Learn More about Hydrangea macrophylla (Bigleaf Hydrangea)

These hydrangeas are known as the ‘Blue’ flowering hydrangeas. They flower on old wood so do not trim these plants in the fall or spring. The best time to trim them is in the summer after they bloom. In Michigan, this hydrangea is not always a reliable bloomer depending on the year. The varieties that are listed as rebloomers are more likely to flower in our Michigan climate. Also, these plants will not bloom if they are over fertilized or watered and kept ‘too happy.’ These plants will grow in shade as well as sun but will have leaf wilt in full sun during the warmest part of the day so it is best to give them afternoon shade. Flower colors willrangefrom pink to blue depending on the soil ph. Fertilize them with aluminum sulfate to produce blue color flowers.