Knockout roses

Question

Planted the roses in early May. They were beautiful until recently. Now 3 of the bushes have shed the blooms.

Answer 1

It sounds like the rosebushes are under some sort of stress. Lack of water and food/fertilizer can be such problems as can heat stress. Other forms of stresses would include insect attacks or attacks by funguses. Here is a link to an article that may be useful to help with your problem: https://www.gardeningknowhow.com/ornamental/flowers/roses/no-blooms-on-roses.htm