Ways to use local climates for better gardens

To grow a successful garden, you need to understand the climate, light and moisture conditions in your area. Here's how to make the most of your local weather and climate:

• Your best tool for identifying such plants is the Hardiness Zones Map (also called the Temperature Zone Map). It divides Canada and the United States into 11 zones.
• Most Canadian nurseries and mail-order companies have adopted the USDA map as a standard reference.
• Each zone is based on an average minimum temperature, which is an index of the local winter's severity. This temperature is the crucial factor in determining whether a plant will survive in a given region.
• Most plant descriptions indicate the zones in which a specific plant will thrive. Or a plant may be described as "hardy to zone 6," which means that the plant can generally withstand temperatures down to -18°C and -23°C.

• Plant hardiness can also be influenced by certain local conditions, like elevation.
• Because water collects heat from the sun, a garden near a pond will be both warmer in winter and cooler in summer than a garden just down the road.
• In summer, a garden near a pond will also benefit from the humidity contributed by nearby water.
• Within any garden, there are micro-climates — spots that are colder and warmer, wetter and drier, or sunnier and shadier than others.
• Micro-climates may force an adjustment in your use of the Hardiness Zone Map.
• If you have further questions about plant hardiness in your area, contact your local garden centre.

Here are some specific strategies for using your garden's micro-climates to best advantage:

• Put plants that are only marginally cold-hardy to the south of a building or hedge.
• Save the most cold-hardy plants for significantly low-lying areas, places where cold air and frost settle.
• Plant fruit trees on the north or east side of a slope or the house to prevent premature warming and blooming in early spring.
• Place moisture-loving plants near the bottom of downspouts or low-lying areas of your yard that collect water.
• Plants that like hot, dry conditions thrive by sunny driveways and walks.
• Plants described as shade-tolerant usually prefer afternoon rather than morning shade.
• Cut strong winds by planting a windbreak of trees or shrubs on the north or west side of the house. It can reduce chill winds by almost half.

A plant that's well suited to its surroundings will flourish with a minimum of help, while a plant transplanted to an inhospitable site will struggle no matter how much care you give it. Knowing your climate will help you pick plants that will thrive for a more beautiful garden.