Tips & Advies
Hydrangeas close-up
6 MIN 14 Apr
Last update: 11 Apr 2023

How to Fertilise Hydrangeas: A Complete Guide

Hydrangeas provide massive bursts of beautiful multicoloured blooms. Find out how to care for them for the best results every single year.

Free download
Do you want a lawn calendar?

🌱 All important maintenance moments for your lawn during the year. Leave your email and we will send you the lawn calendar for free.

Enter your email

Receive the lawn calendar in the mail

Enjoy a green lawn all year round!

MOOWY's Choice
Choose your variation
Summer Lawn Care Kit
  Out of stock
 29.99

If you’ve ever admired a beautiful garden filled with lush, vibrant hydrangeas, you may have wondered how to achieve such impressive blooms for yourself. And we have the secret to these magnificent flowering shrubs: proper fertilisation. 

Table of contents:
Show all
  • Understanding the nutritional needs of hydrangeas
  • When to fertilise hydrangeas for maximum impact
  • How to change the colour of bigleaf hydrangeas
  • Choosing the right fertiliser for your hydrangeas
  • Expert tips on how to fertilise hydrangeas effectively
  • Common mistakes to avoid when fertilising hydrangeas
  • Additional care tips for lush, blooming hydrangeas
  • FAQs
  • Unlocking the secrets of beautiful hydrangeas

Fertilising is an essential part of caring for hydrangea plants, ensuring they receive the nutrients they need to produce those stunning blossoms we all adore. 

In this article, I’ll discuss how to fertilise hydrangeas for maximum impact, from understanding their nutritional needs to expert tips and common mistakes to avoid. 

So, let’s dive in and unlock the secret to beautiful hydrangeas!

Understanding the nutritional needs of hydrangeas

Beautiful blue hydrangeas
Beautiful blue hydrangeas – Photo by Ben Soyka on Unsplash

Before we delve into how to fertilise hydrangeas, it’s crucial to understand their nutritional needs. 

Like all living things, hydrangeas require specific nutrients to thrive, including nitrogen (N), phosphorus (P), and potassium (K). 

  • Nitrogen promotes healthy foliage growth.
  • Phosphorus encourages root development and flowering.
  • Potassium plays a vital role in the plant’s overall health, contributing to disease resistance and water regulation.

Hydrangeas also benefit from secondary nutrients and micronutrients such as calcium, magnesium, iron, and manganese. And while these nutrients are naturally present within your garden soil, they often require topping up through fertilisers to ensure your plants receive adequate amounts. 

So, understanding the nutritional needs of your hydrangeas is the first step to beautiful blooms.

When to fertilise hydrangeas for maximum impact

Timing is crucial when it comes to fertilising your hydrangeas. 

For maximum impact, fertilise your plants in early spring, just as they wake up from their winter dormancy. This will provide the nutrients needed for new growth, encouraging a healthy root system. 

And you can boost the plant’s overall health with a second fertiliser application in late spring or early summer. 

Avoid fertilising hydrangeas in late summer or fall, which will promote new growth that may not have time to harden off before winter, leaving the plant vulnerable to cold damage.

How to change the colour of bigleaf hydrangeas

Blue and pink hydrangeas
Blue and pink hydrangeas – Photo by Stephanie Klepacki on Unsplash

One of the most fascinating aspects of bigleaf hydrangeas (Hydrangea macrophylla) is their ability to change colour based on soil conditions. 

The flower colour of these hydrangeas is influenced by the soil’s pH level and the availability of aluminium. 

How to encourage blue hydrangea blooms

Acidic soils (pH below 6) with plenty of aluminium will produce blue flowers. You can lower the soil’s pH for blue flowers by adding aluminium sulfate or sulfur.

Wait until the plant shows signs of fresh spring growth. Then, mix 7g aluminium sulfate in 4.5 litres of water, and soak the surrounding soil. 

How to produce pink hydrangea blooms

You need to remove the aluminium from the soil for pink blooms, raising the pH and making the earth more alkaline. 

Decrease the aluminium availability in the soil by applying garden lime made from ground limestone. Again, the earlier in spring you do this, the better. 

For best results, grow in a pot

Keep in mind that changing the soil’s pH can take time, and it’s essential to monitor the pH levels to avoid overcorrecting. 

Lawn doctor Louis says:
If you’re determined to dictate the colour of your blooms, I recommend growing the plant in a container, making it easier to control the soil’s pH.

Choosing the right fertiliser for your hydrangeas

Applying fertiliser to the soil
Yellow patches on lawn: applying fertiliser

A slow-release, granular fertiliser with an N-P-K ratio of 10-10-10 is ideal for most hydrangeas. This will provide a balanced supply of nitrogen, phosphorus, and potassium to support healthy growth and flowering.

When trying to change the colour of bigleaf hydrangeas, choose an acidifying fertiliser for blue blooms or an alkaline fertiliser for pink flowers. These specialised fertilisers provide essential nutrients and help adjust the soil’s pH to encourage the desired colour change. 

Always follow the manufacturer’s instructions for application rates and frequency.

Expert tips on how to fertilise hydrangeas effectively

NPK chart explaining what each compound does for a plant
NPK, Garden Fertilizer Chart, Nitrogen, Phosphorous, Potassium

To fertilise hydrangeas effectively, follow these expert tips:

  • Apply the fertiliser evenly around the plant’s drip line, avoiding contact with the trunk or stems.
  • Water the fertiliser into the soil thoroughly to help it penetrate the topsoil and reach the plant’s roots.
  • Monitor your hydrangeas’ health, and adjust the fertiliser application as needed. Yellowing leaves can indicate a nutrient deficiency, while excessive growth may signal over-fertilisation.
  • Test your soil’s pH and nutrient levels periodically to ensure your hydrangeas are receiving the proper balance of nutrients.

