How to Increase Hydrangea Blooms (6 Methods)

How to increase hydrangea blooms

Do you love hydrangea flowers but wish you had more blooms that lasted for longer? I love my hydrangeas, but I noticed mine were not flowering as prolifically as others I had seen at garden open days.

Fortunately, I work at a garden nursery, so I did my research and asked some expert growers for their best tips on how to increase the number and longevity of hydrangea flowers.

I implemented the tips (with some trial and error) in this article, and my hydrangea and I can flower so. I am going to share what worked for me!

Hydrangeas bloom from early spring or mid-summer through til late summer.

To increase blooms, plant the hydrangea in the morning sun with shade in the afternoon, ensure the soil is consistently moist, and apply a well-balanced fertilizer in Spring. Hydrangeas bloom on last year’s growth, so avoid pruning your hydrangea too often to encourage more flowers. 

As there are a few factors at play, I thought I’d summarize the main points for you in this table below:

Conditions for Blooms:How to Increase Hydrangea Blooms:
Morning sun followed by afternoon shade or dappled light:Hydrangeas can flower less if they are planted in too much shade. Plant hydrangeas in the morning sun, followed by afternoon shade or dappled light throughout the day to promote flowering.
Consistently moist soil:Hydrangeas require the soil to be consistently and evenly moist for the flower buds to develop. If the soil is too dry then this can reduce flowering significantly water as often as required so that the soil is consistently moist around the hydrangeas roots.
Avoid pruning too often:Hydrangeas flower on old wood rather than new seasons growth. If you prune back the hydrangea too hard you can remove the growth from which the flowers emerge and prevent the hydrangea from flowering.
Use a well-balanced granular fertilizer:If you use fertilizer too often or in too high a concentration, then the excess nitrogen can cause the hydrangea to grow lots of foliage with fewer flowers. Use a well-balanced granular fertilizer as it releases the nutrients slowly and has all the nutrients the hydrangea requires for flowering, at the right concentration.
Ensure the hydrangea is sheltered:Hydrangeas are woodland plants and flowers for longer when they are sheltered by trees or other shrubs from frost and wind which can damage the emerging flower buds.
Amend the soil with organic matter:Hydrangeas flower more in soil that has been amended with organic matter (such as compost, leaf mold, or well-rotted manure) before planting. Mulch around your hydrangea every Spring to create the optimal soil conditions for hydrangeas to bloom.

Keep reading to learn how to increase your hydrangea flowers and how long they last, and for my personal recommendation of fertilizer for hydrangeas to support flowering…

1. Plant Hydrangeas in The Morning Sun Followed by Afternoon Shade for More Blooms

For optimal flowering, hydrangeas require a balance of sun and shade.

I consider this the most important tip: We all want spectacular flowering hydrangeas, and whilst some hydrangeas can flower in the shade, most will flower more if located in the morning sun followed by afternoon shade or when in dappled light under a tree canopy.

Early morning sun gives the plants energy for flowering and shade in the afternoon protects the sensitive leaves and flower petals from burning in the intense midday and afternoon sun.

So I recommend you find a location for hydrangea in a position where it is exposed to morning sun followed by shade in the afternoon. 4-6 hours of morning sun is optimal. 

I should caution that too much sun can scorch the leaves, and the hydrangea can also suffer from drought stress during hot times of the day, so full sun can be to the detriment of flowering; hence, the importance of balance with shade to provide relief from excess heat. (For more solutions, read my article, why is my hydrangea turning brown?)

Consider the impact of any surrounding tree canopy and whether in Summer (when deciduous trees, and in full leaf) it is providing too much shade for your hydrangea, which can decrease the number and longevity of blooms, and I recommend cutting back the canopy if necessary.

However, if your hydrangea receives dappled light throughout the day then this replicates the typical conditions of the hydrangea’s natural woodland environment and should help to promote a good display of flowers.

The most versatile hydrangea species is the Hydrangea paniculata, which I like to grow as it can adapt superbly to full sun and shade.

