Ohio State Learning Gardens
ANNUAL TRIALS 2003

In-Ground and Raised Bed Trials

by: Monica Kmetz-Gonzalez and Dr. Claudio Pasian
Department of Horticulture and Crop Science
The Ohio State University

The Ohio State University Learning Gardens Annual Trials were expanded in 2003 to in-ground trial beds, in addition to our previous raised bed trial area. New ground has already been broken for expansion of in-ground trial space for our 2004 trials.

General Information

Transplant Dates:

Raised Beds: 5/21/03.  In-Ground: 5/28 thru 6/9/03 staggered planting due to rain.  In general, 8 to 10 plants per cultivar. Spacing was varied as needed by species.

Trial Bed Locations

Raised beds are in a full sun area located between our Departmental buildings and greenhouses on the Agriculture Campus in Columbus. Current in-ground trial area is located north of our Departmental buildings. This area receives building shade until noon, and then full sun for the remainder of the day. Expanded in-ground trial beds for 2004 will be in a full sun location in a highly visible site North of our existing trial areas.

Watering and Fertilization

Watered as needed. Raised Beds are on an overhead automatic watering system. In-ground areas watered by hose and/or overhead sprinkler. Fertilization within 1 week post-transplant with Peters 20-10-20 at 200 ppm N via Dosatron. Fertilization at ~ 3 week intervals thru July.

Weather Conditions

Initial trial period was cool and wet, and plants "sat" for the first 2 - 3 weeks after transplant. This was followed by 2 weeks of oppressive heat and dry conditions. The remainder of the summer was cooler than normal with above average rainfall (based on Central Ohio conditions). These cooler, wetter conditions negatively affected the growth of certain species, such as Gazania, which prefer hotter, drier conditions.

Pest and Disease Problems

There were no noticeable pest problems. Disease pressure this year, however, was higher than normal, as a result mostly of the above mentioned weather conditions. Predominant disease problems were Pythium initially, followed by Rhizoctonia and Phytophthora. Plants were drenched with fungicide accordingly. Plants had also received a drench of PlantShield post-planting. Plants which suffered the most mortality due to susceptibility to these disease problems this year included Nemesia, Zinnia, and Bracteantha.

Evaluation Dates

Evaluations were performed on a monthly basis in July, August, and September by the Trials Coordinator. Exact evaluation dates are listed on the tables. No June evaluation was performed this year due to delayed transplant dates and initial slow plant growth due to the weather.

Evaluation Criteria

Ratings were based on a 1 - 5 scale:
1 = poor/not acceptable, 2 = fair, 3 = good, 4 = very good, 5 = excellent.

Plants were evaluated for the following characteristics:
  • Flower Number: 1 = Low, 5 = very floriferous
  • Flower Quality: Aesthetics, color, health and appearance
  • Foliage: Vegetative plant vigor, aesthetics/color, health, and appearance
  • Uniformity: 1 = Quality is variable from plant to plant, 5 = Similar quality between all plants
  • Overall: Overall rating for all plants in the grouping, taking all the above aspects into consideration.
  • Percent Survival. This data was calculated for Zinnia, Lobelia, and Gazania only. Mortality problems for other species are noted directly.

Not all criteria were evaluated each month. The most extensive evaluations were often performed in August, since that was the peak period for many entries tested.

Trial results are presented in the following groups of tables:

Individual cultivar photos can be accessed from the tables as well. Also, 'take a look at our raised bed trial area'.

The BEST of 2003: SPECIFIC CROP TRIALS

~ Gazania:  'Pink Experimental' (PanAmerican Seed), 'Gazoo Clear Orange',  'Gazoo Red w/ Ring'. Weather conditions were far from ideal for gazania here this year, a crop that prefers hot, dry conditions. These cultivars performed well in spite of it all.

~ Lobelia:  'Laguna Sky Blue'. We can't say enough good things about this one. It put on a consistent display all season, and far surpassed the other Lobelia planted next to it.

~ Zinnia: Profusion series. Still hard to beat. We trialed   'Cherry',  'Orange', and  'White' this year. These suffered less disease problems due to the cooler, wet summer than the other zinnias.

~ Annual Rudbeckia :

Best early: 'Toto Lemon'. Dwarf, compact plants. However, the Toto series was one of the first to decline sharply by mid-August.

Best mid-season:  'Autumn Colors'. Unique flower type and colors.

Best overall: 'Indian Summer'  and   'Prairie Sun'. It's no wonder they've both been AAS winners.

MISCELLANEOUS TRIALS

~ Calibrachoa: Superbells series. 'Cherry Red',   'Trailing Rose',  and   'Trailing Blue' all did well.

~ Diascia:  'Flying Colors Trailing Red'. Consistent performer all summer, and looked good next to the white Gypsophila.

~ Gypsophila:  'Festival Star'. Solid, consistent performer. It provides a welcome difference in texture and appearance as a white flower in the annual garden. Can work well alongside many different species.

~ New Guinea Impatiens . 'Infinity Orange Frost' and 'Infinity Pink Frost'. Beautiful flowers, nicely contrasting with their foliage. These were also able to maintain better than the other NGI's we tested in our trialing location which receives full sun from noon on.

~ Petunia: 'Supertunia Lemon Plume'. Unique, large lemon-colored flowers that displayed well all summer.

~ Phlox: Intensia series. ***** A five-star rating! These annual phlox were one of the best surprises of our trial season. 'Lilac Rose' performed beautifully here, and the other two Intensia series cultivars 'Lavander Glow' and 'Neon Pink' performed very well also. All bloomed profusely all summer long and were still going strong when plants were pulled in September to make way for our Fall Pansy and Viola Trial.

~ Scaevola: 'Fan Dancer'. Looked great all season. Proves that Scaevola can look good in-ground as well as in containers and hanging baskets.

~ Verbena: 'Babylon Neon Rose Improved'. Did well throughout the summer, although flower numbers were low at the last evaluation in September.

Acknowledgments: We would like to acknowledge the help of our excellent Annuals Team of Master Gardeners - Joyce Gravlee, Ken Kotch, Kathy Krantz, Mary Straney, Juliet Taylor, Bev Vogeley, and Sue Nelson. Their hard work and dedication to this project is truly appreciated. Thanks also to Annette Duetz, Learning Gardens Supervisor and David Snodgrass, Greenhouse Coordinator for their expert assistance.

And we thank the following companies for their participation in this year's trials:

Thanks also to Dr. David Tay and Susan Stieve of the Ornamental Plant Germplasm Center (OPGC), Columbus, OH ( http://hcs.osu.edu/opgc ) for their entries and assistance in planning the Annual Rudbeckia Trial.

We also thank Nancy Taylor (Wyne Ellett Plant Pest Diagnostic Clinic ) and Dr. Stephen Nameth (Department of Plant Pathology) for disease diagnosis and reccomendations.

http://plantpath.osu.edu/cweppdc/cweppdc.html