For at least 6 years, most areas of the Greater Kansas City region have not had winter temperatures much below zero Fahrenheit. When I moved here 13 years ago I was constantly reminded of prior bitter cold in excess of -20F and that the area, save for some sheltered spots in the city was “zone 5” with minimum temperatures from -10F to -20F on average. Over the past 13 years of living here, the coldest we have recorded at Powell Gardens at our official weather station was -10F (rounded down). We have even had one winter with a minimum of only+17F! Have we migrated into a new warm zone 6 (average low between 0 and -5F) or are we just in a short mild stretch soon to be broken by a bitterly cold winter?
The region’s plants are showing our climate change. Our crape myrtles (Lagerstroemia) were just dieback perennials when I moved here but now are large shrubs and even small trees! Crape Myrtles are hardy above ground only to temperatures around -5F at best. Here, just outside our Visitor Center, gardener Shelly Bruellisauer poses next to our ‘Zuni’ crape myrtle (Lagerstroemia indica x L. faureri). Spencer Crews, Powell Gardens’ former Director of Horticulture and now Director of Omaha’s Lauritzen Gardens was astonished to see how large our crape myrtles have grown. It got down to -21F at their garden last winter! They cannot grow crape myrtles there.
Powell Gardens now has quite a few crape myrtles growing around the southern end of the Visitor Center and in the Perennial Garden. Acoma Crape Myrtle is a beautiful clean white blooming cultivar that is a Plant of Merit. Look for it just south of the Visitor Center’s Hummingbird Garden.
Hopi Crape Myrtle is a very good pink-blooming crape myrtle and can be seen just outside the Visitor Center. All the crape myrtles with these Native American names are hybrids with more hardiness than typical species. Many of the new hybrids are from the National Arboretum in Washington D.C. but many are also from Oklahoma. Look for dazzling red ‘Dynamite’ crape myrtle, purple-flowering ‘Catawba’ crape myrtle and several other cultivars in the Perennial Garden.
Lindley Butterflybush (Buddleia lindleyana) is another tender shrub that has not died back in many years and has become quite a large fountain of its pendant lavender blue flowers. This butterflybush is a favorite of hummingbirds and butterflies and can be seen just out the south end of the Visitor Center while young plants are along the steps down to the Fountain Garden. This butterflybush is sterile but does spread a bit by easily removed runners.