Why Is My Hydrangea Tree Not Blooming?

If you have a hydrangea that is not blooming, there are a few reasons it may be struggling. The first is that it does not get enough sunlight.

Hydrangeas need at least six hours of direct sun each day, along with a little additional afternoon shade. This is especially important for hydrangeas that are planted under trees.

Lack of Sunlight

If your hydrangea tree isn’t blooming, there’s a good chance that the problem lies in the amount of sunlight it is getting. These popular shrubs need on average 4-6 hours of morning sun per day for maximum flower production.

However, if your hydrangea is getting more than that, it may be wasting its energy on root and leaf growth, which are not needed for blooming, instead of flowering. This stress can kill your hydrangea plant, so it is important to keep the area where you have your hydrangea shaded to at least four hours each day.

Panicle hydrangeas, which include Peegee and Limelight varieties, are best for full sun, but they can tolerate partial shade as well. The other varieties, which aren’t as hardy, prefer a spot that gets about four to six hours of sun each day.

Watering Issues

Hydrangeas are water lovers that need consistent moist soil in order to grow their buds properly. If the soil is dry during the bud development process, the flowers will not emerge until the following year.

Hydrangeas can also be harmed by excessive sunlight. While some hydrangeas can handle full sun with ease, many others need to be placed in partially shaded areas for part of the day.

When plants are under stress, their focus shifts from flower production to survival. They suck up energy from the soil and leaves, limiting their ability to put out blooms.

This may be a symptom of nutrient deficiency or improper fertilization. It’s best to test the soil to see if it has enough nutrients for your plant.

Pruning Issues

If your hydrangea tree is not blooming, there are several issues that could be preventing the plant from flowering. However, the most common reason is improper pruning.

Generally, hydrangeas will only grow flowers on old wood (growth from previous seasons) or new wood (growth from the current season). Knowing which category your hydrangea falls into can help you pinpoint whether you are growing an “old wood” or “new wood” variety and what you need to do to fix it.

The most common ‘old wood’ hydrangeas include bigleaf (H. macrophylla) and oakleaf (H. quercifolia) hydrangeas and repeat-blooming varieties such as Endless Summer hydrangea.

These plants are usually quite hardy and will not fail to blossom if properly cared for. It is possible for late spring freezes to destroy tender buds before they can form, so take precautions to protect them from these chilly temperatures.

Cold Weather

The weather is an important factor in hydrangea blooms. Typically, hydrangeas do not bloom when temperatures are cold.

If a Hydrangea does not bloom in winter, it is probably because the cold weather has damaged its flower buds. This is particularly true for plants that bloom on old wood, such as mop head and big leaf hydrangeas (Hydrangea macrophylla).

While the majority of Hydrangea varieties can handle frost, there are some that will need extra protection. For these, you will need to wrap them or completely cover them.

In addition to insulating your Hydrangea’s roots, you will want to add mulch to help keep the soil moist. This can be a combination of bark mulch, pine needles, or straw. A layer of these will help the soil retain moisture and prevent fungus problems during the winter.