CNGA LooseLeaf Aug/Sept 2019

15 2020 Plant Ideas from CSU Trials By Dr. James Klett, Professor & Extension Horticulturist Colorado State University Each year, Colorado State University receives about 120 or so new perennials that have been introduced in the last three years. We do a three-year perennial trial where we keep each plant for three springs and the two winters in between. Here are some trends with perennials in our trials for their first year in 2019. One interesting trend is hybridization between some of the more common perennials. We’re seeing more hybrids like between rudbeckia and echinacea. We have them in our trials this year, and their supposed to be a little more heat tolerant and work better in containers. The Summerina® series is a good example of this. Another trend is more breeding of dwarf perennials. Salvias, for instance, used to grow to 18 and 24 inches or even taller. New varieties are now topping out at 12 inches, for use in containers and smaller landscapes. Instead of just using annuals in containers, the trend is towards using more perennials in containers. Danzinger has come up with a whole dwarf series for this purpose. We have 12 plants from Dutch Heritage in this year’s trials, and they have a lot of perennials that can grow in mixes in containers. This year, a mini climber rose called ‘Cherry Frost’ was introduced by Star Roses. It features small clusters of blooms, is self-supporting, and grows to only 6 feet at the most, so could be used in smaller landscapes. A third trend is the use of more colored foliage in perennials. Even some of the Russian sages are getting both dwarfer and more colorful with a yellower chartreuse foliage. We’ve seen the colorful foliage on coral bells for years, but now we are seeing it more with other traditional perennials. It amazes me to see how breeders keep expanding the plant palette. It’s always interesting to see what happens, and we will see how they perform for the Rocky Mountain region and Colorado in the trials at CSU, Welby Gardens and other sites this summer. LooseLeaf  Aug/Sept 2019 colorad o nga.org