Roses

Roses were some of the earliest woody landscape plant cultivars released from the U of M, and a sideline of the chrysanthemum breeding project in the 1940s. Two varieties from that program are still widely available. The popular climber, 'Viking Queen,' quickly covers walls, trellises, or fences with a bounty of medium-pink, fully double blooms produced in clusters with a look of English roses. Very fragrant, and disease resistant, it blooms from June to frost. 'Prairie Fire' is a durable shrub rose with single red blooms.

The rose breeding program was reinitiated in 1990 with the goal of developing larger, disease-resistant, hardier shrub roses on their own roots. From many thousands of rose seedlings produced, 200 plants were selected as future parents, and 12 are in national trials. Serendipitously, researchers spotted a polyantha rose at the Minnesota Landscape Arboretum that led to new selections expected to be retailed in the near future.

Only at the U

Hardy polyantha roses, with their small stature, constant bloom, and large clusters of small flowers, will soon be added to northern landscapes. Several selections are scheduled for release in 2007.

Twelve selections of hybrid shrub roses are being evaluated for floral quality, rebloom, hardiness, blackspot tolerance, plant size, and habit. The best will be commercially available in several years.

Black spot fungus has challenged gardeners for centuries. Using black spot isolates collected from across eastern North America, University scientists can characterize the molecular diversity of the fungus. Rose genotypes will be inoculated with black spot isolates to determine the race diversity of the isolates. Breeders can then identify black spot resistance genes in rose germplasm and begin the process of incorporating those genes into cold-hardy shrub roses.