MG374 applies directly to Sebastian: UFBeauty cropping has been unreliable in south Florida when night temperatures during bloom stay above 57°F, so poor crops from warm bloom-season nights are documented, not hypothetical.

A Sebastian peach starts as a grafted tree on nematode-resistant rootstock, (UF/IFAS EDIS MG374), cut back to a bare stem at planting and then pruned twice a year into an open vase (UF/IFAS Gardening Solutions).

MG374 explains that all stone fruit grown in Florida is grafted because of the peach root-knot nematode, and that Flordaguard is the nematode-resistant rootstock recommended for both commercial and dooryard trees; its red leaves make root suckers easy to spot in the first two to three years. In Sebastian, the rootstock label is as important as the variety name.

Gardening Solutions describes planting a new tree with its side branches and part of the top removed so that it looks like a stick, then pruning twice a year: in winter for structure and in summer, after harvest, to let light in, always keeping the vase shape (UF/IFAS Gardening Solutions). It warns that Florida's frequent summer rain favors peach rust, that a tree defoliated by disease can bloom at the wrong time, and that squirrels and raccoons go after ripening fruit, which is why netting goes on as the fruit colors. Fruit trees for Sebastian yards appear among the fruit trees on Digital Towns Market, and garden supplies among the grow supplies on Digital Towns Market. Digital Towns Market is our marketplace.

Fertilizer rules depend on the address. Inside Sebastian city limits, the city's Florida Landscaping page lists a City Fertilizer Ordinance and a list of ordinance compliant fertilizers (City of Sebastian). Indian River County's ordinance, which the county says applies in the unincorporated areas, bars fertilizer between June 1 and September 30 and lists trees grown for their edible fruit among its exemptions (Indian River County).

Sebastian growers can bring a sick leaf or a variety question to the UF/IFAS Extension Indian River County Master Gardener plant clinic, held Wednesdays from 10:00am to 12:00pm at the North IRC Library, 1001 Sebastian Blvd. (CR512), or on weekdays at the extension office at 7961 58th Avenue in Vero Beach (UF/IFAS Extension Indian River County).