Question and Answer: Why isn’t My Hydrangea Blooming?
By: Lauren M. Liff for Dabah Landscape Designs
Hydrangeas are one of the most popular flowering shrubs used in a typical New Jersey landscape due to their beautiful color variations, attractive foliage and of course their unique flower heads. However, one of the most frequently asked questions when it comes to these plants is: “why isn’t my hydrangea blooming?” The reason behind whether or not your hydrangea is blooming depends on what variety you have as some of them will grow flowers on old growth, where others will grow their flowers on new growth. Let’s get to the bottom of this dilemma so you won’t have to ask: “why isn’t my hydrangea blooming?” anymore!
There are six common types of hydrangeas commonly seen in North American gardens: Bigleaf, Panicle, Smooth, Climbing, Mountain and Oakleaf. It’s always important to know if the variety of hydrangea that you have blooms on new wood or on old wood – knowing this detail effects when to prune your hydrangea. Incorrect pruning habits are one of the main reasons behind hydrangeas not blooming.
The Bigleaf hydrangea seems to be not only the most commonly purchased hydrangea but also the one that seems to raise the most concerns when it comes to blooming.This species is a little confusing because it creates a lot of cultivars that can die back to the ground especially when there is a harsh winter – since they bloom on old wood, you can see how this might cause a problem. However, it is also possible that you’ve selected a variety that doesn’t do particularly well in your zone. You can help your hydrangea by protecting it in the winter, for example by mulching around the base of the plant to cover the root zone.
Another reason as to why your hydrangea won’t bloom is the possibility that you pruned it too far back the year before. If hydrangeas are over pruned in the summer they will die back farther than they usually would leading to a skipped year of blooming. The safest way to avoid this issue is by only pruning your hydrangea in early spring – that way it is easy to differentiate between old wood and new wood. You should pay attention to what kind of hydrangea it is and how far back it died the previous year, that way you will know what and how much to prune back.
Over fertilization can also cause hydrangeas not to bloom. You can take a soil sample for testing to find out when you fertilized last and what levels of nutrients are in the soil. The soil having too much nitrogen or not enough phosphorus could cause the hydrangeas not to bloom. Nitrogen is the nutrient responsible for lush green growth; too much nitrogen means a very thick green plant with little to no blooms. Phosphorus aids in the fruiting and flowering of the plant, therefore the less phosphorus there is in the soil, the less blooms you will have. You can help correct this by adding a phosphorus-rich fertilizer or bone meal to the soil.
Hydrangea blossoms are incredibly showy and beautiful to say the least. So when your hydrangea isn’t blooming it is quite easy to notice. Even though this is a very common concern among hydrangea admirers, it is a solvable problem. By following the suggestions that we have mentioned in this article you can aid your hydrangea in staying happy and healthy and pushing out those absolutely stunning flowers.