Last Updated on March 4, 2022 by Grow with Bovees
Why are my hydrangeas not blooming?
It is a common question, and there are several possible reasons why this could be.
Hydrangea varieties are stunning flowering plants native to a few different regions and countries.
These include; the Himalayan mountains, Indonesia, Asia, Japan, and the Americas.
Their flamboyant, fragrant and very pretty blooms growing from flower buds make them a popular choice in all sizes of gardens.
You have now gone through so much effort to choose a variety which is known for blooming starting in spring and blooming right through summer and even in early autumn and after doing everything, your shrub is still not blooming.
It is understandable that you want answers to the question of why won’t my hydrangea bloom.
The name hydrangea is a combination of two Greek words, “hydro” meaning water and “angos”, a direct reference to their cup-shaped seed pods but double apt as they are renowned for guzzling water.
This immediately offers a clue as to one possible answer when people ask why their hydrangeas won’t bloom; insufficient water!
There are however a few other possible reasons to consider when noticing that the hydrangea won’t flower. There are also different reasons for different types of hydrangea.
Therefore, it is important that we help you identify which type of hydrangea you have selected.
Types of Hydrangeas
There are about 200+ species of Hydrangeas available, of which four are noteworthy types that grow in American gardens.
Bigleaf Hydrangeas (Hydrangea Macrophylla)
Due to the fact that the blooms are regularly used as cut flowers, the “big-leaf” type hydrangeas are often referred to as Florist’s Hydrangeas.
Hortensia and French Hydrangeas, are the most common type of hydrangeas, and are available in three different types, mountain hydrangea, mophead hydrangea and lacecap hydrangea.
This species is distinct for its large flower heads that are typically available in three beautiful colors; blue, purple, and pink flowers.
The color of these can be confusing, as the hydrangea blooms will be blue, or pink blooms, depending upon the soil conditions that they are planted in.
Smooth Hydrangea (Hydrangea Arborescens)
Hydrangea Arborescens is available in several varieties, and is noted for its beautiful flowers that appear first as tiny lime-green globes opening up into a round head of beautiful creamy white flowers marked off by lovely lush dark green leaves.
These spectacular flowers can grow as big as 10-inches and are often planted as hedges in colder climates as they withstand low temperatures very well.
Oakleaf Hydrangea Flowers (Hydrangea Quercifolia)
Not surprisingly, named after the shape of its leaves, Hydrangea Quercifolia is another hardy type of hydrangea suitable for colder temperatures and can be grown in sun or shade in moist soil.
They feature cone-shaped clusters of white flowers that, in most cases, fade to pink, and then to tan.
They are also the only kind of Hydrangea with the ability to change their leaves color in the autumn, going from yellow through orange to a gorgeous deep red.
Climbing Hydrangea (Hydrangea Petiolaris)
Native to America, these hydrangeas are actually classified as vines, having the ability to climb up against walls, trees and also trail along floors.
Their flower heads are flattish with fragrant white flowers on the outer edges and smaller budlike flowers in the center and can grow up to 5 inches in diameter.
In autumn, the hydrangeas bloom turns a reddish-brown color and are used effectively in dried flower arrangements.
The textural peeling bark also offers an added attraction in winter.
A good thing to remember about this hydrangea variety is that it blooms a bit later in the season in comparison to other hydrangea varieties.
Don’t get impatient while waiting for it to develop flowers, it likes taking its time to begin with.
Other shrubs include the mophead hydrangea, the lacecap hydrangea and the panicle hydrangea.
Reasons Why Hydrangeas Are Not Blooming
So now that you’ve had a bit of background to help identify your hydrangeas blooming habits and whether they grow on old wood or new wood, let’s look at the reasons why endless summer hydrangeas or the big leaf hydrangea for example won’t bloom and in particular why YOUR hydrangea doesn’t bloom.
Pruning at the wrong time of year or incorrect pruning is a trap that many hydrangea growers fall into and if you get it wrong then quite literally your hydrangea won’t bloom.
Early flowering hydrangea most commonly bloom on old wood, and they set their flower buds in the Northern Hemisphere at the start of August and onwards, becoming ready for flowering the following spring thereafter.
If you prune them after August, you will very likely have no, or only a few flowers the following year.
Late flowering varieties flower on new wood which starts shooting in the spring, so it is best to prune just before they start blooming in late winter/early spring.
There are a select few varieties which are ‘remontant’ meaning they will reform flower buds on a stem where the first buds have been incorrectly pruned, or perished due to early frost.
The reason they are able to do this is that they bloom on old wood and on new wood.
The plant tag on the shrub you choose will inform you whether they bloom on old wood or new wood.
Check which variety you have before you stunt your plants blooming due to improper pruning.
N.B. Dead heading does not count as pruning.
Deadheading enables the plant to save energy it would otherwise have used for making seeds, and enables it to then use that energy for invigorating root and shoot growth ready for producing more plant blooms.
If there is a freezing winter, and you have a variety that is not very hardy, then frost/freezing conditions could wipe out all of your blooms for the following spring.
Depending on the size of your bush and your dedication, this can be avoided by keeping an eye on the weather forecast and if they are planted in the ground, you might want to wrap the flower buds in a frost blanket for plants, burlap wrap or a similar material (not plastic as they need to be able to breathe) to protect them from extreme cold.
