If your hybrid tea rose has stopped blooming or changed colors, a dead graft union may be the problem.
Hybrid tea and some other roses have traditionally been grafted. A bud of a beautiful rose cultivar, like Peace, Tropicana, or Lincoln, is grafted onto a hardy rootstock. This delicate union joins two different roses together. Extremely harsh weather, improper planting, or animal damage can cause the death of this union.
When the graft dies new growth arises from the rootstock. These canes are thicker with more thorns and fewer leaves. Your new plant either fails to bloom or produces flowers that are different than those produced in the past. Replace these plants with a new desirable plant.
If your rose is producing two different flowers, the graft has survived and the rootstock is producing flowering shoots. Prune off any shoots arising from the rootstock to keep your desirable rose thriving and remaining the star of the show.
A bit more information: Many hybrid tea roses are now being grown on their own roots. Northern gardeners should select well-rooted plants for quicker establishment. This will help plants get off to a good start and increase winter survival.