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Protect Plants in Shifting Zones07-21-08 | News

Protect Plants in Shifting Zones

The differences are noticeable in the hardiness zone changes between 1990 and 2006. The Arbor Day Foundation has recently completed an extensive updating of U.S. Hardiness Zones based upon data from 5,000 National Climatic Data Center cooperative stations across the continental United States.
Photo Credit: Arbor Day Foundation

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Although global warming is much in the news these days, the planting zones have been shifting both up and down, depending on the location. Most areas are getting warmer, however sometimes they are unexpectedly colder. Often there are unexpected cold snaps that can ruin crops, kill plants and cause definite problems in the landscape.

A spray developed by Miami (Ohio) University researchers, which is not yet commercially available, can improve plants’ cold tolerance between 2.2 and 9.4 degrees Fahrenheit, depending upon the species. Research results indicate the spray, which the developers have named Freeze-Pruf, is effective on a variety of plants, including palms, tropical houseplants, bananas, citrus plants and flowers. Commercial growers, including those growing edible bananas in south Alabama, would benefit from the longer growing season that a more cold tolerant plant would provide.

This spring's unseasonably warm weather in late March and early April encouraged many trees and shrubs to leaf out earlier than normal. Newly emerged growth was then very susceptible to the freezing temperatures that followed in late April and May.
Photo Credit: Iowa State University

“It moves your temperature zone about 200 miles, so it’s highly significant,” said Dr. David Francko who wrote “Palms Won’t Grow Here and Other Myths.” He called cold tolerance products “one of the holy grails of horticulture.” Francko, who developed the spray along with Kenneth Wilson, Quinn Li and Alejandra Equiza, envisions the spray also appealing to gardeners and nursery owners looking to protect trees, shrubs, flowers and ornamentals from a late frost. A patent application on the product, a novel mixture that combines five ingredients in a water-based spray formula, was filed earlier this year. The inventors are working with The University of Alabama’s Office for Technology Transfer on the possibility of licensing the product to a company for commercial production or, alternatively, forming a UA spin-off venture to commercialize the technology.

“Each ingredient has a different function, but when you put them all together you get an effect that is larger than any single component, alone,” Francko said. “It’s non-toxic, it’s cheap, and the idea is to apply it once per season.” Each of the ingredients in Freeze-Pruf is already used, for other reasons, in various foods or in food production.

Existing sprays typically protect plants in weather only as low as the mid to upper 20s Fahrenheit. “Our spray works all the way down to below zero Fahrenheit, depending on the plant you’re working on,” says Franko. “It protects both the foliage and the flower.” The spray is already cost effective and researchers are exploring possible ways to perfect it so even smaller quantities of spray would bring similar results.

Adapted from materials provided by University of Alabama.

Source: ScienceDaily.com