6 Best Blueberry Fertilizers + When To Fertilize Blueberries

Blueberries have soared in popularity in recent years and all for good reason, given their superfood status. Feeding them with the best blueberry fertilizers will make growing them a breeze, providing you get the watering and soil conditions right too.

Blueberry bushes bring interest to the garden for most of the year, beginning in Spring with delicate, white, bell-shaped flowers. Followed up with the lush green foliage that continues way beyond the heady days of summer, eventually turning red in fall. Not to mention the sweet-scented and irresistible fruit of late summer. 

These are great shrubs either for filling borders or grown in ornate containers for patios and balconies. Whatever way you plan to grow your blueberries this article will provide you with useful tips on how and when to feed these plants and I’ll be revealing the best blueberry fertilizers currently on the market.

Guide To Fertilizing Blueberries

Fertilizing blueberries in the right way will help you produce strong and healthy blueberry bushes year after year and it’s always so rewarding. Not only do they bring vibrant color and bushy foliage to your garden, but they are also delicious to eat and are loaded with health-boosting antioxidants, essential nutrients, and minerals. Gardening that is great for our immune system health? Count me it! 

Read on to check out my best blueberry fertilizers list together with top tips and know-how, along with recommendations for the best blueberry fertilizers to suit everyone’s growing needs. Whether you’ve just purchased your first blueberry bush or you’ve been growing blueberries for years, there’s everything you need to know right here. 

Soil PH for Blueberry Plants

How often and when to use blueberry fertilizer relies very heavily on the pH levels in your soil so it’s crucial you check the pH levels in your soil with a soil test kit before you start planting. So before getting started on the whys and wherefores of fertilizing, it’s worth noting the importance of acidic soil for successful blueberry bush growing. 

Acid-rich soil, that is to say, soil with a pH level of between 4.5 to 5.5 is unquestionably what blueberry plants need to thrive. These plants simply won’t grow in anything other than acidic soil. If your soil is alkaline rich and you have your heart set on growing blueberries, you’ll need to do one of two things to have a successful harvest.

You could choose to lower the pH level of the soil. This can be done by digging in sulfur chips, adding sphagnum peat to the base of the plant, or sprinkling the soil with coffee grounds well in advance of planting your blueberry bushes. This ‘top-up’ to acid levels will need to be done annually.

Alternatively, you can plant your blueberry plants in containers and buy acidic soil.  In both instances, you’ll need to make sure you are fertilizing with an acid fertilizer for blueberries.

Test the pH level of your soil with a soil testing kit both before you start growing and then annually thereafter in case you need to adjust the pH levels.

Fertilizing Blueberries

Once you have brought your blueberry bush home and have planted it in the correctly adjusted soil you should hold off fertilizing for at least four weeks. 

If you have the right soil conditions, you may not have to use blueberry fertilizer very often, if at all. Indeed, once per year in early Spring may well suffice. It’s only if your blueberry plants are not producing foliage, flowers, and fruit that you should consider boosting the amount and frequency of fertilizer. 

Too much fertilizer can cause the roots of Blueberry plants to become sensitive to salt burn. This is a consequence of their natural habitat where they originally grew in forests of Conifer trees in acidic soil.  As a result, they require very little nutrients compared to other fruit-bearing trees and bushes. 

If you do experience slow growth and a low harvest, then it’s time to provide extra nutrients to your blueberry plants. This can be done either with an organic or non-organic fertilizer.

Organic Fertilizer for Blueberries

Organic fertilizers offer a slow-release formula that delivers nutrients over a longer time period and is derived from animal or plant matter that has many nutritional advantages. They often contain a low concentration of nutrients, tend to decompose slower, and aren’t always ready to use.

Look for products with nitrogen sources such as blood meal or fish meal. Powdered seaweed and bone meal will provide all-important potassium and phosphorus. Adding Sphagnum peat or coffee grounds to the soil medium of your blueberry plants will help to provide added acidity.

Inorganic Fertilizer for Blueberries

Inorganic varieties of fertilizer typically get to work immediately. They usually smell less than organic fertilizer but they do contain chemical or synthetic ingredients.

Use products that include ammonium sulfate and potassium sulfate. These elements provide a good source of nitrogen and potassium sources.

Choosing an organic or inorganic formula comes down to personal preference based on product results and ecological opinion. Thankfully, there are many options available and also various ways of administering these products.

Fertilizer Spikes

Fertilizer spikes offer a slow-release solution that can last anything from one month to the entire growing season once they have been inserted into the soil.

