2002 OSU OSTEOSPERMUM
CULTIVAR TRIAL
~ GARDEN RESULTS ~
By By Monica Kmetz-Gonzalez and Dr. Claudio Pasian
Department of Horticulture & Crop Science, The
OSU, Columbus, OH
We have presented in a
separate report the results of our 2002 OSU Osteospermum Greenhouse
Cultivar Trial. This year, once again, we extended the trialing to the
outdoors, outplanting all cultivars in-ground to our Garden Trial Area. In
addition to the 31 cultivars screened indoors, we included the Proven
Winners' Symphony Series in this outdoor trial.
Procedure. Three plants per cultivar
were transplanted to the groundbed from 4 ‡ -inch pots on June 5. For
the Symphony series only, 8 plants per cultivar were
transplanted. Fertilization took place on June 11 and July 9 with 20-10-20 200 ppm
and 125 ppm N, respectively, via injector. Plants received `water
throughout the trial as needed via an automatic overhead watering system.
Flower number was rated by the Trial Coordinator on July 26, August 16,
October 7, and November 1. The average number of flowers per plant were
based on a 0 - 5 scale where 0 =none, 1 =
1-5, 2 =
6-10, 3 =
11-15, 4 =
16-20, and 5 =
21+ flowers per plant. At the August 16 rating, percent plant survival, plant vigor, and an overall plant rating were performed as well. The overall rating was based on general plant appearance in flowering, vegetative vigor, and overall aesthetics.
Conditions. The
growing season proved to be a test of many sorts. Planting was delayed due
to unseasonably late cold/freezing temperatures in mid-May, followed by a
few weeks of very wet conditions. This cool, wet start was followed
in mid-June through August by extremely hot, drought-like conditions.
Since the plants were stressed from the beginning, growth into August was
slow. Once the temperatures moderated in late summer, the plants rebounded
and flower numbers increased as is typical for plants requiring cooler
temperatures for flower initiation. A nice display was observed in the
garden through some light frosts. The first "hard" freeze occurred on
November 28. Plants were left in ground until mid-December for
observation.
RESULTS. The following lists information on the cultivars that exhibited the best flowering at the different rating times:
Mid-Summer: Of note,
in the heat of mid-July, the Symphony Series "everbloomers" kept
flowering. Also, Ecke Experimental #200053 had a fair number of blooms, as
did Malindi, exhibiting the potential to bloom earlier in the
heat.
Late Summer: Best
flowering and "overall" cultivars in the late August rating were Cape
Daisy 'Lusaka', Cape Daisy 'Kalanga', Experimentals # 1051-199, 99030,
1022-199, 200053, and Side Series 'Seaside'.
Fall: Best flowering
cultivars throughout October were Side Series 'Brightside', Cape Daisy
'Malindi', all Symphony Series, Experimentals #2223-1300 and #200053, Cape
Daisy 'Nasinga Cream', and Cape Daisy 'Lusaka'.
Cold Tolerance: Of
particular note in cold tolerance was Experimental #2121-1599. This
cultivar maintained new growth at the top of the plants after 3 weeks of
multiple freezes. It appeared to be the most cold hardy Osteospermum to
date here in 3 years of Garden trialing.
Rating results from July
to the beginning of November are presented in the table which is
ranked in descending order of the August 16 Overall plant
rating.
Acknowledgements.
Appreciation goes to Departmental staff members Marcia Feller and David
Snodgrass for their assistance. We would also like to acknowledge, and
give a huge thank you to our team of Master Gardeners.
Take a view of the trial: June:(Photo 1)
August:(Photo
2) October:(Photo 3)
Key to Sources of Plants:
ECKE
- Paul Ecke Ranch, Encinitas, CA
MI - Henry F. Michell Company, King of Prussia, PA
PW - Proven Winners, -Four Star Greenhouses,
Carleton, MI
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