Deb Babcock's gardening column appears Thursdays in Steamboat Today.
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Instead of holiday shopping catalogues stuffing our mailboxes, gardeners now are receiving catalogues of the new offerings from garden centers and mail-order nurseries for 2009. Eye candy. And, wow, it's so easy to satisfy your garden sweet tooth.
It's tempting to just look at the beautiful pictures of flowers, fruit, vegetables and trees in the catalogues and order away for colorful and interesting plants to fill in borders, bare spots and little garden niches needing something spectacular.
But, don't give in to temptation until you've checked out the ability of the plant to handle the cold temperatures during our winters here in Steamboat Springs, as well as the intense heat during our summers.
There are two reliable indicators you should look for in plants you want to grow here. One is the U.S. Department of Agriculture cold hardiness zone, and the other is the heat zone developed by the American Horticultural Society.
The USDA cold hardiness zone map was developed by gathering data from 7,000 weather stations throughout the country. For most of Steamboat, we are considered zone 4, meaning that the annual average lowest temperature ranges between -30 and -20 degrees F. Some local gardens experience even colder low temperatures and would be considered zone 3 (-40 to -30 degrees F), while some areas never get lower than -20 degrees F (zone 5).
The AHS heat zone indicator also was compiled from weather station data where daily high temperatures were recorded. The zone numbers are based on the average number of above 86 degree days we've experienced each summer. (Zone 1 equals less than one heat day a year while zone 12 experiences more than 210 heat days per year.) Steamboat falls into AHS heat zone 4. Again, if your garden faces south and receives no relief from the sun, you may need to purchase plants hardy in heat zone 5.
In catalogues and on the plant information stakes in nurseries, you should look for these two numbers. Note that not all plants have been rated yet for the heat zones since it is a relatively new indicator.
That being said, hardiness zones and heat zones simply are guidelines to help you choose plants most likely to survive here. Throughout the Steamboat area, gardeners have challenged the 'conventional wisdom' and successfully grown plants that supposedly will not tolerate our environment. And some gardeners have been able to create microclimates within their gardens to help protect some of the more tender plants.
So, have at it. Enjoy the catalogues, know which plants will likely be sure bets in your garden and know which plants you might be taking a gamble on.
Deb Babcock is a Master Gardener through the Colorado State University Cooperative Extension office in Routt County. Questions? Call 879-0825 or visit our website at http://rcextension.colostate.edu.