What causes roses not to bloom?

Reasons why roses do not bloom include excessive fertilizer, stress and improper care. Insects, such as aphids, fuller rose beetles and caterpillars, can also hurt rose bloom production by destroying the blooms or the other parts of the plant.

Roses need the proper balance of nutrients in their plant food. Fertilizers with high nitrogen levels tend to hinder bloom production in rose bushes. Exposure to extreme elements, such as heat or insect infestation, can cause too much stress on the plant, which can affect bloom production. Rose bushes that do not have enough sun or water may fail to bloom.