One of the topics I mentioned last week was Plant Hardiness Zones. 

This is something that you should familiarize yourself with if you plan to purchase plants.  It can be beyond frustrating to pick out a plant, take the time to plant it, only to have it freeze and die over its first winter.    Understanding and utilizing the USDA Plant Hardiness Zone Map is a simple and effective way to begin protecting your investment.

The original map was created by the combined efforts of the U.S. National Arboretum, the American Horticultural Society and horticultural scientists throughout the United States, and was first published by the USDA in 1960.  Revisions were made and the map was republished in 1965, then again in 1990.  The information it provides is based on the lowest average temperatures that can be expected in the United States, Canada and Mexico.  The map is divided into 11 different zones to represent the winter hardiness of both landscape and agricultural plants.  Zones 2 through 10 are subdivided into light and dark-colored sections, with the light representing the colder section of each zone.  This map provides a great amount of detail considering the vast amount of data it is based upon.  Many factors influence the average minimum temperature, including the expansion of urban areas, and may not be reflected by the current map, so use it as a guideline only.  The area we live in is considered Zone 6a and 6b, depending on where you live. Based on a minimum average temperature of -5 to -10 degrees for 6a, and -5 to 0 degrees for 6b, you should use plants that are known to grow in a zone range that includes our area.

All plants have a minimum temperature they can tolerate before death occurs. It is important to remember though that where the plant is growing greatly affects its temperature tolerance.  A plant growing in a container above the ground is much more susceptible to freezing temperatures as well as heat than a plant that whose root system is in the ground.  To take it one step further, a plant with a properly mulched and hydrated root system can survive much colder temperatures than a dry plant, or one that has no mulch to insulate it.  A plant growing on the south side of a building or one that is somewhat protected by a canopy of trees or the overhang of a building will react differently to freezing temperatures than one growing with a northern exposure.  It is a combination of these and other factors that can mean survival or death for a plant, and all of the possibilities should be considered if you are thinking of using a plant that is not listed for your zone.

Landscaping can be quite an investment, not only financially but also in the time and effort it takes to make it happen.  Take the time to learn as much as you can before you begin in order to protect your investment.