CNGA LooseLeaf April/May19

20 colorad o nga.org LooseLeaf April/May 2019 Hemerocallis x ‘Betty Woods’ – Betty Woods Daylily This daylily has been in our trials since 2004, and grows to about 18 to 36 inches in height with a mounding growth habit. The flowers are a bright yellow color, fragrant and double, and stand well above the foliage. It flowers early in the season and reblooms throughout the summer. It was given the Stout Silver medal from the American Hemerocallis Society in 1991. Knautia macedonica – Pincushion Flower We have had this plant in our trials since 2008. It has a very long bloom period from spring into fall. It has a quarter growth habit and is an excellent choice for borders or rock gardens. The reddish/purple flowers have a unique color. It also prefers dryer soils, especially during the winter months. Veronica alpina ‘Alba’ – White Alpine Speedwell This perennial appears tolerant of a wide range of soil pH’s and performs best in full sun. It is an excellent rock garden plant with showy white spike-like flowers from summer into the fall. It has been in our trials since 1997, so it is definably cold hardy and adaptable to Colorado conditions. It also has good deer and rabbit resistance. Gypsophila paniculata ‘Pink Fairy’ – Pink Fairy Baby’s Breath This plant is a favorite for butterflies, and blooms early summer all the way to fall. It is tolerant to a wide range of soil pH’s and is fairly drought tolerant and deer resistant. It has been in our trials since 1996, and makes an excellent fresh and dry cut flower. CSU RESEARCH UPDATE By James E. Klett, Ph.D. Professor & Landscape Horticultural Specialist Colorado State University At Colorado State University, we continue to evaluate herbaceous perennial performance at our Perennial Demonstration/Teaching/ Research and Outreach Garden. This garden was moved to its present location north of the University Center for the Arts in 2017, from the former perennial demonstration garden at the Plant Environmental Research Center. Plants in this garden are planted in more traditional perennial borders and evaluated yearly for their hardiness and landscape qualities. The following seven herbaceous perennials are superior in their performance over the last 10-plus years. They are definitely adaptable to our Colorado climate and should be planted more in gardens in our state. Some Proven Herbaceous Perennials fromCSUTrials Thalictrum speciosissimum – Dusty Meadow Rue This plant is one of the oldest perennials in the garden, and was planted in the early 1980s. It is a long-lived and low-maintenance plant that is naturally resistant to deer and rabbits. It can grow in deep shade to full sun, and is an excellent pollinator plant. However, it can be susceptible to powdery mildew. Solidago speciosa ‘Wichita Mountains’ – Wichita Mountains Showy Goldenrod This native North American perennial is an excellent pollinator plant and can grow up to 30 inches in height. We have had it in our trials since 2012. Overall, it is a low- maintenance plant. The yellow flowers in late summer into the fall are extremely showy. This plant is also more deer and rabbit resistant. Festuca cinerea ‘Elijah Blue’ – Elijah Blue Fescue This cool season grass provides good color and interest all year long. We have evaluated it since 1997, and it is definitely drought tolerant. The flowers in June are not spectacular since it is mainly grown for the distinctive blue foliage color. It pairs especially well with purple foliage plants in a rock garden. These are just seven of many outstanding and very dependable perennials in our demonstration garden. Plan to visit during the 2019 season since there is always something at its peak in this garden throughout the season.