Gardeners Need to Understand Climate and Weather

Climate is the usual seasonal range of temperatures, types and amount of precipitation, wind, cloud cover, etc. Climate is weather over a long period of time, years or decades. Climate changes are relatively slow.

For gardeners, climate controls what type of plants can be grown. The length of the growing season is one important factor.

The growing season is the time of year between the last frost in the spring and the first frost of the fall. The growing season is the period of the year when no freezing weather occurs.

While it varies from year to year, the average growing season for a particular area determines what crops a farmer can grow. For example, farmers in Wisconsin do not attempt to grow cotton since their growing season is seldom long enough for the cotton plant to mature and produce a profitable crop. Growing seasons are short in cold climates, but are year round in tropical areas where no frosts occur, such as southern Florida.

Also important are the extremes of temperature. Plants have a limit as to how cold a temperature they can survive. Most annuals die if exposed to freezing weather. Perennials usually die back to the roots during winter, but even perennial plants will die if the freeze exceeds a limit specific to that type of plant. The more deeply the soil freezes, the more types of plants will die.

The US Department of Agriculture has published a map of Hardiness Zones.

Perennials are rated according to which zone they can survive from 1 to 12. One being the coldest.

Heat also matters. Some plants thrive in high temperatures, but plants native to cool regions will likely shrivel in hot weather.

Weather is the day-to-day or even minute-by-minute atmospheric conditions of temperature, air pressure, humidity, precipitation, wind, cloud cover, pollution, etc.

Most yards provide a variety of environments for growing plants. A southern exposure has sun all day. A northern exposure may get no direct sun at all. Eastern exposures tend to provide shelter from the hottest rays of the sun.

Trees, fences, houses, and other structures provide localized shade. These shady areas change in shape as the sun migrates through the day and through the seasons.

Structures, trees, and shrubs also change the wind flow. They will block wind from some areas and funnel it into others.

Houses and fences may partially block rainfall in some spots but concentrate precipitation in others. Down spouts from gutters may flood a spot during a rain.

A sloping landscape also affects plants. Soil on a slope drains more quickly, but moisture accumulates at the base. A south facing slope is warmer than a flat landscape. A north facing slope gets less sun and warms more slowly in the spring.

Trees and shrubs will compete strongly for nutrients in the soil as well as moisture. Their thick roots can out compete many garden plants.