The OSU Learning Garden 2002 Cuphea Species Trial By Monica Kmetz-Gonzalez and Dr. Claudio Pasian Horticulture and Crop Science The Ohio State University, Columbus, OH A limited number of Cuphea types are currently available in the industry. This species trial, as part of the OSU Learning Garden, and in collaboration with the Ornamental Plant Germplasm Center (OPGC), was undertaken to identify new plants with potential ornamental value, directly for landscape use, or for incorporation into breeding programs. These accessions were tested alongside some Cuphea currently available in the market. The following is a list of sources and number of accessions trialed. OPGC, Columbus, Ohio = 19, North Central Regional Plant Introduction Station (NCRPIS)-USDA/ARS, Ames = 14, Dr. Shirley Graham - Kent State University, Kent, Ohio = 8, Industry: Possum Run Greenhouses, Timbuk Farms (Ball Floraplant), Park Seed, Select Seed = 12. Accessions were obtained in the form of vegetative cuttings, seed, or transplants, depending upon the source. There were 53 accessions, comprised of ~25 different species, representing a cross-section of flower and foliage types, plant habit, etc. CULTURE: Plants were grown in the departmental greenhouses until ready for transplant outdoors. All plants were transplanted to raised beds in the trial area on May 16, 2002. Three plants per accession were placed on 3 foot centers. Plants received watering as needed via an overhead irrigation system. Fertilization took place on June 11 with 20-10-20 @ 200 ppm N, and on July 9 with 20-10-20 @ 125 ppm N. As a note, temperatures in May after planting were unseasonably cold, followed by above average rainfall until mid-June. July and August were excessively hot (day and night temperatures) and dry. EVALUATIONS: Evaluations were performed monthly by the Annual Trial Gardens Coordinator. Plant measurements, including plant height and diameter, were also recorded at the end of June and July. To control size on some accessions, pruning, as needed, commenced in early August. The main evaluation in late August was performed by a professional core team of six individuals. Flower number, flower quality, foliage, plant habit, and overall plant quality were rated. Plants were monitored throughout the Fall. Late season flowering was evaluated on October 7, and some outstanding very late season flowering plants were noted on October 24. Plants were left in ground until early December to observe cold tolerance. RESULTS: Trial results can be located in the table . The table is arranged in order of "source". Information for each accession includes habit, plant vigor, and comments ( i.e. flower color, positive or negative attributes, breeding potential, etc.). Rating results for June, July, August and an Overall main season rating are presented as well. Ratings were based on a 1 to 5 scale (1=not acceptable, 5= exceptional). Our top 17 selections will be retrialed in 2003, in raised beds. Included will be some accessions from all sources. Some of these accessions will also be included in our new Container Trials. In this issue, we present only results of commercially available cupheas. BEST COMMERCIAL CUPHEAS IN 2002: C. ignea ‘David Verity' . Nice! A solid performer. Consistent scarlet/orange flowers are a bit larger in size and number than the typical species "cigar plant". Is taller as well; an upright shrub 2 – 3 feet tall. C. x purpurea ‘Firecracker'. Beautiful, almost fluorescent flower color-purple with deep rose-red. Flowered well all season and numbers increased in late summer to fall. Nice for hanging baskets and containers or at the edge of raised beds. C. hyssopifolia ‘Allyson'. The "Mexican heather" most commonly found in the market. This purple flowering "contained shrub" is an excellent form for borders, containers, etc. A tough, consistent performer in 3 years of trialing at Ohio State. C. hyssopifolia ‘Star White' . White flowering "Mexican Heather" exhibits star-shaped plant habit more prominently in early-mid season. It stays very contained. C. hybrid ‘Starfire' –Ames 22287. Taller "shrub"/excellent form. Pink tubular flowers all season.