The OSU Learning Gardens
2002 Cuphea Species Trial
Part II: New Accessions
By Monica Kmetz-Gonzˇlez and Dr. Claudio Pasian
Department of
Horticulture and Crop Science
The Ohio State University, Columbus, OH
In our previous
Ohio State 2002 Cuphea Species Trial report, we presented the evaluation
results of commercially available cultivars. This trial was part of the
OSU Learning Garden and conducted in collaboration with
the Ornamental Plant Germplasm Center (OPGC)
. This issue presents the results of our evaluation of
32 new accessions, screened for ornamental value and commercial and/or
breeding potential. Fourteen accessions were obtained as seed from the
USDA/ARS -North Central Regional Plant Introduction Station (NCRPIS),
Ames, Iowa. The remaining 18 accessions were obtained as vegetative
cuttings from the Ornamental Plant Germplasm Center (OPGC), Columbus,
Ohio.
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 14 selections were retrialed this summer in 2003, in raised beds. Some of these accessions were also included in our new Container Trials. We will present the results of this year's 2003 trial in a following issue.
BEST "NEW ACCESSION" CUPHEAS
IN 2002:
C. species - Ames
23677 . Wonderful plant!!
The best "new"
Cuphea in the trial. Flowered consistently throughout the season. Perfect
for containers and hanging baskets. Put on a consistent display (light
purple flowers), with virtually no maintenance. Appears ready for use "as
is".
C. varia - PI
607939. This was the most cold hardy of all the Cuphea in the
trial, surviving the first few hard freezes we had in November. It has
nicely contrasting flowers and foliage; delicate, soft lilac flowers
against blue-gray-green foliage. It works well in containers with its
upright /controlled habit.
C. palustris - Ames
17817. This plant worked beautifully as a vigorous "groundcover"
throughout the season. Low number of lilac/white flowers throughout main
season, with profuse flowering late season in October.
C. hybrid - Ames
22422. Nice flowers- deep rose-red petals with purple tube.
Flowering continued well into late season. "Self-layering".
C. micropetala - Ames
26109. Upright "shrub" with beautiful glossy foliage. Flowers are
tubes in shades of orange to yellow, few in number main season, but
increased in late season with the most in October.
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