2. Ensure Soil is Consistently Moist for More Flowers

Are you in a hot and dry climate? If so, this point is crucial…

Hydrangeas must have soil that is evenly and consistently moist. A lack of moisture can affect new growth and, subsequently, bloom development and is most often the cause of a dying hydrangea (read my article, how to revive a dying hydrangea).

When speaking with specialist growers, they emphasized the point to me that It is particularly important to keep your hydrangea moist in the springtime when new growth is emerging.

If the soil has been prepared thoroughly before planting, i.e., with appropriate organic matter (see point 6), and there have been applications of mulch in the spring, then mature hydrangeas may not need additional watering unless there are drought-like conditions.  

We need to add mulch because mulch helps conserve the moisture in the soil; however, in hot climates and in periods of drought, soak the soil as frequently as necessary to keep an evenly and consistently moisture otherwise new bud formation can be affected.

Less mature or smaller hydrangea root systems are less extensive than more mature hydrangea, so if your hydrangea is smaller or has been planted in the last 2 years (and not fully established), then consistent watering of your hydrangea is more important to ensure a good display of flowers.

3. Avoid Pruning Hydrangeas Too Often-More Flower Buds

This is a classic mistake that I think a lot of beginner gardeners make…

One of the big mistakes in hydrangea care is over-pruning. Most hydrangeas do not require annual pruning as the flower buds develop on old wood rather than on new season’s growth. 

Hydrangeas will flower from mid to late summer and only emerge from shoots that come from last year’s growth (so don’t cut them off!) Pruning should, ideally, be limited to cutting back dead growth and flower heads. 

If you prune your hydrangea back too heavily, this tends to result in lots of lush foliage growth but without any flowers.

The only pruning that I personally do to hydrangeas is to use a pair of heavy-duty pruners to cut back dead growth back to the base. I find there are often one or two dead branches each year.

Hydrangeas are hardy, resilient plants that tend to grow stronger the following year after being pruned, but it may be a year or so before they flower again to the same extent.

If you need to prune back your hydrangea significantly, then prune straight after it has flowered. This will give as much time as possible for the plant to grow and stimulate buds for the next summer’s bloom!

However, you may have to reduce the size of the hydrangea (if it is too large for the space in your garden), in which case you should acknowledge that the hydrangea may not flower for a year or two, but with patience, hydrangea should flower well once it’s new growth has matured.

I have, on occasion, given my large hydrangea heavy pruning to tame it, and it didn’t flower the following year (as expected) but displayed lots of flowers the following year and even more the year after that!

4. Use a Well Balanced Fertilizer to Support Flower Development

I know it is tempting to apply fertilizer to give our hydrangeas the best possible chance of looking beautiful. However, I must warn you that…

Too much nitrogen, in too high a concentration (a key ingredient of fertilizer), can promote lush green foliage, but it can limit your hydrangea blooms.

The best fertilizer for hydrangeas is a well-balanced, granular fertilizer (such as Miracle-Gro).

Granular fertilizer is best for hydrangeas as it releases nutrients slowly and contains all the nutrients, at the right concentration for hydrangeas to flower.
This is the Granular fertilizer that I use. It is best for hydrangeas as it releases nutrients slowly and contains all the nutrients at the right concentration for hydrangeas to flower. I have had great results with it personally.

A granular fertilizer releases nutrients slowly and ensures the hydrangea has all the nutrients it requires at the right concentration for flowering.

If you apply mulch regularly and have properly prepared the soil before planting (with lots of compost, leaf mold, or well-rotted manure), then mature hydrangeas often do not need any fertilizer for flowering as their root system is so extensive; however, I was advised that smaller or potted hydrangeas with a less extensive root system benefit the most from the use of fertilizer in Spring.

Typically, I only apply the fertilizer once in the Spring and then again in the Summer as per the manufacturer’s instructions.

5. Shelter Hydrangeas to Protect Delicate Growth

Do you have a windy or exposed garden?

