We’ve Been Testing Hydrangea Feeds

Tested by Daniel Woodley. Fact Checked by Hannah Miller. Published to Products on the 19th August 2021. Updated: 28th February 2023.

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I’ve been growing hydrangeas for over 10 years, and I’ve found them one of the easiest plants to grow. If you give them enough water and don’t make a mistake when pruning, they should reward you with plenty of flowers and lush green foliage that will last for months, not weeks.

However, I’ve had great results by feeding my hydrangeas extra fertiliser at the right time and I’ve noticed they produce more numerous and larger blooms that last longer.

I’ll also show you my feed regimen and which products I think you should avoid.

Vitax Hydrangea Feed 1KG
Westland 20100444 Hydrangea High Performance Liquid Plant Food 1 Litre, Green
Vitax Hydrangea Feed 1KG
Westland 20100444 Hydrangea High Performance Liquid Plant Food 1 Litre, Green
Vitax Hydrangea Feed 1KG
Vitax Hydrangea Feed 1KG
Westland 20100444 Hydrangea High Performance Liquid Plant Food 1 Litre, Green
Westland 20100444 Hydrangea High Performance Liquid Plant Food 1 Litre, Green

The Best Fertiliser Ratio For Hydrangeas

NPK stands for Nitrogen, Phosphorous and Potassium, and these are the three key ingredients in any plant feed product or general fertiliser.

Nitrogen encourages overall plant growth and, in particular, leaf growth and colour.

Phosphorous helps with root growth, stem strength, flower development and fruit yield.

Potassium helps with overall plant development and strengthens the plant’s resistance to diseases and pests.

Every plant has slightly different requirements, but from my years of testing and experimenting, I’ve found that hydrangeas prefer a balanced feed or one with higher potassium levels.

For example:

My preferred hydrangea feed is Vitax, and their NPK ratio is 8-4-12, meaning this feed contains more potassium than nitrogen or phosphorous.

I’ve been using Vitax for over 4 years and have had great results.

Photos of our hydrangeas this year:

Hydrangea petals change colour rom lime-green to pinkish red
Hydrangea macrophylla mophead

Recommended Product:

Hydrangea feed

Why I Recommend Vitax:

  • Made from granules and powder.
  • I feed my hydrangeas 2-3 applications per year.
  • Perfect NPK ratio of 8-4-12.
  • Added magnesium to produce larger blooms.
  • 1kg bags with discounts for bulk buying.
  • It won’t change the colour of the flowers.
  • Won’t burn the plants as some liquid feeds do when spilt.

Alternatives

Buying different fertiliser products for each species of plant in your garden is costly and hardly practical. You can use products with similar NPK ratios so check your existing fertilisers and feeds for anything close to:

  • 8-8-8
  • 10-10-10
  • 12-12-12
  • 4-2-6
  • 8-4-12

My Experience With Blood, Fish and Bone

I always have a large tub of blood, fish and bone in my shed, and if you want to keep things simple by choosing just one or two feeds for most of your plants, I recommend starting with this but as a standalone product, I found it a little weak for my hydrangeas.

I reviewed Westland’s fish, blood and bone, which I use as my base fertiliser in my pots and flowerbeds. I found it a very cheap way to get good quality feed into the soil but I usually top up the soil with feeds specific to the species if plants I’m growing.

My Experience With Westland’s Hydrangea Liquid Feed

Westland hydrangea liquid feed is a competing product that I’ve previously used and it contains NPK at 4.5-2-7.

While effective, I found that I had to apply this feed far more frequently than Vitax’s product and even the fish, blood and bone granules, hence why I stopped using it.

I never experienced any issues with the liquid feed and the blooms were large and plentiful.

Hydrangea Feeds To Avoid

Most gardeners who grow hydrangeas do so for the large blooms, so fertilisers to avoid are those with high nitrogen content.

I’ve seen first-hand how too much nitrogen can cause plants to grow leggy, tall and big with lots of foliage, but at the expense of flower size and quantity.

From my experience, I feel that hydrangeas should be fed either a lower nitrogen feed or a balanced feed.

One product to avoid is Miracle-Gro All-Purpose fertiliser, as it contains more nitrogen than any other ingredient: 24-8-16.

How I Fed and Cared For My Hydrangeas

Here’s how I care for my hydrangea macrophylla shrubs:

Spring (after last frosts):

In spring, I usually deadhead any flowers I left on over winter for frost protection. While I wouldn’t prune off any buds, I would prune out any dead or ill-looking stems. I would then remove any leaves or debris from the shrub’s crown and rake out an inch or so of soil from under the plant and then top up with fresh compost and Vitax slow-release fertiliser.

Early Summer:

I usually top up the compost and add another dose of Vitax hydrangea feed.

Summer:

Depending on the hydrangeas appearance, I may give them a jolt of liquid feed to encourage more blooms. However, there’s no point in putting down a slow-release feed in late summer/autumn, so this is when I usually stop feeding the shrub.

Autumn:

After flowering, I would prune my macrophyllas back to a framework, I would typically take off about one-third of the stems, making sure to leave buds. If I didn’t want to reduce its size, I would leave it unpruned and just tidy it up in the spring.

A Final Point on Hydrangea Health

While the best hydrangea feed is important for plant health, I’ve found it’s not as crucial as watering.

Hydrangeas thrive in moist but not waterlogged soil, and I’ve seen them struggle in dry ground conditions.

From my experience, no amount of feed can make up for the lack of watering and dry soil.

Many gardeners claim that hydrangeas should be located in dappled or partial shade, but the truth is, they can thrive in full sun provided the soil is kept moist. If that isn’t possible, the best place for hydrangeas is a spot offering protection from the midday sun.

I’ve seen many hydrangea plants thrive without the need for extra fertilisers and feeds, but few do so if located in the wrong place and are underwatered.

Also, if you have potted hydrangeas, I suggest fertilising them at least twice a year and more often if the feed isn’t slow-release.

Photos of Our Pot Hydrangeas (Macrophylla “Ab Green Shadow”)

DIY Gardening’s Testing Process

Daniel has been growing hydrangeas in containers and his border for several years, and in 2021, he tested Vitax’s dedicated hydrangea feed.

The results in 2021 and 2022 have been excellent; the flowers plentiful, huge and colourful.

He has previously used Westland’s liquid feed with similar success. Daniel has also used Westland’s fish, blood and bone as a base feed for hydrangeas but found it was best mixed with other, slower-release fertilisers.

The products were chosen due to the high number of positive online reviews, and when testing the feeds, Daniel looked for:

  • New growth.
  • The size and colours of the blooms.
  • Leaf colour, size and health.
  • Any burning or scorching.
  • Any adverse reactions, stunted or poor growth etc.
  • Comparison to previous year’s growth.

Daniel Woodley wrote and published this review, while Hannah Miller fact-checked claims and important statements prior to publication.

Learn more about DIY Gardening’s review process here.

Author: Daniel Woodley

Daniel has over 18 years of experience in the construction, home improvement, and landscape garden industries.

He previously worked as a project manager and has experience in managing teams of tradespeople and landscape gardeners on both small and medium sized projects.

Daniel is also a keen gardener and enjoys growing unusual plants and tending to his lawn.

More About Daniel Woodley.

Daniel Woodley

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