Posted by Jim Klett, Professor, CSU Department of Horticulture and Landscape Architecture
Our three year (2 winter) herbaceous perennial trials at
Colorado State University continues to grow each year with 115 new entries for
a total for 270 entries. Plants are evaluated for plant vigor, uniformity, floriferousness
and tolerance to environmental and biotic stresses. The following six
perennials have been awarded the 2019 “Top Performer” perennial designation
after performing superiorly for three growing seasons and two winters in our
Fort Collins, Colorado trials.
A complete report on the perennials in the trial can be
viewed at www.flowertrials.colostate.edu
under Perennial Trials menu.
Millenium Ornamental
Onion from Eason Horticulture Resources and Stonehouse Nursery
(Allium hybrid
'ALLMIG1')
This was a definite “show stopper” plant that was described as having
an “insane” amount of blooms. Flowers
were a nice shade of pink and were a favorite of many bees and
butterflies. The flowers combined well
with a nice compact plant with clean foliage and very uniform growth
habit. Blooming lasted a long time and
flowers did not lodge even with overhead irrigation. It has been reported to grow well even at
8,000’ in the mountains. Removal of
spent blooms can result in some repeat blooming or can be left for winter
interest. Judges were in unanimous
agreement to designate it as a winner.
Kahorie® Scarlet Border Pinks from Dummen Orange
(Dianthus x hybrida
Kahorie® 'Scarlet')
Very showy in the spring with a very vibrant color and attractive
plants. Flower color was not a true
scarlet but a beautiful shade of hot rose or cherry. Plants had superior winter hardiness that was
consistent over three years and did not die out in the center as did many other
Dianthus. Plants were attractive even
when not in bloom with a nice tidy, compact growth habit.
SUMMERIFIC® Cherry Choco Latte Rose Mallow from Walters Gardens, Inc.
(Hibiscus x hybrida 'Cherry Choco Latte'PPAF)
Large, two tone blooms were captivating with a striking combination of
pink and white. It makes a great choice
for providing color late in the season.
Plants were relatively low maintenance as the old blooms were
self-cleaning. Foliage had shades of
dark red that was maintained throughout the season. Plants also had a nice growth habit that did
not lodge and the mid-size height made a good balance with the flower size.
Lami™ Dark Purple Spotted
Deadnettle from Danziger
(Lamium maculatum 'Dark
Purple')
Dark purple flowers combined with dark green foliage and a very uniform
growth habit to make a very impressive groundcover. This versatile plant did not burn in the sun
and did well in the shade. It has also
been reported to look great even at 8,000 feet elevation. Plants have superior vigor and provide a long
period of bloom.
Bandwidth Maiden Grass
from Darwin Perennials
(Miscanthus sinensis
'NCMS2B'PP29460)
This is a good selection for today’s smaller gardens and landscapes as
the plant maintains a nice uniform growth habit that is only 3-4’ in
height. Plants did not bloom but foliage
is very attractive with yellow stripes running across the blade. The variegated foliage did not revert and was
impressive all three seasons. Flowers
are not needed for interest as the yellow and green contrast in the leaves is
very showy.
GRANITA® Orange Ice Plant from
Plant Select®
(Delosperma ‘PJS02S’)
Bright, iridescent orange flowers blanket the plant creating an
impressive show of flower power. Large
flowers bloom over a long period. Plants
make a very attractive ground cover as the beautiful green foliage forms a nice
dense mat that tightly hugs the ground.
Vigor is excellent and makes a good spreader. Cold hardy and well suited for this area.