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Why Is My Hydrangea Not Growing? (6 Common Causes)

Why Is My Hydrangea Not Growing? (6 Common Causes)

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Hydrangeas are beautiful plants commonly used in gardens as they have gorgeous flowers that come in varying colors. However, these plants can have their fair share of problems, with some of them affecting the plant’s growth. So, why are your Hydrangeas not growing?

There are a few things that can affect the growth of your Hydrangeas. These include your plant receiving too much sun or too little water, a nutrient deficiency in the plant’s soil, you may have planted your Hydrangea too early in the season, or the plant could be root bound, to name a few.

Hydrangeas are great plants to have in your garden as they offer a pop of color, but they can develop a few problems that can stop their growth. Below is a list of problems that can develop for you to use to help find the problem and how to fix it before your plant suffers permanent damage.

Why Would Hydrangeas Not Grow?

Once you have planted your beautiful Hydrangeas, and you care for them lovingly, only to notice that they aren’t growing, this can be extremely discouraging. Putting a lot of effort into your plants, only to have them not grow as you expected, can bring you down.

Unfortunately, many things can impact the growth of your Hydrangeas, which means it can be pretty difficult to find out exactly what the problem with your plant is and how to fix the issue if you can fix it at all.

Here are the main reasons why your Hydrangeas may not be growing:

  • They aren’t receiving enough water
  • They are receiving too much sun
  • There is a nutrient deficiency in the Hydrangeas soil
  • You planted your Hydrangeas too early
  • You may have pruned your Hydrangeas too much
  • Your Hydrangeas could be root bound

A lot of these issues mentioned above can cause your Hydrangeas to have stunted growth, and some could also lead to the death of your Hydrangeas if you don’t fix the problem immediately after you have noticed it. Let’s go through these issues in greater detail and see how you might fix them and possibly avoid them in the future.

1 – Not Watering Your Hydrangeas Enough

Hydrangeas might not do well if they don't get enough water

Every species of Hydrangeas are thirsty plants. These plants require a large amount of water, especially when establishing themselves in your garden or plant pot.

Not having enough water can cause your Hydrangea to have stunted growth, which is one of the most common reasons for this problem with Hydrangeas. Underwatering your Hydrangeas is easy to do as most people are unaware of how much water these plants need to thrive and grow correctly.

Hydrangeas need their soil to be consistently moist, and if yours are left to dry out between waterings, this can cause problems with your plant’s growth, and your Hydrangeas might not bloom.

If you own Hydrangeas, you need to water them based on their type and the climate you are keeping them in. For example, if you grow a bigleaf Hydrangea species and live in a dry and hot climate, you will need to water your Hydrangea every other day to ensure it doesn’t dry out.

Hydrangeas will need at least two inches of water every week to thrive in your care. So, if you keep your hydrangeas outside and don’t receive a good amount of rainfall, you will need to water your Hydrangeas more regularly.

You can use a rain gauge to help keep track of how much rain your Hydrangeas are receiving and how much you need to supplement this with your watering.

2 – Too Much Sun

Being exposed to too much sun can also cause some problems with your Hydrangeas, including stunted growth. When your Hydrangeas are kept in a location that gives them too much direct sunlight, they can stress the plant.

When your Hydrangea is stressed, the plant will begin slowing down its development as it tries to conserve energy to survive. When your Hydrangeas are in this stressed state, they will not grow and produce blooms for that season.

This is another reason it’s important to know and understand how to care for your specific type of Hydrangeas and which USDA Hardiness Zone you live in.

For example, the type of Hydrangeas known as H. macrophylla needs to be kept in part-shade conditions to survive in USDA Hardiness Zones 8 to 9, where it’s hot. However, these Hydrangeas can be kept in full sun in USDA Zones 5 to 7, as these have cooler climates.

So, you need to research your USDA Zone and the type of Hydrangeas you are growing to determine the perfect sunlight conditions for them to ensure you don’t place them in a location where they will receive too much sun.

3 – Nutrient Deficiencies in the Soil

Hydrangeas might not grow well if there are nutrient deficiencies in the soil

Like all plants, Hydrangeas need certain nutrients in specific concentrations in their soil to grow happy and healthy and not be stunted in their development. Hydrangeas can be sensitive to a lack of nutrients or too many nutrients in their soil.

The main nutrients you need to keep an eye on in your Hydrangeas soil are phosphorus and nitrogen. Nitrogen is one of the main nutrients that plants require to survive, and if there is a nitrogen deficiency in the soil, your Hydrangeas may not grow.

Phosphorus is a necessary nutrient that all plants need as this helps the plants grow new growth and roots. If your Hydrangeas soil has a phosphorus deficiency, then your plant will have a difficult time growing.

You may need to have your Hydrangeas soil tested for these nutrients to determine if they have a deficiency of these main nutrients, which may be affecting their growth. If this is the reason, you can supplement the soil with a nitrogen and phosphorus fertilizer to increase the levels.

Another thing you need to watch for in your Hydrangeas soil is the pH level. Hydrangeas prefer slightly acidic soil and do not grow well in alkaline soil. So, if your Hydrangeas are growing so slowly that you don’t notice the growth, you might need to fix the pH level in their soil.

