It is April and unusually hot weather has resulted in roses with leaves open along stems. Because there may be frosts yet to come , do I wait to prune roses until late May.
Weather conditions and the stages of a rose’s development, not the date on the calendar, should determine when you prune your roses. Generally roses are pruned at the end of the dormant season, as the buds begin to swell and before vigorous new growth begins. In some years that would be a description of a roses annual development in late May in Toronto. However this year, we have had unseasonably warm weather, and the green growth is bursting out all around us, it is not too early to prune your roses. Before taking up your secateurs, I suggest you check the weather forecast, to see if a late hard frost is predicted. If you prune now, and there is a late frost, the newly growing tips might be damaged and, . if that happens, you might have to prune again, to get rid of the frost damaged shoots.
Here is a link to a Garden Guide prepared by Toronto Master Gardeners on Pruning Roses, which you might find helpful:
April 21, 2023