Common mistakes to avoid when fertilising hydrangeas

When fertilising hydrangeas, avoid these common mistakes:

  • Over-fertilising: Applying too much fertiliser can lead to excessive growth, weak stems, and fewer blooms. Follow the manufacturer’s recommended application rates and adjust as needed based on your plants’ health.
  • Fertilising at the wrong time: Fertilising too late in the season can promote tender growth that is susceptible to cold damage. Stick to early spring and late spring or early summer applications for the best results.
  • Not “watering in” the fertiliser: Failing to water the fertiliser into the soil can result in a waste of nutrients and potential harm to the plant. Always water in fertilisers thoroughly to ensure they reach the hydrangeas’ roots.
Lawn doctor Louis says:
Use a hand spreader to apply granulated fertiliser. It’s the best way to ensure even distribution!

Additional care tips for lush, blooming hydrangeas

In addition to proper fertilisation, other care practices can help ensure your hydrangeas are healthy and produce stunning blooms:

  • Prune your hydrangeas at the appropriate time based on their species. Some hydrangeas bloom on old wood. On the other hand, others flower on new growth. Pruning at the wrong time can lead to a lack of blooms for the season.
  • Provide consistent moisture, especially during dry spells or hot weather. Hydrangeas prefer moist, well-draining soil and may wilt or suffer from reduced blooming if left too dry.
  • Choose a planting location with enough sunlight for your hydrangea variety. Some hydrangeas prefer full sun, while others thrive in partial shade.

FAQs

What is the best fertiliser for hydrangeas?

Hydrangeas require a balanced amount of nitrogen (N), phosphorus (P), and potassium (K). So, look for a fertiliser with an NPK ratio of 10-10-10 or other balanced proportions. Add extra aluminium sulphate for blue blooms or garden lime for pink flowers. 

Can I use coffee grounds as a fertiliser for hydrangeas?

While coffee grounds can help acidify the soil and provide some nutrients, they should not be relied upon as a primary fertiliser for hydrangeas. It’s best to use a balanced, slow-release fertiliser designed for hydrangeas to ensure they receive the necessary nutrients for healthy growth and flowering.

When is the best time to fertilise hydrangeas?

Fertilise your hydrangeas twice a year: once in early spring and again in late spring or early summer. This will provide nutrients for new growth, root development, and flowering. 

Unlocking the secrets of beautiful hydrangeas

With the proper knowledge and care, you can unlock the secret to lush, blooming hydrangeas. 

Choose the right fertiliser and apply it at the right time for your particular hydrangea variety to ensure they receive the nutrients they need to thrive. 

And if you have any questions about growing beautiful hydrangeas, don’t hesitate to get in touch!

Thanks for reading.  

Louis Hooft
Founder & Lawn expert
Introducing Louis Hooft, the founder of MOOWY and your reliable expert. With a profound love for stunning lawns and extensive experience in garden maintenance, Louis is here to assist garden enthusiasts in achieving a greener and livelier outdoors than ever before. Count on Louis for invaluable tips, clever tricks, and top-notch products to make your garden flourish!
back
SURVEY
Find the best match for your needs in no time!
Answer 2 questions and we provide you with the best product.
SURVEY
We help you to choose your best product
Question 1/2
Loading your result…
  • What is your lawn care goal?
    1. A. Greener grass
    2. B. A more lush, dense lawn
    3. C. Bald spot repair
    4. D. Lawn restoration
    5. E. Laying out a new lawn
    6. F. Combating moss
  • For which season?
    1. A. Spring
    2. B. Summer
    3. C. Autumn
    4. D. Winter
  • Describe your lawn:
    1. A. My lawn has shaded areas
    2. B. My lawn is used intensively (e.g. by children & pets)
    3. C. I have a decorative lawn
    4. D. I have a standard lawn without special features
  • How many bald spots do you have?
    1. A. A lot, my lawn looks like a barren wasteland
    2. B. A few bald spots here and there
  • Describe your lawn restoration goal:
    1. A. I want to completely renovate my lawn
    2. B. I want to overseed my existing lawn
  • Describe your lawn:
    1. A. My lawn is shaded
    2. B. My lawn will be used intensively (e.g. by children & pets)
    3. C. I would like to have a decorative lawn
    4. D. I would like to have a thick and strong lawn
  • How bad is the moss problem in your garden?
    1. A. Bad. My lawn is covered in moss.
    2. B. Just a few spots
RESULT
Here’s the product that suits your goal best
Try this one.
< Try again

Comments (0)

There are no comments yet. Well then, what are you waiting for to
inaugurate this pretty page?

Be the first to write your comment!
+ Load more
comments

Do you have some comments?

OUR TOP

+Best sellers

Our most popular products

Browse Best Sellers
Choose your variation
Front image of Scarifying Kit
Scarifying Kit
  In stock
 37.99
Choose your variation
Front image of Spring Lawn Care Kit
Spring Lawn Care Kit
  In stock
 24.99
Top
Choose your variation
Front image of the Long Lasting Lawn Fertiliser lawn feed product pouch with lawn feed in front of the pouch
Long Lasting Lawn Fertiliser
  In stock
 12.99

– WHO ARE WE –
We believe that everybody should enjoy a green, healthy garden. Effortlessly.
Free download
Do you want a lawn calendar?

🌱 All important maintenance moments for your lawn during the year. Leave your email and we will send you the lawn calendar for free.

Enter your email

Receive the lawn calendar in the mail

Enjoy a green lawn all year round!