Take Your Zone Into Consideration When Planning Your Plantings and Landscapes

Today, we added the USDA 2012 Plant Hardiness Zone Map under our Resource tab for Plant selection. It is important that you know in which zone you live to grow any plants in Colorado. Use this tool and learn about your zone.

The USDA’s zones are based on the average low winter temperature for an area.  In Colorado, our zones range from the cold Zone 3a (-40 to -35 degrees F. ave. low winter temp) to our warmest Zone 7a (0 to 5 degrees F. ave. low winter temp).  Across the United States, many areas have gone up to be one-half zone warmer.  But USDA cautions this is often less about global warming than it is about more accurate monitoring of temperature data.  And in mountain areas, because we now have better data, many areas have been re-classified to a colder zone.

Even if your area has moved up from 5b to warmer 6a, you need to know that any given year, the low temp could still bottom out below the average noted in the zone.  So if you start planting 6a plants, put them in protected areas and know that in extremely cold years, there could be winter die back.

We need to pay attention to our zones because they relate to winter hardiness–one of the most critical factors for ongoing plant survival.  Still, bear in mind that zone shifts don’t mean that scorching heat, high winds, poor soils, lack of water or an occasional extremely cold winter will go away.  All of Colorado’s challenging growing conditions make up our bottom line.

Success in the garden means checking seed packets and nursery catalogs to make sure plants you buy grow in your zone.  And, planting in the right exposure, using soil amendments and grouping plants based on similar water requirements are still the name of the game.

We thank the ALCC for this information on zones.