Article: Global Warming Has Arrived in Our Own Backyards

by Loretta Wallace

Being an avid gardener, I like to keep up with gardening news, tips and ideas from a variety of different sources. For the past few years, I been hearing on TV and radio gardening shows about gardeners in the northern states such as Minnesota and Michigan now being able to grow things they have never been able to grow before due to overall winter temperature increases.

For those of you who are not gardeners, the country is broken down into gardening "hardiness zones". What that means is that you should choose and grow plants and trees that can survive in your "zone". For example, Philadelphia has been traditionally categorized as zone 6 and when I decide I want to plant a tree, shrub or perennial plant, I need to do a little research into which plants will survive in my "zone", which basically means which plants can survive the typical temperature conditions during winter in my area. Some plants will die and never come back if they have to endure a temperature of 30 degrees, other plants can withstand colder temperatures below zero before dying.

Apparently from 1990 to 2006 it appears that the winter temperatures across the US has increased to the point that nationwide our gardening zones designations have had to be reevaluated and revised across the board. The new map shows that the entire northern half of Nebraska has been changed to a warmer hardiness zone. On the new hardiness map for Philadelphia, it is now considered a definite zone 7 which means the winter temperatures has increased enough in my city to allow me to grow things that previously only gardeners further south could grow. While this is an exciting development from a gardening point of view as we now have more plant options to choose from, it is a catastrophe from an environmental point of view. It is undeniable evidence in our own back yards that proves global warming is real and is here.

A case in point is my eucalyptus "tree" which is a native of Southeast Australia where the average winter temperature is quite different than that of Philadelphia. I bought a tiny 6 inch eucalyptus plant as a decorative ornamental accent plant for the summer months for a planter outside my front door. In my area it is expected that such a plant will not survive the winter and is considered an annual plant which you need to buy each year. Well about 2 years ago just before Halloween when I was disassembling my planter for the winter, I removed the small eucalyptus plant and instead of putting it in the compost pile, "just for the heck of it", dug a hole in a small patch of dirt in my mostly concrete back yard and planted the eucalyptus. To make a long story short, that 6 inch plant is now over 25 feet tall and a bona fide TREE. If you look online there is conflicting data about what zones eucalyptus can survive in and there are reports of success growing them in Oregon and other places here in the US, but whether my tree is a valid indicator or not, there are numerous other reports from across of the country from gardeners proving that the overall winter temperatures in our country have changed and it is affecting gardening and farming practices. Unfortunately, if this trend continues at it's current rate, I will someday soon be able to grow a tropical climate lemon tree in my backyard here in Philly.

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