The majority of trial plants for the Michigan State University (MSU) field trials were started from seeds that were sown between March and April. Perennial flower seeds were started as early as January 18. Seeds were germinated in seed flats or plug trays in a greenhouse set at 75°F daytime/nightime. After appropriate growth, seedlings were transplanted to 4-inch containers or 1204 flats.
Cloned plants were propagated by cuttings or tissue culture in commercial greenhouses. Rooted cuttings were shipped to MSU as plugs. Upon receipt, the rooted cuttings were transplanted immediately into 1801 flats. Most were received and transplanted between late March and mid April. Unrooted cuttings were stuck into flats of a peat-lite soil mix and grown in a mist-house until roots emerged.
After transplanting, all seed and vegetative material were grown in glass greenhouses set at ~75°F daytime and ~68°F nighttime temperatures until moved to the garden beds. Plants were grown in peat-lite soil mix (2-B Mix generously donated by Fafard) and fertigated at every watering with 19-4-23 (125 ppm nitrogen) water soluble fertilizer. No plant growth regulators were used on annuals evaluated in these trials.
Companies are given the choice of whether they would prefer their plants to be grown in containers, hanging baskets, or ground beds. When requested, plants were transplanted into 22-inch containers or hanging baskets and held in the greenhouse for about two weeks before placing them outdoors between May 23 and May 27. Depending on the size of the transplant, containers/hanging baskets were planted with 7 (1801-size) to 10 (1204-size) plants.
Outdoor Ground Bed Management
Fall 2015 – Cleanup, early bed preparation
After removal of annuals in the fall, all beds were raked and cleaned. Compost was added to all beds each fall. In 2015, MSU did not add compost due to soil test results revealing a very high (22% to 26%) organic matter content and optimal to supra-optimal N (nitrogen), P (phosphorus), and K (potassium) levels in the soils.
Spring 2016 – Pre-planting activities
Bed lines were marked and sprayed with Round-Up. All beds lines were hand cut. Round-Up was applied where necessary to control weeds before planting.
Spring 2016 – Planting Schedule
The majority of transplants were planted outdoors between May 31 and June 6.
Typical plant spacing
Plants are typically planted at 8 inches to 12 inches on center, depending on the species. MSU typically plants at least 24 plants per trial entry in landscaped beds. Due to space restraints, fewer plants were used for vegetable trials.
All beds and containers were hand watered as needed. Due to hot conditions and drought during June and part of July, beds and containers were sometimes watered on a daily basis.
Ground beds were fertigated every two to three weeks with a 19-4-23 (250 ppm N) water soluble fertilizer starting mid-summer. Petunia and calibrachoa varieties were treated approximately every two weeks with Jack’s Petunia FEed, a high-acid fertilizer, used to combat the effects of increasing media pH during the growing season.
All beds were hand weeded and cultivated as needed until plants filled in. With the hot weather this summer, the garden staff and volunteers both acknowledge that the weeds have been particularly aggressive, purslane in particular. Long hours of hand weeding were required to keep the beds looking good. Volunteers helped a great deal with this tedious task.
Insect and Disease Control
No treatments were given this year for insect or disease control in the annual gardens. Other than typical damage from Japanese beetles, relatively few troublesome insects or diseases were noted this year thus far.
Begonia ‘Jurassic Red Splash’
Begonia Solenia Series
Ipomoea ‘FloraMia Rosso’
Calibrachoa ‘Superbells Coralina’
Calibrachoa ‘MiniFamous Neo Yellow+Red Vein’
Coleus ‘Main Street River Walk’
Confetti Trio Garden Mix Main Street Times Square
Confetti Trio Garden Mix Main Street Trafalgar Square
MixMasters Feelin’ Lucky
MixMasters Lucky Charm
Petunia ‘Surfinia Trailing Deep Red’
Petunia ‘Surfinia Sumo Pink’