Most fertilizer spikes that are available for feeding blueberry bushes are also suitable for other lime-hating plants and shrubs such as Azalea, Rhododendron, and Camellia too. 

Powder And Granular Fertilizers

There is a great range of powders and granule fertilizers available that offer a no-nonsense, slow-release solution to your blueberry fertilizer needs.

They typically need to be administered by sprinkling around the base of the blueberry plant and then gently raking in. Most get to work quickly by releasing nutrients into the soil once dissolved by water or rainfall and just like fertilizer spikes, they can last for weeks or months.

Granules and powders are a great option if you are gardening in acid soil and have a variety of acid-loving plants such as Azalea, Rhododendron, and Camellia as well as blueberry plants to feed. 

Liquid Fertilizers

Liquid fertilizers need to be diluted in water before administering to blueberry shrubs and bushes. This form of fertilizer is by far the most fast-acting because it is absorbed by the blueberry plant’s root system from the first drop of moisture. 

What I’m not keen on with liquid concentrates is how quickly they can be washed away either by heavy rainfall or by over-watering.  They do provide a sudden surge of nutrients to any blueberry bush that’s in need of a little pick-me-up.   

Feeding Blueberries N-P-K Ratio

Blueberry fertilizers typically contain nutrients that are specific to ericaceous (lime-hating) plants and are widely available.

It is fair to say that successful blueberry bush growing is more dependant on the type of nutrients contained within the fertilizer rather than the N-P-K ratio.  For example, blueberry plants do not tolerate nitrate forms of nitrogen. Instead, their nitrogen source comes from nutrients such as urea, cottonseed meal, and ammonium sulfate. These are known as ammoniacal sources of nitrogen that naturally occur in acidic soils.

Acid Fertilizer for Blueberries

Many gardeners, myself included need to rely on an acid fertilizer to give blueberry bushes the best chance of success. An acid fertilizer will help to lower soil pH to the acid-rich levels that blueberry plants need.  Look out for fertilizers that contain ammoniacal nitrogen sources such as ammonia sulfate and sulfur-coated urea.

Ammonium Sulfate for Blueberries

Ammonium sulphate is widely used in blueberry growing because it can help to maintain as well as reduce the pH of soils. Ammonium sulphate causes an acidic reaction with soil and adds nitrogen and sulphur to soil. Beware though, if you are gardening in acidic soil, repeated use can reduce soil pH below the desired range of 4.5 to 5.5.


5 Best Fertilizers For Blueberries

Whether you are lucky enough to have acidic soil that allows you to plant your blueberry bushes directly into the ground or you need to grow them in containers, we have all the insider knowledge and product facts to make choosing a blueberry fertilizer straightforward.

We’ve taken into account our own expert views as well as customer opinions to provide a comprehensive review of blueberry fertilizer to ensure you have everything you need to know in order to produce a bumper crop of blueberries year after year. 


1. Down to Earth All Natural Acid Mix Fertilizer 4-3-6

q? encoding=UTF8&ASIN=B07PL2Z7PZ&Format= SL400 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=theyardandgar 20&language=en US

If you need to lower the pH reading of your soil to get the right acid levels for blueberry growing, then this acid mix fertilizer from Down to Earth might be just what you are looking for. The added bonus with this fertilizer is you can use it for most other types of acid-loving plants too.

100% natural with an N-P-K ratio of 4-3-6, this fertilizer contains feather meal and blood meal, plus 2.5% humic acids to boost the nutrient count and acidity of soil. The packaging is even bio-degradable. So not only is it good for the environment, but it will also ensure your plants get everything they need to produce large, healthy fruit in abundance. Check Down To Earth’s the latest price here on Amazon

Down To Earth's Acid Mix 4-3-6

How to use: Lightly rake the area around your blueberry plant. Sprinkle the required amount around the dripline and lightly dig in then water the area thoroughly. Repeat this in early and late spring and after harvest.

Customer reviews: this granular fertilizer won’t just look after your blueberries, it’s great for most other types of acid-loving plants too. Users loved the versatility of this fertilizer and the company’s environmentally conscious approach.

Pros

  • 100% organic product and packaging
  • An excellent all-round berry fertilizer, arguably the best

Cons

  • Can increase acid levels in soil so check pH levels regularly

2. Espoma Holly Tone Acid Fertilizer 4-6-4

q? encoding=UTF8&ASIN=B00F2QIVQC&Format= SL450 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=theyardandgar 20&language=en US

The second pick in our best blueberry fertilizers list is Espoma Organic Holly-Tone fertilizer. This is a fast-acting formula that is suitable for lots of acid-loving plants, not just blueberries.

