Small flecks and purple spots form on the leaves. This disease attacks canes while the roses are under winter protection. Brown canker may be worse on bushes hilled with soil. No chemical control is listed. Common stem canker gains entrance through a wound.
Young cankers are pale yellowish or reddish, becoming brown, sunken and cracked.
Destroy cankered canes. Black spot sprays usually prevent new infections. Dieback, cane blight canker causes leaves on the cane above the canker to wilt, turn brown and die. Destroy the cankered canes. Sprays for black spot may prevent new infections.