On
Newsstands
Now
Current Issue
Proven Winners' Summerific Cherry Cheesecake rose mallow–hibiscus hybrid was one of the CSU trial garden's top performers. Courtesy of David Staats

The Best New Perennials to Plant in Colorado

Colorado State University shares the results of its multiyear trial of new cultivars.

By |

Front Range gardeners know our homeland holds particular landscaping challenges: We never plant before Mother’s Day, and we frantically put twinkly lights on our fruit trees during those inevitable spring snowstorms. We need perennials that can withstand summer’s intense sunshine and our unpredictable winters.

Thankfully, Colorado State University’s team of horticulturists has our weeding-weary backs with its 10-year-old, open-to-the-public perennial trial garden—a literal testing ground to see which new varieties thrive in our finicky climate. (CSU has also been evaluating annual flowers for 30 years.) “There are so many perennial plants coming from breeders,” says Jim Klett, a professor and extension landscape horticulturist at CSU who oversees the research. “We want to understand what’s going to grow best here in Colorado.”

To that end, CSU receives samples of cultivars that’ve been introduced in the past few years from commercial breeders. (The plant companies pay a fee for trial inclusion that covers the cost of growing and helps fund a graduate student who manages the research.) Seeds are planted in the spring near the arts complex, and they receive basic watering and fertilization. CSU tracks plant growth with biweekly measurements and photos.

Ultimately, the trial observers look for plants that provide visual interest throughout the year, rather than one short-lived burst of color, Klett says. The plants need to make it through two winters (they’re judged in November, so they see three full summers) with only minimal care and must also prove disease- and insect-resistant. CSU then releases its new class of top performers each April—just in time for the start of Colorado’s planting season.

To try out the winners at home, ask for them at your local, independent nursery; CSU works with the Garden Centers of Colorado, which has shared the recommendations with its members. “These might be tougher to find at the big-box stores, but most of the independent garden centers tell me they’ll be ready with these plants,” Klett says. Here’s the complete list of top-performing new perennials.


Great Reads