2012 Field Trials Reports: Pike Creek Horticulture Center, Gateway Technical College

Begonia 'Whopper Rose with Green Leaf' at Pike Creek trials

Trial manager: Kate Field, Horticulture Instructor, fieldk@gtc.edu

Location: Kenosha, WI

Planting Dates: June 5 to 10

Number of Entries: Approximately 100

Weather Conditions: The winter of 2011-2012 in Wisconsin, as in much of the country, has gone down on record as one of the warmest in almost 80 years. The summer of 2011 was the warmest since 1931-32 in Wisconsin and the ninth warmest overall dating back to 1871. Summer annuals typically hardy to Zone 7 returned this spring as perennials in our normally Zone 5 climate. Record setting temperatures in the 50s and 60s throughout February and March, and the resulting spring-like conditions, created early customer demand for garden products throughout the Midwest.

Ornamental trees and shrubs came out of dormancy early and began flowering only to be nipped by frost. This resulted in damaged flowers for magnolia, forsythia, crabapples and spring plants of all kinds. The Wisconsin fresh apple and cherry crops were severely injured.

By early September southeastern Wisconsin rainfall was still about 3.5 inches below normal resulting in low water levels in lakes, rivers and groundwater supplies. The lack of soil moisture and heat this summer was especially hard on perennial plants. Extreme wilting was seen on trees, shrubs and herbaceous perennials in August with plant death and branch dieback also apparent. Early leaf drop and fall color was also observed on woody plants. Plant injury and deaths may not be apparent until next spring, and will be worsened, if we have a winter of low soil moisture, extreme cold and no snow cover.

Retail traffic: Customer traffic was strong and steady from March through June bringing much needed sales after the cold, wet spring of 2010. Warm temperatures continued to climb in July with several continual weeks in the 90°F to 100°F range, coupled with a lack of rainfall. Precipitation from June to early September was between 25 and 50 percent below normal. The hot, dry conditions combined to create a severe drought across southeastern Wisconsin and much of the Midwest. While the demand for garden products began early in Wisconsin it also came to a crashing halt once the hot, dry weather arrived in June and customers fled their gardens for air conditioning.

Best in Show:
Begonia ‘Whopper Rose with Green and Bronze Leaf’ was a real showstopper this year. We tend to think of begonias as shade- and moisture-requiring plants, but the new hybrid begonias are much more adaptable to heat and dry conditions. Whopper has attractive shiny green or bronze leaves and huge semi-drooping flower clusters, which were beautiful in a large container in a heavily shady site. Red-flowered plants also performed beautifully in ground in a north facing planting bed. Plants are also fairly cold tolerant which helps extend their usefulness in Wisconsin.

By mid-September, the temperature was going from 80°F during the day to the mid-40s at night and this plant continued to look great! Plants have a loose, open architecture in shade and a more compact, tight habit in sunnier spots.

Begonia ‘Baby Wing Pink’ is another begonia winner from Ball Horticultural. Shiny dark green leaves contrast beautifully with shell pink flowers and dark pink buds. Plants sailed through summer’s heat in less-than-ideal begonia conditions. Planted in part sun with limited and inconsistent water, they continued to bloom all summer. They have a tight, compact habit in sun and a more open, tall habit in shade. These begonias were beautiful in containers with companions Impatiens ‘Patchwork Cosmic Burgundy,’ Ageratum ‘Blue Horizon’ and Plectranthus ‘Silver Shield.’

While these begonias did well in both sun and shade conditions, they didn’t fare so well as bedding plants under a river birch, probably due to heavy competition for water this year.

Top varieties:
1. Viola xwittrokiana Cool Wave and Spring Matrix series. Cool Wave is the next big thing from Ball Horticultural and just like the name implies, this is a spreading type pansy. The series includes Yellow, Frost and Violet Wing. Pre-germinated seed made for uniformity across the flat and very early color. These were some of the first pansies to bloom in spring along with violas. While they looked a little bedraggled in the record breaking heat and drought of summer, they are also perennial and the yellow has returned with cooler fall temperatures. The yellow seems to be the most heat and drought tolerant of the series and is making an attractive and unexpected groundcover under ‘Purple Dome’ asters. We will see how they fare over winter and if they come back next spring. One problem we had was workers pulling these plants out in summer as they appeared to be dead rather than just summer dormant.

The Spring Matrix series is designed to hold at retail without stretching in warm weather. Plants were really put to the test this spring with record-breaking warm temperatures in the greenhouse. Plants stayed compact and tight with no stretch or flopping and huge flowers. Outstanding colors in the series include Midnight Glow, Sangria, Ocean and Blue Blotch.

2. Angelonia ‘Serenita Purple’ and ‘Serenita Raspberry.’ This was another selection that really enjoyed the heat and humidity of our hot summer. Plants were extremely vigorous, self-cleaning and compact without the need for PGRs or pinching. They grew to form a uniform 10-inch tall groundcover that was very effective in preventing weeds. The raspberry color was also used in containers where its texture and color combined beautifully with Petunia ‘Shock Wave Deep Purple.’ The pelleted seed was easy to use in our automatic seeder and made this plant cost effective to use in abundance in the landscape. This heat- and drought-loving annual provides something a little different to landscapes, which keeps customers interested.

3. We have enjoyed incorporating vegetables into our trials both for their edible use and attractiveness. ‘Sweet Heat’ pepper was early to set fruit and extremely prolific. This is the perfect pepper for someone who likes just a little heat. The 4-inch long peppers were ready to pick green by mid-July and began turning red by early August. This is very unusual in that most years we barely have a long enough growing season or heat to enjoy peppers. This would be a great plant to sell in a garden center with ripe fruit on it.

4. ‘Buttercream’ shasta daisy is a perennial from Proven Winners that we have been trialing for about three years, so it has survived several Wisconsin winters. The daisy flowers start out a pale lemon color and soften to butter yellow. The flowers have an extra row of petals so they look very full. The plants are compact and full growing to about 24 inches with strong stems supporting the flower heads and absolutely no lodging. The foliage is clean and disease resistant. The plants were covered with blooms continuously for about 6 weeks.

5. Celosia ‘Fresh Look Yellow Improved’ from Ball Horticulture. We definitely saw an improvement in this series color from last year when conditions were cool and wet. This was the summer for heat- and drought-tolerant plants to shine and celosia is always a winner. ‘Fresh Look Yellow Improved’ is a bright golden yellow; the flowers are very long lasting and weather resistant. The foliage is clean, full and disease resistant. We planted this in June and it bloomed without interruption, deadheading or care for the entire summer. Later in the season, some flowers seemed to revert to the ‘cockscomb’ type but not too bad.

6. Lavandula ‘Ellagance Purple’ and ‘Ellagance Ice.’ This is one of the ‘first year flowering’ perennials from seed offered by Ball a few years ago. Lavender is a much-loved perennial but doesn’t always survive the wet, clay soil and humid conditions of Wisconsin’s summers. These plants looked especially beautiful this summer with rich greygreen foliage on compact plants with dense flower spikes on strong stems. They bloomed early and consistently throughout summer without shearing or deadheading.

The white-flowered ‘Ellagance Ice’ is a bit shorter than the purple and would make an effective groundcover. Ellagance has survived three Wisconsin winters, so it is showing good winter hardiness and cold tolerance. It has excellent disease resistance with no sign of the foliar diseases or dieback that sometimes affect other lavenders. Plants from seed filled pots quickly, and were well branched and quick to bloom making them good for retail.

To see more images, go to the Gateway Horticulture Trials Flickr page

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