If you are growing your hydrangea in a pot, relocate them to a greenhouse/shed/garage until the worst of the winter is over.
Check your plant hardiness.
Be careful of late spring freeze, which might be common in your zone. Too cold temperatures due to late spring frost may stunt or even kill the flower buds and this in turn results in no flower development in summer.
Some varieties of this shrub may be sensitive to wind during the harsh winter months. These should be protected from cold, frosty breezes.
Location of The Hydrangea Tree
If you have never seen your hydrangea bloom, then it could well be that it was planted in the wrong location with incorrect lighting conditions, soil type or weather conditions and may never have bloomed.
Has The Hydrangea Flowered in the Past?
If your hydrangeas aren’t blooming but have previously flowered beautifully then it is worth checking if something has changed in its immediate surroundings.
Has a tall fence or wall been built that is now creating an area of too much shade?
Likewise, has a wall or building been knocked down, causing your new hydrangea buds to be shrivelled by the scorching sun.
Changes to the landscape may also affect and change the drainage, water supply and condition of the soil.
Animals moving around the area and feeding on the lovely soft new buds is also often a reason why you think your hydrangea won’t bloom, when in fact it had started to do so.
Check for tracks and newly nibbled stems.
Hydrangea Fertilization Problems
As we have indicated above, there are various reasons as to why a hydrangea doesn’t bloom but one of them is NOT due to UNDER fertilization.
If the problem is caused by some type of fertilizer, then it is far more likely to be the application of too much fertilizer. Lots of fertilizer can dry out the roots, causing severe damage or even resulting in death.
Fertilizing at the wrong time of year may also be a reason why your hydrangeas are struggling to bloom.
If hydrangea fertilizer is applied too close to the start of the plant preparing to go dormant, then it could cause the plant to send out new shoots too early which then succumb to winter frosts.
Giving your hydrangea a high-nitrogen fertilizer, will promote the new growth of healthy leaves rather than healthy flowers.
Consider using a time-release fertilizer that has a high content of phosphorus. This kind of fertilizer is beneficial to the hydrangea flowering.
These types of fertilizers are commonly known as bloom boosters in garden centers and the ideal time to feed them to your shrubs would be during early spring followed by more in mid-summer.
Unlike many other plants, hydrangeas are acid loving plants, keep the soil pH acid.
Check the ideal fertilizing strategy for your particular variety and remember not to fertilize directly around the base of the plant, but rather around the drip line.
Lack Of Moisture
Moisture is also an important aspect to remember when wanting beautiful flowers. Enough moisture is especially important during the first two years of a newly planted hydrangea.
Plant them in a well-draining potting soil and be careful not to let the soil dry out completely. Daily watering will be required in summer to keep the soil moist.
Hydrangeas are not fond of dry conditions. Adding a layer of mulch to your soil, will aid it in holding onto moisture.
The hydrangea paniculata is a variety that is most likely to survive and even grow well in dry conditions and can therefore be successfully grown in a cooler location.
Amounts Of Sunlight
Too much shade or too much sun is not good for your hydrangea, and it may cause stunted growth.
Don’t get us wrong, they thrive well in areas of partial shade, but they are also in need of about four hours of dappled sun in the afternoon or even direct morning sun a day.
So, if you feel the spot where you placed your shrub is too dark, move it to a space or spots of more sun which consists of bright but indirect light. These would make for convenient locations with enough sun.
Direct afternoon sun or full sun during the later parts of the day is often too intense for the hydrangea to handle, which in turn will negatively affect the blooming of the hydrangea.
Note that the panicle hydrangea is quite tough and is able to survive quite a bit of sun exposure.
Gifted Hydrangea Bloom
Gifted hydrangeas that have been planted in small pots and prepared for special occasions such as Mother’s Day or Easter, do not commonly survive when being replanted. If you do receive such a plant, it is best to immediately transplant the hydrangea to a larger pot, and keep it properly watered and away from cold and drafts.
Blooming is, therefore, also very rare. This is due to them being forced into early bloom by the application of fertilizer overload.
Different hydrangeas grow in different zones.
You should thus get a variety that is able to bloom in your zone. If one species does not thrive in your climate, try to get a different one.
Newly Planted Hydrangea Plants
The first or second year of the hydrangeas’ life is often focused on developing root systems in order to keep them strong and healthy.
Blooming is therefore unlikely to happen during that time. Give it some time and don’t expect flowers within the first year or two after planting your hydrangea.
There you have it, fellow plant lover.
When growing hydrangeas, it is important to remember that different varieties bloom at different times in their life.
Most hydrangeas are not cold hardy and are therefore not fond of cold conditions — be aware of late spring frost — and they also like to be kept in locations of partial shade.
All the above information needs to be taken into account when wanting to promote the new growth of healthy blooms.
Follow this advice and you’ll make your hydrangea bloom in early summer and maintain blooms all summer long.
Try out different varieties of this shrub in order to figure out which one fits best for you, your climate and your location.
May it be the hydrangea macrophylla, the Hydrangea paniculata, the hydrangea arborescens, the hydrangea quercifolia, the oakleaf hydrangea, the hydrangea serrata, a big leaf hydrangea or an endless summer hydrangea.
They are all equally beautiful, coming with flowers in shades of pink, to deep purple and blue.
And with a little help from mother nature, we are sure that you will be able to successfully grow at least one of the above named species and keep these hydrangeas blooming.