4 – You Planted the Hydrangeas Too Early

A common reason your Hydrangeas may not be growing is that you may have planted them a bit too early in the season. As Hydrangeas require a large amount of water to establish themselves well in their new home, you should plant them in the late spring or early fall, when it’s slightly cooler.

This will help your Hydrangeas stay cool and moist, promoting healthy growth, rather than them having to fight the heat of mid-summer while trying to establish themselves.

Planting your Hydrangeas in the heat of summer can stress your plant, leading to stunted growth. You should always wait until the temperature begins to drop slightly before planting your Hydrangeas so that the plant can establish itself better in your garden.

This will help ensure your Hydrangeas have the opportunity to grow healthy and happy without battling the heat.

5 – You Pruned Your Hydrangeas Too Much

Hydrangeas might not grow if you over prune them

Pruning your Hydrangeas can be a challenging task to many people as you need to prune your Hydrangea just enough to keep it healthy and neat without trimming too much, or you could affect the plant’s growth.

This is a common reason why people seem to struggle with their Hydrangeas. If you prune your Hydrangeas in the autumn to the late spring and cut it down completely, you may be cutting away the old wood where the blooms and some new growth come from.

With certain Hydrangeas, you should never cut them down, even for the winter, as this will affect their growth. You should lightly prune your Hydrangeas in the summer after their flowers have faded.

You only need to prune off dead branches and deadhead the flowers when you prune your Hydrangeas. Ensure you do not prune off live growth unless you are going to propagate your plant.

However, if you are unsure how to prune your Hydrangeas, the best option is not to prune them at all. This will ensure your plants are healthy and growing as you won’t accidentally prune off too much, causing your plant stress leading to stunted growth.

6 – Your Hydrangeas Are Root Bound

Another aspect that may be affecting the growth of your Hydrangeas is the space they have to grow in. Hydrangeas cannot be root bound; they need a good amount of space to grow and spread their roots.

If you dig a hole in the flowerbed just big enough for your Hydrangeas root ball and plop the plant in. This can lead to your Hydrangeas becoming root bound, especially if your soil is hard or you don’t water the plant enough to keep the soil moist.

If your Hydrangeas are kept in dry conditions or the soil in your garden is harder than it should be, then the Hydrangeas may have difficulty growing out their roots and establishing themselves.

This will cause your Hydrangea’s growth to be stunted as they don’t have enough space to grow correctly. You need to fix this problem right away as this can kill your Hydrangeas.

So, if your Hydrangeas are in your garden, you need to soften the soil around the plant to allow it to grow. If your Hydrangeas are in a pot, you will need to repot them into a pot that is two sizes bigger.

Tips for Growing Hydrangeas

When you grow Hydrangeas, there are a few things you need to know about them concerning their growth. Let’s take a look at these things so you understand exactly what you can expect from your Hydrangeas growth.

Be Patient with Your Hydrangeas

Hydrangeas are plants that you need to be patient with. These plants take a long time to grow and establish themselves well in your garden after you have planted them. These plants are slow-growing, so you may not see much growth from them, especially in the first few years.

Let’s go through the first few years of Hydrangeas growth to better understand the growth you can expect from these plants.

When you first buy your Hydrangeas and plant them in your garden, you should not expect to see much growth from them, that’s if they even grow above ground at all. However, just because you can’t see any growth during this time doesn’t mean that there is no growth happening.

In the first year of having your Hydrangeas in your garden, they will be establishing themselves by growing out their roots to create a good foundation for themselves. This is why it’s important to keep them hydrated during this time.

In the second year, your Hydrangeas might grow slightly above the ground. This growth may be so subtle that you may not notice it unless you are really paying attention to your plant.

Then in the third year, your Hydrangeas will most likely take off and show tremendous growth, as it’s not established and strong. So, if your Hydrangeas are new and are not showing any noticeable growth, do not panic as this could be normal.

As long as everything your Hydrangeas need is provided, they will be fine and begin growing well. So, no matter what you do, never give up on your Hydrangeas and be patient.

Ensure You Know Your Hydrangeas Type

When you seem to have trouble with your Hydrangeas growth, you need to ensure that you know the exact type of Hydrangeas you are growing. This is because some Hydrangeas don’t grow very big to begin with, and others can grow to be huge.

So, if your Hydrangea is not growing, it might have grown as big as it will get depending on the type, which is why it won’t grow. If you want your Hydrangeas to grow big and tall, ensure you buy and plant the right Hydrangeas that will reach that height.

Beware of Harsh Winters with Hydrangeas

Some Hydrangeas are not resistant to freezing temperatures and will be affected by a hard freeze in the winter. If the temperature decreases below 41°F (5°C), this can damage the old wood of your Hydrangeas and the new growth that is beginning to develop just below the soil’s surface.

This can affect your plant’s overall growth, and it will most likely not grow much in the next growing season. So, if you know you have particularly harsh winters, then you will need to offer protection to your Hydrangeas when the cold weather hits.

Final Thoughts

Hydrangeas are stunning plants that are extremely popular for landscaping in the garden. They offer lovely bushels of flowers every year in many different colors.

However, these plants can have some trouble with their growth, and these problems need to be fixed as soon as possible to ensure the health and survival of your plant. Follow the list above to help you determine what the problem is and how you can fix it. Good luck with your Hydrangeas!