Staff \u2014 February 18, 2016<\/p>\n

\nAt Colorado State University in Fort Collins, it\u2019s not just the students who are put through the paces. Plants are tested, too, and it\u2019s a rigorous trial that awaits those perennials submitted for evaluation. The university\u2019s W.D. Holley Plant Environmental Research Center (PERC) is home to greenhouses, test gardens and an arboretum\u2014if you haven\u2019t visited, maybe it\u2019s time.<\/p>\n

CSU\u2019s perennials trials comprise a continuing study of plants that are placed in a \u201cnormal\u201d garden setting\u2014 visitors are welcome to roam the grounds during daylight hours\u2014 and the best selections each year are tapped for \u201cTop Performer\u201d status. Several that show promise, but are in the middle of the trial period, are deemed \u201cToo Good to Wait.\u201d<\/p>\n

Rating the Plants<\/h3>\n

Plants and flowers in the trials are rated from 0 to 5 on the following scale:<\/em><\/p>\n

\n
• 0 = Dead\/No flowers<\/li>\n
• 1 = Poor: Plants are very sick or dying, extremely few flowers<\/li>\n
• 2 = Below Average: Plants are unattractive in some form, for example: leggy growth habit; chlorotic or low vigor; flowers are few and occurring sporadically<\/li>\n
• 3 = Average: Plant appearance with growth characteristics that would be expected for the time of season; flowers would be few but uniform across the plants<\/li>\n
• 4 = Good: Plants look attractive (foliage, growth habit, etc.); flowers are blooming strong and showy<\/li>\n
• 5 = Excellent: Plants are very healthy and uniform; flowering is impressive<\/li>\n<\/ul>\n

  The Perennial Trial Committee awards Top Performer to plants that have been in the ground for two winters and three growing seasons. The Too Good to Wait category is to acknowledge an upcoming plant that has been in the ground one winter and two growing seasons and has shown excellent performance thus far in the trial.
  \nIn 2015, three year-two winter herbaceous perennial trials continued at PERC, and 12 different companies from around the world entered 103 taxa. There were a total of 211 different taxa of herbaceous perennials in the trial. The 2013 entries were evaluated for three years twice a month during the growing season, and photographs were taken at each evaluation. Photographs from all dates were reviewed at the end of 2015 season to determine these \u201cTop Performers.\u201d<\/p>\n

  2015 CSU \u201cTop Performers\u201d<\/h3>\n

  <\/p>\n

  Coreopsis verticillata \u2018Mayo Clinic Flower of Hope\u2019 (PPAF) or \u2018Electric Avenue\u2019<\/em><\/strong><\/span><\/p>\n

  Coreopsis verticillata \u2018Mayo Clinic Flower of Hope\u2019 PPAF, or \u2018Electric Avenue\u2019<\/strong>
  \n(Electric Avenue coreopsis; Creek Hill\/Eason)<\/p>\n

  Bright yellow flowers covered the plants over a very long bloom period. Plants were sturdy, compact and uniform from spring to fall. Fine textured foliage and a nice flower shape contributed to a very pleasing overall affect. Overwintering survival was impressive both years compared to many other Coreopsis in trial. This was designated as a winner of the \u201cToo Good To Wait\u201d award in 2014 and did not disappoint in 2015.<\/p>\n

  <\/p>\n

  Festuca glauca \u2018Casca11\u2019 PP #23307 (Beyond Blue)<\/em><\/strong><\/span><\/p>\n

  Festuca glauca \u2018Casca11\u2019 PP #23307<\/strong>
  \n(Beyond Blue fescue; Skagit Gardens)<\/p>\n

  This fescue was considered to have the best blue color out there! Plants maintained a nice \u201cball\u201d shape and did not open in the middle, remaining very uniform even after two hard winters and three growing seasons. Flower stems were very few in 2015 and faded into foliage for a superior appearance. This is an improved variety over older ones for foliage color. Beyond Blue was designated as a winner of the \u201cToo Good To Wait\u201d award in 2014 and did not disappoint in 2015.<\/p>\n

  <\/p>\n

  Helleborus \u00d7 ballardiae \u2018COSEH 810\u2019 (USPP #22350 ; Gold Collection\u00ae Merlin hellebore)<\/em><\/strong><\/span><\/p>\n

  Helleborus \u00d7 ballardiae \u2018COSEH 810\u2019 USPP #22350<\/strong>
  \n(Gold Collection\u00ae Merlin hellebore; Skagit Gardens)<\/p>\n

  Flowers emerged with a pink color that is brighter than most and then matured to shades of dusty rose. Blooms were held above foliage, creating an impressive display. Plants were more compact, with long-lasting, dark-green foliage; they required very low maintenance.<\/p>\n

  <\/p>\n

  Helleborus \u00d7 ballardiae \u2018COSEH 890\u2019 (Gold Collection\u00ae Maestro hellebore}<\/em><\/strong><\/span><\/p>\n

  Helleborus \u00d7 ballardiae \u2018COSEH 890\u2019<\/strong>
  \n(Gold Collection\u00ae Maestro hellebore; Skagit Gardens)<\/p>\n

  Shiny, dark green foliage appeared almost black at times toward the end of the season. Flower petals emerge a deep pink with white and mature to a creamy white with shades of dusty rose on the back side. Flowers covered the plant from side to side and were very prolific. Plants were compact with good vigor.<\/p>\n

  <\/p>\n

  Helleborus \u00d7 argutifolius \u2018COSEH900\u2019 PPAF (Gold Collection\u00ae Snow Fever hellebore)<\/em><\/strong><\/span><\/p>\n

  Helleborus \u00d7 argutifolius \u2018COSEH900\u2019 PPAF<\/strong>
  \n(Gold Collection\u00ae Snow Fever hellebore; Skagit Gardens)<\/p>\n

