The lower regions of the Great Plains have much higher summer temperatures than the states to the north, although it shares the high winds and unpredictable weather found throughout the Plains.
Missouri Botanical Garden in St. Louis and Oklahoma State University in Oklahoma City held trials in 2015, testing which plants performed best in their regional weather.
Here are a few notes on each trial before we get to the photo gallery of top performers:
Missouri Botanical Garden
Missouri Botanical Garden’s field trials experienced cooler weather in 2015 than most summers. There were less than 14 days of temperatures over 90˚F. Most days were in mid to high 80s, with much less humidity. Throughout May, June, and part of July, rainfall was much heavier than normal. August and early September were very dry and irrigation became necessary.
There were 165 items and a total of 4,149 plants. Missouri Botanical Garden’s trials are located in the Kemper Center for Home Gardening in six separate beds. Each partial or whole bed was dedicated to a different breeder or distributor.
The early cool, wet weather was hard on catharanthus, petunias, and pentas. They all got a late start because of cool, wet weather but thrived once the sun returned on a regular basis.
Oklahoma State University
This was a year to enjoy the trials to the max. It was surprisingly wet at the Oklahoma State University-Oklahoma City trials, with frequent rains through June and beyond. Temperatures were mostly moderate for this region. Many of the 100 entries performed quite well throughout the entire trialing season.
Wary of trialing petunias in the ground due to disease pressure, OSU trialed them out of large Smart Pots™. Many people were taken with their showy and consistent presentation. The sun trials bed aisles were kept clean with a swath of geotextile; this proved to be a significant help as the abundant rains encouraged vigorous weed pressure.