Espoma branded products are unique because they contain their trademark Bio-tone microbes. This leads to better-conditioned soil and healthier plant growth and all achieved with 100% natural ingredients. Find Holly-Tone here on Amazon.

How to Feed Acid-Loving Plants with Holly-Tone

How to use: Use one cup of fertilizer for every 1ft of branch spread. If your blueberry shrub is three feet or larger, double the quantity. Sprinkle the required amount around the dripline and water in thoroughly. Fertilize once in early spring and again in late spring for best results.

Customer Reviews: Holly Tone gets top marks from me and also received rave reviews from users. It gets to work straight away and results are visible within 2-3 weeks. I’ve seen struggling blueberry plants put out much healthy growth after just one application and I’ve also used it with great success as a Hydrangea fertilizer. Some reviewers found the smell a little unsavoury but hey, we are talking organic matter here and it’s a small sacrifice given the results.

Pros

  • Fast-acting fertilizer showing quick results
  • Bio-Tone formula increase microbe population
  • Suitable for use all acid-loving plants

Cons

  • Mild smell as you would expect from an Organic product

3. Dr. Earth Organic Acid Fertilizer 3-4-3

q? encoding=UTF8&ASIN=B000VZRV38&Format= SL400 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=theyardandgar 20&language=en US

This organic variety of acid fertilizer from Dr. Earth is made from 100% natural ingredients and is a great way to improve the vitality and bloom potential of acid-loving plants. Not only does it contain the basic macronutrients in a ratio of 3-4-3, but it also contains a host of other beneficial trace elements.

For a start, it boasts the inclusion of soil microbes that help to provide nutrients to the root system of your blueberry bush in a more efficient way as well as helping you achieve a bigger and better crop of blueberries. It also contains, Ecto and Endo Mycorrhizae. These are microscopic organisms found in soil that can be added to tree and shrub fertilizer to help nourish plants that may be susceptible to drought conditions.

This blueberry fertilizer is suitable for use on many other acid-loving plants but users beware, it stinks! If you can get past the smell, and let’s face it most of us can for great results and a successful harvest then this product will get to work straight away and will continue to provide nutrients for 3-4 months. 

You can buy Dr Earth on Amazon.com here.

How to use: One reason for including this in our best blueberry fertilizers list is its ease use. Simply sprinkle the required amount in and around your plants and then water it in. I love that this product represents good value for money. I have loads of acid-loving plants in my garden and a little of this goes a long way especially if you adhere to the manufacturer’s guidance.

Customer reviews: this is an effective fertilizer for blueberries but is extremely smelly. Some users reported how attracted their cats and dogs were to the smell and advised that it needs to be watered in well to avoid pets digging it up.  

Pros

  • Contains ingredients that help improve soil condition in drought conditions
  • Natural ingredients that make it kid and pet friendly

Cons

  • Pets love the smell of it. Humans, not so much!

4. Espoma Berry--tone Fruit & Berry Food 4-3-4

q? encoding=UTF8&ASIN=B07KV692TG&Format= SL450 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=theyardandgar 20&language=en US

Next up is another organic, this time from the premium quality manufacturer Espoma.  Berry-tone fruit and berry food is a slow-release formula that can be used year-round. It is suitable for feeding blueberries but can also be used as a fertilizer for strawberries, raspberries, and blackberries.

What you get with this granular-form product is Espona’s exclusive bio-tone formula that provides a steady stream of nutrients to help your blueberry bushes produce healthy-looking foliage and luscious berries that are bursting with flavor.   

I’m all about the value for money as well as the results you get from a product and this blueberry fertilizer delivers on both fronts. I find that one cupful for each mature plant is all I need for outstanding results year after year. Check Espoma’s latest price here.

How to use: Following the manufacturer’s instructions, this fertilizer can be used in early spring and then once again after harvesting your blueberries. Sprinkle ¼ to ½ cup of granules around the dripline of your blueberry bushes, lightly rake into the soil, and water in.

Customer reviews: Users saw results and were impressed when using this product on both young and established plants. As you’d expect with organic fertilizer, this is a little on the smelly side.

Pros

  • Good value for money
  • Suitable for use with most berry shrubs and bushes

Cons

  • Smelly due to the use of natural ingredients

5. Miracle-Gro Water Soluble Plant Food 18-24-16

q? encoding=UTF8&ASIN=B000VB4TSM&Format= SL400 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=theyardandgar 20&language=en US

What I love about this fertilizer from Miracle-Gro is it’s water-soluble and that is good news for fertilizing blueberries, especially young blueberry plants.  They simply don’t do well if they have been over-fertilized or if fertilizer ingredients such as sodium are allowed to build up in the soil around them.

