FORT COLLINS, Colo. — Growers, landscape contractors and homeowners will want to plant some of these winners in their gardens in the fall of 2019 from our 2018-2019 Cool Season Trials. These trials included 121 different varieties of cool season plants. These plants were planted on October 30, 2018 and grown through the fall, winter and early spring of 2019. Additional water was added to these trial a total of ten times from October 30 through early April. Watering was done when temperatures were above 40 degrees Fahrenheit and soil was dry. Our lowest temperature recorded during the period was -8 F in early March. We recorded frost damage, flowering data and overall appearance on a weekly basis when not covered in snow. We had below average snow cover during the winter months which resulted in some damage to the plants but provided a still provided a good trial as the winners that follow are truly the “toughest of the tough”.
The Flower Trial Garden Committee evaluated these Cool Season Trial in May 2019 and picked the following six top performers. The six winners include:
Plants were noted for superior cold hardiness and good uniformity. Would make a good companion plant for pansies. Provides color for both fall and early spring. Flowers are attractive with shades of orange and yellow. Plants had an attractive busy growth habit and dark green foliage.
Great uniformity even after a very harsh winter made this the best Dianthus in the trial. Plants had abundant bud count and excellent vigor with attractive green foliage.
The rich, velvet purple flower color was very impressive. Prolific blooming and a mounded growth habit made a great looking plant. Plants were a little more upright and very uniform overall.
Flowers were noted for their attractive blend of blue and yellow flowers that can’t help but “create a happy feeling”. Plants were very uniform with excellent vigor and great flower coverage. Nice mix of flowers also produce labor savings for growers that don’t have to combine other plants to create the same effect.
Vibrant flowers had an impressive contrast for a very bold appearance. Blooms were noted for standing up with their face held upward to create maximum flower power. Plants had excellent winter survival and were very uniform overall.
The rich, velvet purple flower color was very impressive. Prolific blooming and a mounded growth habit made a great looking plant. Plants were a little more upright and very uniform overall
— Jim Klett, Colorado State University Extension
For more news from Colorado, click here.