COLUMBIA — Expect to see more crepe myrtles on the MU campus in coming years.
The first update in the U.S. Department of Agriculture's plant hardiness map since 1990 has caught the attention of the director of the Mizzou Botanic Garden and other local horticulturalists.
Pete Millier, director of campus facilities, landscape services and the campus botanic gardens, said some plants will be seen around campus more than in the past under the new guidelines for plants that can survive mid-Missouri winters.
One of these is the shrub crepe myrtle, which in the past has been visible along the walkways between Ellis Library and Speakers Circle. There are plans to plant more outside the Agriculture Building this spring.
"It is really a beautiful plant," Millier said. "You can get any number of colors out of it. It does well in a hot, dry summer. It's really quite a showstopper when it's in full bloom."
The USDA released an updated plant hardiness zone map on Wednesday that relocates Boone County from Zone 5B to Zone 6A.
The change means that Columbia and other locales in the new Zone 6A experienced an average lowest temperature between 1976 and 2005 that was 5 degrees warmer than the years 1974 to 1986 that were used to create the 1990 map.
Different zones can accommodate different plants. Steven Sapp, owner of Strawberry Hill Farms south of Columbia, said he pays attention to the map.
The map is divided into different zones based on the average extreme minimum winter temperature for an area, covering 10 degrees Fahrenheit in each zone, according to the USDA website. The zones are then divided into 5-degree half-zones. For 6a zones that include Boone County, the average extreme minimum temperature between 1976 to 2005 was minus 10 to minus 5 degrees Fahrenheit.
Marie Pasley, vice president of Heart of Missouri Master Gardeners, said the map is important for people looking to purchase plants.
"When you buy anything, plant material, you need to see where you can grow it," Pasley said. "We use [the map] all the time to educate people when they're making purchases."
Sapp said he uses knowledge of the hardiness zones when determining which plants to sell at Strawberry Hill Farms.
"The only time that I worry too much about that is when I'm ordering something new that I'm not familiar with," Sapp said. "Some people aren’t even educated on what zones are. We do their homework for them, and if it won't work here, we don't sell it as a perennial."
Although she uses the USDA zones for informing others, Pasley said she does not always follow the guides.
"Individually, all of us probably try growing different things in different areas," Pasley said. "That's been going on for many years. Following the hardiness zones guarantees the most success."