Choosing between roses hot or cold is a trick question. They prefer neither extreme. Roses do best in mild temps between 60°F and 75°F (15°C to 24°C). This range lets them make food fast, open blooms with rich color, and push strong new growth on healthy canes.
I saw heat stress up close during a brutal summer stretch. Daytime temps hit 95°F (35°C) for two straight weeks. My hybrid teas stopped making buds. The ones already formed dried up and fell off. Leaves curled and turned dull. Then temps dropped to the low 80s°F (around 27°C) in early September. Within ten days those same plants pushed a wave of fresh buds. The rose temperature preference for mild weather was clear as day.
NMSU Extension backs up what I saw. Roses may stop blooming above 90°F (35°C) because heat forces buds to drop before they open. The plant stays alive but shifts energy away from flowers to cope with the stress. Leaves scorch and water needs jump. Your rose enters a survival mode that looks like decline. But it bounces back once things cool down.
Cold hits each rose type in its own way. Rugosa and Canadian roses take Zone 3 cold just fine. That means temps below -40°F (-40°C). These tough plants were bred for harsh cold and need almost no winter care. Hybrid teas are a different story. Most struggle below Zone 5 and can die back without mulch or soil mounds over their bud union. The ideal temperature for roses sits in a narrow sweet spot between these two extremes.
I tested this myself by planting the same Knock Out rose in two spots. One sits in full sun all day with no shade at all. The other gets shade from a maple tree starting at 2 PM. During our hottest July weeks, the full-sun rose stopped blooming and wilted by noon. The shaded rose kept pushing new buds and looked healthy all month. By October, the shaded plant had made 40% more flowers for the year.
Your local climate shapes which roses you should pick. Hot Zone 8 and 9 gardens do well with heat-tolerant types like Knock Out and Drift roses. Cold Zone 3 and 4 gardens need rugosa or Canadian bred roses that won't die back each winter. Zone 5 through 7 gardeners have the widest range of options since most rose types handle those mild winters and warm summers without much trouble.
If you garden in a hot climate, give your roses afternoon shade from a tall tree or the east side of a building. Increase watering to twice per week during heat waves and add a thick mulch layer to keep roots cool. In cold climates, mound 8 to 12 inches (20 to 30 cm) of soil or mulch over the bud union before the first hard freeze arrives. Remove the mound in spring once new growth starts. These simple steps help your roses handle the extremes that fall outside their comfort zone.
Read the full article: Rose Bush Care and Growing Guide
