Q. What are microclimates and why are they important in gardening? Gardeners throughout the U.S. should be familiar with the USDA plant hardiness zones which are based on minimum winter temperatures.

That's because mountains create their own microclimates—areas in which the climate differs from the prevailing climate. Take Kilimanjaro. This 19,340-foot volcano in Tanzania has microclimates ...

These areas with their small variations are called microclimates. Physical features such as water areas can have a cooling effect on the land. Trees can shade the land, also making it cooler.