Evaluation of 48 Rose Cultivars for Low Maintenance Landscapes in Oklahoma

Abstract

Although roses have long been an important landscape plant, there is a growing interest in the use of low-maintenance roses that do not require heavy pruning or spraying. Poulsen Roser Pacific, Inc. of Central Point, Oregon, provided three plants of 48 cultivars for a trial in Stillwater, Oklahoma. The plants were produced in Oregon by grafting cultivars on seedling Rosa multiflora rootstock. Two-year-old plants were shipped bare-root to Stillwater, Oklahoma where they were planted in the field in early April, 2001. The plants were placed in three randomized complete blocks (rows) with 90 cm spacing between plants and 240 cm spacing between rows. The plants were drip irrigated as needed. During the 2002 growing season the roses were evaluated weekly for flower number, black spot, and overall quality. Four rose cultivars from Poulsen's Town and Country® series of landscape roses, Martha's Vineyard™ (`Poulans'), followed by Madison™ (`Poulrijk'), Kent™ (`Poulcov'), and Tumbling Waters™ (`Poultumb'), had the highest average flower number. Martha's Vineyard™, Kent™, and Tumbling Waters™ also rated highest among the cultivars tested for overall plant quality and black spot resistance. Other roses in the top grouping (Waller-Duncan K-ratio t test) for black spot resistance and overall quality were: Ragtime™ (`Poultieme', a climber from the Courtyard® series), Sophia Renaissance® (`Poulen002', Renaissance® series), Nashville™ (`Poulbico', Town and Country® series), Redwood™ (`Poultry', National Parks® series), Julia Renaissance® (`Poulheart', Renaissance® series), Santa Barbara™ (`Pouloesy', Town and Country® series), and Everglades™ (`Poulege', National Parks® series).