American Farm Publications, Inc.
P.O. Box 2026
Easton, MD 21601
Bothered by global warming, changes in hardiness zone? Plant more plants (Editorial)
Many were quick to point out that changes in the USDA's plant hardiness zones show the impact of global warming, something gardeners have already noticed, they said. Hardiness zones, based on average low winter temperatures, are moving northward. This means that plants — and pests — that wouldn’t have survived through winter in some regions 20 years ago are now making it, and that could be good or bad.
“Changes in climate due to carbon pollution will create some enormous new challenges for gardeners,” said Patti Glick, senior climate change specialist with the National Wildlife Federation. “Global warming is changing the relationship between our garden plants and the climatic variables they face.”
A news release from NWF noted: "While some gardeners may welcome the opportunity to experiment with new plants, these shifting zones caused by climate change can be problematic. The country is seeing more weather and climate extremes that can be quite challenging for plants. Summertime heat and humidity have been increasing. Droughts are becoming more severe leaving plants more susceptible to disease. Heavy rainfall events are getting even heavier, increasing the likelihood of devastating floods. Gardeners may be able to grow some new plants, but some (of their) old favorites may have a harder time as summer temperatures increase and precipitation patterns change."
Warmer winters also open the door for harmful invasive species, pests and diseases. The northernmost range of kudzu, the “plant that ate the South,” has already moved to southeastern Nebraska and western Pennsylvania. Other plants moving into new areas include garlic mustard, purple loosestrife and Japanese honeysuckle.
NWF also pointed out that pests formerly kept in check by hard winter freezes are also moving north. For example, the range of the red imported fire ant (Solenopsis invicta) had historically been limited in the United States by cold temperatures and winterkill. Now scientists project that the range of this South American pest could expand northward by about 80 miles and grow in total area by 21 percent as climate change makes new areas suitable for their survival. Global warming also has unwanted pests like the black vine weevil, gypsy moth, bagworm and the mountain pine beetle on the move.
Glick's book, "The Gardener’s Guide to Global Warming: Challenges and Solutions," suggests steps gardeners can take to help solve the challenges posed by global warming, including:
• Reduce the use of gasoline-powered yard tools that put carbon pollution into the atmosphere.
• Remove invasive plants from the garden and choose an array of native alternatives.
• Reduce water consumption, which will improve the resiliency of your garden during droughts and heat waves, reduce energy consumed to transport water; and reduce runoff of fertilizer into waterways.
• Plant lots of native trees and native grasses to absorb carbon dioxide from the atmosphere and serve as long-term carbon storage.
Sounds like the opportunity for a new marketing strategy based on native and "water-wise" plants!