Using this fertilizer for blueberries means you’ll quickly be rewarded with vigorous growth, luscious foliage, and a more voluminous crop. Okay, it’s not organic, so it’s not the best option if you have children or pets. Provided you are careful, it is still worthy of a place in our best fertilizer for blueberries list. Find Micarcle-Gro here on Amazon.

How to use: This gentle formula dissolves quickly and evenly in water and can be used every couple of weeks. You’ll also be able to use it for all your other acid-loving plants   You just need to dilute the required quantity with water and then use a watering can to evenly distribute around the base of your plants. Do be careful to avoid the stems and foliage of blueberry plants as they can still be susceptible to burn.

Customer reviews: it performs wells but is costly for how much you get. 

Pros

  • Fast-acting and highly effective
  • A well-known brand in the fertilizer market

Cons

  • Small packet for a premium price

6. Jobe’s Organics Soil Acidifier 30% Sulfur 0-0-0

q? encoding=UTF8&ASIN=B0063ZDQ66&Format= SL450 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=theyardandgar 20&language=en US

Finally, on our best blueberry fertilizer list is this organic fertilizer from Jobe’s. It works by using all-natural ingredients to decrease the soil’s alkalinity and can be used for lots of acid-loving plants including azaleas and hydrangeas, as well as blueberries.

I always advise clients to test their soil’s pH before applying the product. This fertilizer contains sulfur that is much-needed if you want to correct alkaline soil and adding Sulfur will help your plants produce vital proteins that are essential to an acid-loving plant’s development. Check prices here.

How to use: pour the required amount of granules into the planting hole just before planting and reapply 2-3 times per year to maintain the correct pH level in soil.

Customer Reviews: This product was awarded a 4.6/5 rating by 74% of customers who were impressed with the vibrancy of plants after use.  Users said this was their ‘go-to’ when they needed to lower the pH level of alkaline soil. The only criticism was how attractive the smell of this product was to cats and dogs.

Pros

  • Lowers soil pH to improve soil acidity
  • Outstanding vibrantly-colored fruits and blooms
  • Can use for many acid-loving plants

Cons

  • Smwll is highly attractive to cats and dogs

When To Fertilize Blueberries

To give your blueberry plants a head start, you will need to get fertilizing at the beginning of Spring just before the growing season starts. It’s important that the roots of blueberry plants have a chance to absorb nutrients before leaves have fully formed. 

For young blueberry plants or those that need a little encouragement and are lacking in growth, then administer a further dose of fertilizer 6 to 8 weeks after the first application and towards the end of spring.

Mature blueberry bushes that are planted in acidic soil are unlikely to need any further fertilizing for the remainder of the growing season. However, container-grown plants or those grown in soil with a higher pH level can be fertilized for the remainder of the growing season but no more often than every two months.  

A further dose of fertilizer should be administered after harvest as your blueberry plant moves out of the active growing season.

How To Fertilize Blueberries

It’s a good idea to loosen the soil around your blueberry plants before you start fertilizing. You can do this simply by giving the soil a gentle rake being careful not to damage roots. 

Apply fertilizer carefully to the soil around the base of the blueberry plant. Be sure to avoid any contact with the stem, branches, and foliage as this can cause burning. 

If you do accidentally get fertilizer on these areas, carefully brush it away. After fertilizing, rake gently again and give the are a watering.  

Where a layer of mulch has been applied during the inactive season you will need to temporarily remove the mulch before applying fertilizer. In my opinion, mulching should always be generously applied on top of blueberry plant soil to add nutrients and suppress weeds.

Once the fertilizer has been administered, and you have watered it in, the mulch can be put back in place on top of the blueberry plant soil. 

Final Thoughts on Fertilizing Blueberries

So there you have it. A comprehensive list of the best blueberry fertilizers available based on personal experience and a raft of customer feedback across a wide range of retail platforms and gardening forums.

Just bear in mind that choosing the right fertilizer for your blueberry bushes will depend on the pH level of soil in your garden and also the maturity of your plants.

I really hope that this review of the best fertilizer for blueberries helps you pick the right product for your needs. If you’re still unsure, consider the easy-to-apply and longer-lasting fertilizers that come in the form of non-nonsense Jobes fertilizer spikes or the Miracle-Gro water-soluble plant food. Or perhaps go for our top organic pick Dr Earth’s Acid Fertilizer, which can be used for many other acid-loving plants in your garden too.

Leave a Comment