In this case, I recommend that you plant your hydrangea under a canopy or somewhere that will protect it from the wind and frost (such as by a wall, fence, or other shrubs) rather than an open windy area of the garden.

As we discussed, hydrangeas are woodland plants; they naturally grow under sheltered conditions, which reduces the risk of frost and wind damage. Try to replicate this in your garden. 

Both wind and frost can damage new growth and emerging flowers  – thus affecting blooms! 

Pro tip: I was also advised to keep the old flower heads on your hydrangea as they protect the developing flower buds from frosts during the winter. Whilst they may look unsightly, they are a natural protection from frost. 

I can confirm that leaving the spent, brown flower heads from last year really does work wonders. I had a Winter with frequent frosts and even heavy snow, and my hydrangea flower buds survived and emerged to display flowers in the Spring.

If you get frost damage on your hydrangea, then what you need to do is make sure you cut the dead off to just above the next bud down the stem.

I have observed that the buds on the outside of your plant are the most likely to be frost damaged but the flower buds further down the stem are often more protected and can still display flowers.

6. Hydrangea Flowering- Amend the Soil with Organic Matter

To get the flowers on your hydrangea looking their best, it is important to have fertile soil. Low-quality sandy or stony soil greatly impacts the quality of your hydrangea blooms.

Ideally, for the best blooms, you should prepare the planting area before planting; use lots of organic matter (compost, leaf mold, or well-rotted manure) to help provide the optimal level of soil moisture and nutrients to ensure the hydrangea has all the resources it needs to display flowers.

Hydrangeas are native to woodland environments where they grow in soil composed of leaf litter which has lots of nutrients and holds moisture well, so for your hydrangea to flowers its best, we need to replicate these growing conditions in our gardens.

If your garden soil is heavy clay or sandy, then it is even more important to prepare the soil beforehand to create the right conditions for your hydrangea to flower and thrive.

If you need to move your hydrangea into an area of more fertile soil, then I advise transplanting your hydrangea in the spring and amend the soil to a depth of 18 inches with compost leaf mold or well-rotted manure( all three retain moisture and provide soil nutrients) to accommodate the root system at full maturity.

Preparing the soil beforehand and an application of mulch in the Spring emulate the hydrangea’s natural environment and ensure your hydrangea has all the resources it needs to flower its best.

I personally add a 1 inch layer of mulch around my hydrangeas in the Spring to help conserve moisture for the Summer ahead and for the nutrients.

Pro tip: If you have just planted your hydrangea this year, then one of the best tips I have ever heard is to apply mulch in Spring after planting and then AGAIN just before Winter. Applying mulch again before the Winter insulates the soil so it is warm and allows the roots to really establish themselves in the first year. This means by the following year your hydrangeas root system will be well established in time for displaying its flowers in Spring! This has made a huge difference to my hydrangeas.

(If you are having any trouble with your hydrangeas then read my article, why is my hydrangea not flowering for the solution).

Key takeaways:

  • Hydrangeas flower more and for longer when planted in an area of morning sun followed by afternoon shade. Morning sun provides the hydrangea with energy to stimulate flowering, and afternoon shade protects the sensitive flowers and leaves from heat stress so that the flowers last longer.
  • Hydrangeas require the soil to be consistently moist, particularly in Spring, for the emerging flowers to develop. Water as often as required to ensure the soil is moist and add a layer of mulch at the of Spring to help to conserve moisture and create the optimal conditions for hydrangeas to flower.
  • Avoid pruning your hydrangea too often, as hydrangeas flower on last year’s growth. If you prune the hydrangea back too hard, you can remove the growth from which the flower buds develop the following year and prevent the hydrangea from flowering.
  • Plant hydrangeas in soil amended with compost to create the moist soil conditions that hydrangeas require for flowering. Plant the hydrangea in an area with shelter to protect the developing flower buds from wind and frost damage. Avoid pruning hydrangeas every year as they flower on old wood rather than new growth.

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