This is the second half of a story on Florida peaches. The first segment on Florida peaches ran Nov. 22.
Peaches need to “chill out”
To understand what makes a peach appropriate for growing in warmer climates, you need to understand that for peach blooms to set and grow properly, they require a certain number of “chill units” — hours when temperatures measure from 32 degrees to about 45 degrees.
Over the course of their growing season, Georgia peaches require 350 to 850 chill units. Jose Chaparro, an associate professor in the Fruit Tree Breeding and Genetics Program at the University of Florida (UF) in Gainesville, and his predecessors at UF have been working to create low-chill varieties that require only about 150 chill hours, or units, so they can be grown in climates like those in Central and Southern Florida.
As for traits, he’s breeding for sweetness, moderate to low acidity, larger size, firmness of flesh, and fruit that doesn’t oxidize or turn brown when cut.
The new varieties Chaparro has developed work so well that, today, they are being grown not only in the United States but also around the world — wherever temperatures require mid- to low-chill varieties — including Australia, Spain, Morocco and South Africa.
Even with dependable varieties, though, caring for peaches in warm climates is difficult. “Peaches grown in the tropics are a high-maintenance crop. You have to be vigilant, and the labor required can make growing expensive,” says Mercy Olmstead, an assistant professor and extension specialist in the Horticultural Sciences Department at UF in Gainesville.
Not easy to keep peaches “happy”
Here in Florida, John Sizemore, who co-owns Sizemore Farms in Polk County, is discovering just what it takes to be a peach farmer. “It’s a lot more intensive crop than citrus,” says Sizemore, who has had experience with both. He started raising peaches in 2012.
“Not that peaches are more difficult, but they do require more management and man-hours, as well as a significant amount of handling.”
When it comes to growing the trees, what makes Florida peaches different from those in orchards farther north is that the subtropical trees grow year-round. That means they need to be forced into dormancy during the winter months, and they need regular pruning as they continue to grow.
Sizemore sprays his trees in November with zinc oxide to force the trees to lose their leaves and become dormant. By December, before the trees start growing leaves, he prunes them for structure.
By the first two weeks of January, as the trees continue to experience chilly weather, buds begin to swell and bloom. “By then, the foliage is growing, and we have to thin out the blooms by hand to assure the fruit will grow as large as possible,” Sizemore explains.
As the blooms develop over a period of weeks, the initial thinning is followed by another that assures there is only one bloom for every six to eight inches.
Harvesting peaches time-consuming
Then it’s only about 85 days from bloom to the mature fruit that’s ready to harvest by hand. Because the trees have taken a week or two to finish blooming, not all the fruit ripens at one time. That means multiple passes through the orchard to pick the fruit as it turns yellow.
Then there’s the need for another pruning in late fall or early winter — to give the tree shape and to keep it from getting too tall for efficient harvest.
Due to all the pruning, thinning and harvesting, peach growers need to hire a good deal of skilled staff, and that can be expensive. And, of course, if there aren’t enough chill days, that too takes its toll on crop yields.
But growers believe that with every new and improved variety that hits the market, and with more consumers trying — and being impressed with — this tree-ripened fruit, Florida peaches will become an important crop.
“I would tell others who want to get into Florida peach-growing that they need to do their research before they plant. There is a lot to learn,” Sizemore says.