Jane Rozum, Douglas County Extension
Ornamental grasses are indispensable for today’s landscapes.
Not only do they have low water, nutrient and maintenance characteristics, but
they give a unique and naturalistic appearance in both commercial and homeowner
landscapes. They can function as a screen or background plant, accent more
colorful plants, or stand alone in groupings. It is no wonder that sales of
these resilient grasses have risen 61% in the last 10 years.
The National Ornamental Grass Trials was launched in 2012.
This three-year study at 17 sites around the country was coordinated by Dr.
Mary Meyer at the University of Minnesota. Colorado State University
participated in the trials and was the only site in the Intermountain West. Twenty-two cultivars of Panicum (Switchgrass) and Schizachyrium
(Little Bluestem) were included in the trial.
The trial evaluated whether the grasses survived minimal cultural inputs
and also which plants thrive and possess desirable characteristics under
Colorado weather conditions. All the grasses were watered at 50% of bluegrass reference
evapotranspiration, which is about ½” of water per week, with no amendment to
soil at planting or fertilizer for the duration of the trial. Wood mulch was
added around the plants in 2013 to control weeds. Fall of 2015 was the last data
Colorado State evaluated the plants using a landscape impact
rating scale to rank each plant’s appearance and sustainability parameters.
This scale ranks attributes such as growth habit, lodging, floral impact,
winter injury and disease or insect damage. Overall, most of the cultivars did
very well in the CSU trials. We’ve
included photos and descriptions of the best of the trial plants over the three
years of the trial.
Panicum virgatum ‘Dallas Blues'
· Selection from seedling in Dallas, Texas home landscape
· Broad steel blue to gray-green foliage, leaves ¾-1-1/2” wide; bold textured
· Purplish panicle inflorescence
· Mature height: up to 5 ½ feet
Panicum virgatum ‘Northwind’
Selection from Northwind Perennial Farm in
Perennial Plant of the Year, 2014
Upright, narrow growth habit ; possibly a substitute
for Calamagrostis x acutiflora ‘Carl
Foliage blue/green, inflorescence green/tan
Panicum virgatum ‘Shenandoah’
Selected in Germany from seedlings of ‘Hanse Herms’
Leaves initially green in spring, red in July, wine-colored in
Upright, broad growth habit
Mature height: 4 feet in flower(tan)
Panicum virgatum ‘Thundercloud’
Upright vase growth habit
Wider, blue-green leaves up to 1 inch
Pinkish panicle inflorescence give appearance of
cloud above leaves
Schizachyrium scoparium ‘Blue Heaven’™
(Minn Blue A)
| 'Blue Heaven'|
Upright, open growth habit
Light blue foliage
Fall color: Deep pink-burgundy with copper
Schizachyrium scoparium ‘Carousel’
Compact, upright growth habit
Blue-green-gray leaf color
Fall color- copper, mahogany
Mature height: up to 2 feet