Q&A with Tony Avent

How did you get involved?

A: I was at a meeting and standing in the lunch line and noticed the person behind me had a USDA-ARS badge. I asked about the new map that I’d seen unveiled and was getting ready to be launched.

As it turns out, USDA had given funds to start work on the map, but hadn’t seen the result and certainly hadn’t approved its release. All of the 2003 copies were subsequently stamped with the words “draft copy” and pulled. The 2003 version was woefully inadequate and used a small data set from several warm years, which would have encouraged gardeners to be planting plants that would not survive long term in their zone. As it turned out, some other nurserymen had expressed similar concerns.

So you helped halt a bad version from being released?

A: In a way.

How many nursery-industry people were on the committee?

A: There were a few. Bob Lyons from Sunleaf Nursery, Bill Hendricks from Klyn Nurseries [both in Perry, Ohio] and a few others.

Just how many years of data were used to create the new map?

A: We strongly argued for a 30-year data set, and the USDA agreed, since our recent climatic history has been one of 15-year warm cycles followed by 15-year cool cycles. The previous 1990 map used only 13 years of data from a very cold period.

Beyond more years, what else did the nursery people argue for?

A: The industry folks talked about how the map was used, why it was important, etc. I asked for several other overlays to the map, which we were promised would happen in future versions once this base map was done.

These would be max temps, minimum temps, precipitation and day/night temperature variation overlays. Where the advisory committee really worked was to review the draft map and find areas where we thought the data was incorrect or incomplete, and subsequently reviewing the updates as they were completed.

Are there any other new features?

A: The best feature is the interactive map, where you can enter your ZIP code and then click around anywhere in your region for warm and cold spots. This is a fabulous tool for garden centers and nurseries, whose territory covers more than one zone. It will allow them to better cater plant recommendations and hopefully increase the success rate of gardeners.

Predictably, the media caught wind of the new map and thought it showed a case for global warming. But that’s just not the case, right?

A: You can’t really compare the two maps since one was 13 years of cold, and the new map is 30 years with 15 of warm and cold each.

There is no dispute that we have been warmer the last 15 years. Up until 1996 in Raleigh, we could count on hitting 0°F two out of every 10 years. Since 1996, we haven’t dropped below 6°F.

Whether we are heading into a 15-year cooling cycle, as historical trends have shown, is anyone’s guess.