Top Picks for Off-Season Color

By James E. Klett, Ph.D., Professor & Landscape Horticultural Specialist, Colorado State University

In the 2018–19 Cool Season Trials, we evaluated 122 varieties. They were planted in late October 2018, and grown in our trials till early June 2019. An evaluation day was held on May 15, 2019, where members of the Annual Trial Garden Committee selected our “Top Performers.”

During the trial period, all of the varieties were monitored and observed weekly. They were watered and fertilized initially until our irrigation system was winterized (mid-November 2018). After that date, they were hand watered when the soil was dry and temperatures were above 40°F. Plants seem to have a different establishment period as it was cold and rainy when planted, and then there was a hard freeze about a week later. With the cold temperatures, difficult establishment of rooting and lack of snow cover early in the winter, heaving of plants was much more of a problem than in past trials. The overall weather during December through February was cold, windy and fairly dry, though we had three significant snow storms from March to May. The trials this year showed that certain varieties are hardier than others and that they can withstand the harsh winter of Colorado.

Pansy ‘Joker Mahogany-Gold’ from Benary
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.


Pansy (Trailing) Freefall® XL Azure Blue from Floranova
Plants were noted for strong flower power and a very uniform overall appearance. Prolific blue flowers covered the plants. Plants were vigorous and would make a nice ground cover as well as having a good trailing growth habit that would work well for containers.

Viola ‘Fuseables® Sunny Skies’ from PanAmerican Seed
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. The nice mix of flowers also produces labor savings for growers that don’t have to combine other plants to create the same effect.

Viola ‘Admire® Deep Purple Face’ from Benary
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.


Cheiranthus ‘Sugar Rush Orange’ from Floranova
Plants were noted for superior cold hardiness and good uniformity. They would make good companion plants for pansies. They provide color for both fall and early spring. Flowers are attractive with shades of orange and yellow. Plants had an attractive growth habit and dark green foliage.

Dianthus ‘IQ Blueberry Picotee’ from Floranova
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.


Growers will want to note and grow these six varieties and landscapers hopefully will plant these varieties for excellent fall, winter and early spring flower color for the 2019-20 season.