- Overnight lows as important as daytime highs to fruit trees.
- Arkansas fruit trees in bloom.
Arkansas has seen its share of record-high temperatures in February and March, but warm daily low temperatures are prompting Arkansas’ fruit trees to bloom, said Dan Chapman, director of the University of Arkansas System Division of Agriculture Fruit Research Station.
Since March 2, record highs were set or tied at Little Rock, North Little Rock, Monticello, Hot Springs and Batesville. Record highs were tied or set on Feb. 23 and Feb. 29 at Little Rock.
“We’re starting to see some pink in some of our peach trees,” Chapman said the week of Feb. 27. “This might be a little early, but maybe a week at the most, on average. Here we have had some years that we’ve been finished blooming by this time. In other years, we’ve seen this at the end of March, which is a whole lot better. The earlier they are, the more likely we are to see some frost on them.”
Frost isn’t a small worry for fruit growers. In 2007, an Easter Day freeze that followed a very mild winter nearly obliterated Arkansas’ fruit crop, taking an estimated 80 percent of the grape crop. Total peach production in 2007 was only $13,000, down from the $3.97 million in 2006. And the threat of frost always lingers. In Little Rock, there is a 50/50 chance of the last freeze hitting March 22, with the last frost on April 4, according to the National Weather Service.
“Twenty-eight degrees seems to be the magic number,” Chapman said. “You can lose some of the blooms in the low 30s, but about 28 degrees, that seems to kill the flower buds.”
The blooms are most vulnerable to freeze or frost kill when the petals fall off, just leaving the young fruit. “Twenty-eight degrees can do a lot of damage there,” he said.
Cold is necessary for trees to bear fruit. Chapman said the fruit trees require some chilling before the warm weather comes in order to bloom.
“There are a lot of different theories about that.” Some say the low temperatures have to remain between 32 and 45 for a certain amount of hours. Some peaches only require 400 hours of chilling. Others require three times as much.
Having the right variety in the right place is key to having fruit. For example, trying to grow a peach that needs 1,200 hours of chilling in south Arkansas won’t work. “It doesn’t know to come out. It gets really sparse and doesn’t leaf out correctly.”
“That can be a problem for people buying fruit from big box stores that don’t get varieties specific for the region.”
For more information on fruit production, contact your county agent or visit www.uaex.edu.