  The speckled green and white variegation makes this a great foliage plant that will add sparkle in shady areas even when not in flower. Sturdy plants have proved hardy over two winters that have been too severe for other variegated varieties of Hellebore.<\/p>\n

  <\/p>\n

  Perovskia \u2018Novaperlac\u2019 (Little Lace\u2122 Russian sage)<\/em><\/strong><\/span><\/p>\n

  Perovskia \u2018Novaperlac\u2019<\/strong> (Little Lace\u2122 Russian sage; Star Roses and Plants\/The Conard-Pyle Co.)<\/p>\n

  Growth habit is unique as it combined a shorter plant with great uniformity. Purple flower spikes were long lasting and created a lot of flower power. The tidy, compact plants were a significant improvement over typical sprawling Russian sage in general. It makes a good choice for xeric areas.<\/p>\n

  <\/p>\n

  Rosa \u00d7 hybrid Sunrosa\u2122 Red (Sunrosa\u2122 Red rose)<\/em><\/strong><\/span><\/p>\n

  Photo courtesy of Suntory Flowers Limited<\/p>\n

  Rosa \u00d7 hybrid Sunrosa\u2122 Red<\/strong>
  \n(Sunrosa\u2122 Red rose; Suntory\u00ae Flowers)<\/p>\n

  Constant red flowers and impressive growth habit made this plant attractive all season. Glossy dark green foliage had no signs of chlorosis or disease. Red flowers did not fade and bloomed steadily from mid-June through October. Small foliage and a dwarf compact growth habit made this a good choice for smaller or mid-size landscapes. The compact growth habit is maintained without any pruning. This was designated as a winner of the \u201cToo Good To Wait\u201d award in 2014 and did not disappoint in 2015 either.<\/p>\n

  <\/p>\n

  Veronica \u2018Novaverblu\u2019 (Dark Blue Moody Blues\u2122 veronica)<\/em><\/strong><\/span><\/p>\n

  Photo courtesy of Star Roses and Plants<\/p>\n

  Veronica \u2018Novaverblu\u2019<\/strong>
  \n(Dark Blue Moody Blues\u2122 veronica; Star Roses and Plants\/The Conard-Pyle Co.)<\/p>\n

  Long bloom period and the abundant spikes of dark blue flowers made this a standout. Plants were very uniform and had excellent winter hardiness. Additionally, plants had good resistance to disease and there was no sign of powdery mildew. The entire Moody Blues\u2122 series was noted for superior performance.<\/p>\n

  <\/p>\n

  Veronica \u2018Novaverpin\u2019 (Pink Moody Blues\u2122 veronica)<\/em><\/strong><\/span><\/p>\n

  Photo courtesy of Star Roses and Plants<\/p>\n

  Veronica \u2018Novaverpin\u2019<\/strong>
  \n(Pink Moody Blues\u2122 veronica; Star Roses and Plants\/The Conard-Pyle Co.)<\/p>\n

  Flowers were noted for having exceptionally uniform, perfect spikes of light pink flowers that helped create an impressive overall display. Growth habit and flowering were very uniform. The overall height was taller than others in the Moody Blues\u2122 series but still maintained a nice, compact habit. The entire Moody Blues\u2122 series was noted for superior performance.<\/p>\n

  Class of 2014 \u201cToo Good to Wait\u201d<\/h3>\n

  The following two plants impressed the Perennial Trial Committee so much that they designated the category name: \u201cToo Good to Wait Performer.\u201d<\/p>\n

  <\/p>\n

  Brunnera macrophylla \u2018Alexanders Great\u2019<\/em><\/strong><\/span><\/p>\n

  Brunnera macrophylla \u2018Alexanders Great\u2019 PP25,789<\/strong>
  \n(Alexanders Great brunnera; Terra Nova Nurseries Inc.)<\/p>\n

  This is a unique brunnera of \u201cmonster\u201d growth proportions, which is an excellent choice to add structure to the garden. The large size also helped show off the heavily silvered leaves resulting in a dramatic statement for the garden. It makes a great foliage plant for shady areas but also had a good display of blue flowers that created a light, airy appearance.<\/p>\n

  <\/p>\n

  Heuchera \u2018Forever Purple\u2019 PPAF (Forever Purple coral bells)<\/em><\/strong><\/span><\/p>\n

  Heuchera \u2018Forever Purple\u2019 PPAF<\/strong>
  \n(Forever Purple coral bells; Terra Nova Nurseries Inc.)<\/p>\n

  Leaves had an intense purple color with a shade of red that was maintained all season. The glossy foliage seemed to make the color \u201cbounce\u201d off the leaf. It is grown mostly for attractive foliage, which also has fluted edges. Plants had good vigor and a uniform growth habit.<\/p>\n

  For more information about the Colorado State University trials program, visit http:\/\/www.flowertrials.colostate.edu\/trial_garden.php?category=Perennial. The trial program is supervised by James Klett, Director of PERC and Professor and Extension landscape horticulture specialist in the Department of Horticulture and Landscape Architecture at Colorado State University in Fort Collins\u2014where he\u2019s worked at perfecting plants for 35 years. He can be reached at [email protected].<\/p>\n

  Photos courtesy of Colorado State University, unless otherwise noted.<\/p>\n","protected":false},"excerpt":{"rendered":"

  Staff \u2014 February 18, 2016 At Colorado State University in Fort Collins, it\u2019s not just the students who are put through the paces. Plants are tested, too, and it\u2019s a rigorous trial that awaits those perennials submitted for evaluation. The university\u2019s W.D. Holley Plant Environmental Research Center (PERC) is home to greenhouses, test gardens and […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-319","post","type-post","status-publish","format-standard","hentry","category-nursery"],"yoast_head":"\n