Roses do not all bloom in the same month. In fact, numerous factors such as type of rose, location and weather all have important bearings on when roses bloom. Most roses will bloom in the spring, but some varieties, such as climbing roses and bushes will not bloom until the summertime. Of course, roses will bloom earlier in warm climates such as the South.
Roses growing in very warm locations, such as South Florida will bloom year-round. However, most of the country doesn't have warm months in the winter. In a place like Minnesota, most one-time bloom roses like Species roses and Old Garden roses will bloom most heavily in June, according to the University of Minnesota. In the Pacific Northwest, the bloom date depends on the amount of sunshine the roses get. They can begin growing anytime from late May to mid June.
Some roses are considered repeat bloomers. This means they may bloom once in May or June and then bloom again in the fall months like September. The spring flowers bloom on the new canes that grew on the wood the previous year and then the autumn blooms on the new summer canes. Some roses are considered continuous bloomers that will continue to bloom throughout the spring, summer and autumn before going dormant in the fall.
In order to properly bloom, roses like at least six hours of full sunlight per day. In places like the Pacific Northwest, cloudy conditions may persist until June, delaying the beginning of rose blooming season. It is important the roses get full morning sun since it will dry moisture that can lead to fungal disease. If you plant your roses in a place where there is shade, it is likely they will not bloom at all or they will become leggy and more susceptible to disease.
Moisture is also important if you want your roses to bloom on the time or at all. They require at least 1 inch of water per week and up to 2 inches per week during the growing season. In the summer, you should water every four to seven days, more if the summer is particularly hot. Do not get the leaves wet during the day since this is an invitation to fungal infection.