See below for tables with results and photos
Winters in the upper Midwest are long and cold and as a consequence, “cabin fever” is not uncommon. It only takes a sunny day of moderate temperatures in early March for many people to go to the garden centers to buy plants to put in their gardens. Good growers/garden center managers dissuade customers of planting because the chances of frost damage are still very high. We thought that it would be useful for retailers to have plants that have a good chance to survive the cold weather until “real” (not “calendar”) spring comes. With such information available, retailers could still have a sale and keep customers happy by selling plants that will not die due to low temperatures. On a similar vein, why not extend the beauty of gardens by having plants that can take the first frosts in the fall?
Starting in spring of 2009, the Ohio State University Annual Trials re-instated a cold tolerance evaluation for bedding and balcony plants. Consumer and professional interests have driven this re-initiation so that the tolerances and market potential for new and existing plant material that tolerates, and prefers, cooler growing conditions. The trial has also been split into two separate trials, one in spring to show early initiation and heat tolerance and one in the fall to show longevity and survival in cold conditions.
In the past the program focused on pansy and viola cultivars, which still make up a large segment of the entries, but the scope of the evaluation was widened to include all cold tolerant plant material. Two companies, Ball Horticultural and Sakata Seed, have opted to participate in this trial, sending seeds to be grown and produced according to industry standards.
Seeds were sown December 30th, 2008 (week 1) in 288 cell count plug trays, plugs were treated once with B-Nine at 1250ppm 24 days following sowing. Plugs were grown according to company recommended guidelines. Plugs were transplanted February 3rd (week 6) into 4.5” pots and grown according to company recommended guidelines until March 23rd (week 13) at which plants were moved outside for hardening. Finished pots were planted in the ground on April 2nd, mulched and fertilized with 200ppm N.
Temperatures were, on average, above normal for Central Ohio, but temperature did drop below freezing on occasion (Figure 1). Photos were taken March 27th during the outdoor phase of finished growing and April 24th, once plants were established and had been growing for three weeks.
Consumer evaluations were done on April 28th and and May 12th and will be done every two weeks until removal July 1st. The results of these two first evaluations can be viewed in Table 1. Ratings are based on a relative scale of 1-5 (5 being best, 1 being least) to indicate the preference of the Master Gardener Volunteers performing the evaluation. The third evaluation is shown in Table 2.
A brief flowering schedule can be seen in Table 3 and associated with the March 27th photos. Percentages are based on the number of plants in flower out of available plants. So, three of ten plants in flower would be 30% in bloom. Plants need only one flower open or opening to be considered “in bloom”.
The most preferred plants* following the first two evaluations are:
Pansy Panola XP Beaconsfield (4.72), Pansy Panola XP True Blue (4.58), Viola Venus Lavender Pink (4.36), Pansy Panola XP Marina (4.28), Pansy Panola XP Yellow Blotch (4.26)
*Scores are shown in parentheses
Preliminary conclusions can be drawn from the first two evaluations:
- The Panola series was the earliest blooming series evaluated.
- The flowers of the XXL and Matrix Series were the largest, but there were fewer blooms that developed later than those of the Panola, Ultima Radiance, Venus and Rebelina Series.
- Consumer preference for the XXL and Matrix Series increased over time, but the Panola Series was still the most popular, followed by Venus and Rebelina Series, respectively.
- Pansies and Violas are still the preferred cold weather annual, but data shows there is still preference for variety. More data is needed to make assumptions about the overall popularity of cold weather annuals.
- Plants that were not in flower received a much lower rating than plants in flower, i.e. Dianthus.
ACNOWLEDGEMENTS
We would like to take this opportunity to thank our participating companies, Ball Horticulture and Sakata Seed, and companies that through their donations make this trial possible, Dillen Products Inc., and SunGro Horticulture. We would also like to thank the OSU staff member, Dave Snodgrass, for his assistance. We are currently in the planning stages of our fall 2009 and spring 2010 trials if your company is interested in participation, please use the contact information below to discuss the options.
For additional information on results or how you can participate in these trials, please contact Bart Hayes hayes.238@osu.edu or Dr. Claudio Pasian pasian.1@osu.edu.
