Breeding stock only

11 favorite votes.  

Bred by Peter G. Harris (United States, 1981).

Hybrid Spinosissima.  

Yellow.  Strong, old rose fragrance.  up to 25 petals.  Medium, semi-double to double, cupped bloom form.  Prolific, once-blooming spring or summer.  

Tall, arching.  Medium, glossy, dark green foliage.  

Height: 10' to 12' (305 to 365cm).  

USDA zone 4b through 9b.  Very hardy.  very vigorous.  can be grown as a shrub.  can be trained as a climber.  Disease susceptibility: disease resistant.  This rose blooms on old wood.  

Triploid

Chromosome count courtesy of David Zlesak.

This rose survives below the snow line at Morden, Manitoba, where it is bud-hardy to at least -20 F. I have been using R15-01 as a pollen parent to develop yellow roses of increased hardiness. Although R15-01 sets seed abundantly, the hips average only about 3 large, round seeds each. The seeds from open pollination (probably self-pollination) do not germinate soon or well, and few of the seedlings survive or grow well, so using the abundant and fertile pollen seems the best way to tap into the good qualities of this variety.