8 Reasons Why Your Hydrangea Is Not Blooming

Hydrangea foliage
Hydrangea foliage

DigiPub / Getty Images

When the hydrangea you planted in your yard does not bloom at the same time as your neighbor’s, this is not necessarily a reason to worry—there are many different types of hydrangeas, and they don’t all bloom at the same time.

To find out what, if anything, is wrong with your hydrangea, determine first which type of hydrangea you have. The most common types grown in North America are:

  • Bigleaf hydrangea (Hydrangea macrophylla), which includes the mophead hydrangea, lacecap hydrangea, and mountain hydrangea (Hydrangea serrata)
  • Panicle hydrangea (Hydrangea paniculata)
  • Smooth hydrangea (Hydrangea arborescens)
  • Oakleaf hydrangea (Hydrangea quercifolia)
  • Climbing hydrangea (Hydrangea petiolaris)

Another determinator of hydrangea bloom time is the local climate. In the South, an oakleaf hydrangea flowers in early summer while in a cooler location in the Midwest or northeast of the US, it won’t start blooming until the late summer.

If your hydrangea is indeed not blooming, the checklist below helps you to determine what the issue is and how to fix it.

1. Potted Gift Hydrangeas Usually Don’t Rebloom

Transplanting hydrangeas that are sold as gifts for Easter or Mother’s Day in small pots, often wrapped in a decorative foil, usually have a low chance of survival, let alone blooming. They have been conditioned with lots of fertilizer to bloom for a short time and often it’s a variety not hardy for your area.

2. Hydrangea Is Not Hardy for Your Climate

My image shows 'Nikko Blue' hydrangea. This bush has blue flowers.
'Nikko Blue' hydrangea is a "big-leaf" type David Beaulieu

Hydrangeas vary in their hardiness, with bigleaf hydrangeas being the least hardy and panicle hydrangea being the hardiest. If a hydrangea does not bloom, it could be that it is not suitable for your climate zone. While the root system might survive the winter, the buds are killed by extreme cold, hence no bloom the following year.

3. Late Frost

If the hydrangea is suitable for your climate zone, a strong, unseasonably late frost or strong cold winds can kill or stunt the flower buds and result in a summer without a bloom.

Keep an eye on the weather forecast in the spring and, when frost is in the forecast, cover the hydrangea entirely with burlap for the night. Remove the burlap promptly again the next morning and repeat as needed. Don’t leave the burlap on the plant all the time as you would for winter protection.

4. Inadequate or Too Much Sunlight

Hydrangea likes partial shade
Hydrangea likes partial shade mtreasure / Getty Images

To bloom, most hydrangeas require at least three to four hours of sunlight, ideally in the early morning, or dappled shade. Locations with full afternoon sun are usually too intense. Both too little and too much sunlight can affect the bloom. The variety that can tolerate the most sun exposure is the panicle hydrangea.

5. Timing of Pruning

Hydrangea pruning
Hydrangea pruning Valeriy_G / Getty Images

How and when you prune a hydrangea is crucial for blooming. And, again, it all depends on the type of hydrangea. Some bloom on old wood, others on new wood or on both old and new wood. Without knowing which hydrangea you are pruning, you risk removing the growth that will produce flowers. And make sure to follow the instructions for pruning hydrangeas.

6. High-Nitrogen Fertilizer

When hydrangeas are given fertilizer with a high nitrogen content, they produce mainly foliage and no flowers. What they need is a fertilizer that is high in phosphorus (P), as it boosts the growth of roots and shoots on which blossoms develop. This type of fertilizer is often labeled as a bloom booster and it should be applied in the early spring and again in mid-summer.

Hydrangeas do best in soil with a low pH. You can use a fertilizer for acid-loving plants but keep in mind that it might have a higher nitrogen content.

7. Lack of Moisture

Next year’s flower buds form during the summer. If your hydrangea does not bloom, it could be that it was watered insufficiently or under drought stress the summer before. Try to think back to last summer to determine if that is the cause.

To prevent this from happening again, make sure the soil is continuously moist but well-drained.

8. Newly Planted Hydrangea

It can take a hydrangea a couple of years to get fully established. If you give it all the necessary care and none of the above issues apply, it might just take time and patience to see it bloom.