· hydrangeas will do best if you don’t stress them by planting right before the hottest part of the year. The best time to plant hydrangeas depends on your region’s climate, but fall and spring are generally the most favorable seasons. Ensure to plant at least four weeks before the first frost to allow ample root establishment. So, when is the best time to plant hydrangeas ? “the best time to plant hydrangeas is in the fall because the conditions are less harsh than in summer, and the plant has all winter to get its roots established,” says lecompte. · yes, in fact fall is the best time to plant hydrangeas. Setting a new hydrangea into the ground at the correct time of year is the most significant factor in ensuring it develops a strong, healthy root system. · hydrangeas are a popular ornamental shrub, cherished for their large, showy clusters of blooms that provide color from summer into fall. · plant hydrangeas in the fall for optimal root growth before harsh weather sets in. When is the best time to plant hydrangeas? Make sure you wait until your last annual freeze has passed, but you still have a good 6 weeks of cool and wet weather. This shrub should have plenty of time to establish a healthy root system before the heat of summer or the extreme chill of winter, which makes the cooler shoulder seasons the best times to plant. The timing for planting hydrangeas is crucial to ensure healthy root development, optimal growth, and beautiful blooms. There are really two planting windows that give your plants the best chance to thrive—and make your life a lot easier as a lazy gardener. These plants are a favorite in landscapes, but successful establishment depends heavily on proper timing. The first is spring, usually late april to early may, once the ground has thawed.