Best Fertilizers For Hydrangeas: Ratings, Reviews & Top Picks

Hydrangeas are very popular, and come in many vibrant colors including a stunning blue. Their bloom time varies as well. An interesting fact about hydrangeas is that they have flower heads so large that they can weigh down their stems because of their mass.

Hydrangeas need to receive proper fertilization to achieve optimal results. You need a good mixture of essential nutrients to promote healthy blooms, branch, and root development. The fertilizer will also boost the size, quantity, and color of the flower heads.

It’s best not to skimp on a cheap fertilizer because it could contain harsh chemicals that will ultimately hamper the growth and health of your hydrangeas. Instead, we’ll tell you how to find a quality fertilizer and tips on how to use it effectively for a beautiful bloom.

At A Glance: Top Hydrangea Fertilizers

Types of Fertilizer

There are three principal forms of hydrangea fertilizer: granule, compressed spikes, and liquid. There are benefits to using each type, so you will have to consider other factors for your final choice.

Liquid

You can purchase a liquid fertilizer that’s already ready to use, or you can get it as a concentrate to dilute with water. The benefit of liquid fertilizers is that they get absorbed quickly through the leaves and roots. That gives a solid boost of nutrition to the plants. Liquid fertilizers can spray onto the plant leaves, or you can pour the fertilizer around the base of the plant into the dirt. 

Granules

This is amongst the most popular choices for fertilizers. Granules can get sprinkled around the base of the plant, or you can dissolve them in water and pour it like a liquid fertilizer. Another option is the time-release granules. They have a polymer coating on the outside, and you have to dig and work them into the soil using a gardening tool. They take longer to dissolve, but they provide the plant with necessary nutrients over a longer period.

Spikes

The spikes are similar to the time-release granules, as they supply nutrients for the long term. This type of fertilizer has gotten condensed and takes on the shape of hardened spikes. The gardener uses these spikes by pushing them down around the soil base of the plant. For about two or three months, the spikes will dissolve slowly.

Inorganic vs. Organic Fertilizers

Most of the fertilizers that get used to feeding hydrangeas have some form of chemicals included. However, some have all-natural ingredients. Both types of fertilizers are good to make your plant healthier and to help produce robust blooms. This choice comes down to a matter of preference.

Inorganic

An inorganic fertilizer has both synthetic and chemical nutrients. It was produced inside of a lab and made to encourage specific types of growing. Perhaps it causes plentiful blooms, larger blooms, or even increased acidity. All of these are desirable growing trends when one chooses to plant hydrangeas.

Organic

If you want to steer clear of chemicals, you can buy organic fertilizers with natural ingredients like poultry manure, earthworm castings, or compost. Organic fertilizers do not contain any chemicals, but it also might not be as effective as inorganic fertilizers.

One benefit is that they could improve the health of your soil while also providing nutrients to your hydrangeas. One example is how compost helps with drainage for clay soil.

Ratio: N-P-K

You’ll notice that commercial fertilizers have labels that identify, based on weight, how much Nitrogen (N), Phosphorus (P), and Potassium (K) they contain. This formula is known as the N-P-K ratio.  

An all-purpose and balanced hydrangea fertilizer is beneficial because it has equal parts of nitrogen, phosphorus, and potassium. An example of this would be a fertilizer with a 10/10/10 N-P-K.

The balance between the nutrients gives you everything in one—gorgeous blooms and strong foliage as well. If you wanted to solely increase the size and quantity of your hydrangea blooms, then you would look for a fertilizer that’s high in phosphorus. In this case, perhaps a 10/20/10 would suit you better.

Flower Color and the pH Level

Different acidity levels produce various colored hydrangeas. White hydrangeas will only give you white flower heads. However, if you tamper with the soil’s pH level, you can get different colors.

The higher the acidity, the more likely you’ll be to get those intense blue hydrangeas that are so popular amongst gardeners. So, let’s learn a little about the pH scale for just a bit.

In this case, the pH scale lets us know how much acid is in the soil. It starts from 0 and goes up to 14. A neutral pH is 7; anything higher would be alkaline, and anything lower, acidic. The hydrangea’s color will change depending on the higher variations in the soil’s pH levels.

Neutral: This level (at or close to 7) gives you those rose pink and deeper pink shades.

Alkaline: For levels above 7, the hydrangeas will be more of a light pink color.

Somewhat acidic: If the pH level is close to 6, you’ll get hydrangeas that are purple, dark pink, or slightly red.

Very acidic: If the pH level is below 6, your hydrangeas will probably turn blue. Most gardeners prefer this color, and they will alter their soil regularly to attain blue hydrangeas.

There are a lot of hydrangea fertilizers labeled as acidic. Aside from the nutrients (N-P-K), they also have additives that change the soil’s pH. Aluminum sulfate and sulfur are the two most common types of additives used.

If you’re going for those blue flower heads, you should get a pH tester to use for your soil so that you know what you’re working with. You can use these to monitor the levels so that you can keep the soil acidic.

Top Fertilizers For Hydrangeas

Now that you understand what’s important to consider when purchasing a fertilizer for your Hydrangeas, let’s look at some of our favorite options. Depending on what soil type you have, and your planting geography, some of our picks may perform better than others.

Keep in mind, fertilizers for veggies like cucumber and pumpkin will have a different fertilizer requirement. It’s never a one-size fits all scenario. So, let’s get to it. Based on our research, here are our top picks for fertilizing Hydrangeas.

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If you want those bright or dark pink hydrangeas that will add a pop of color to your home or garden, this soil amender will get the job done. Jobe’s organic formulas are also quite popular fertilizers for Hibiscus and other flowering plants.

By maximizing the soil’s alkalinity, this fertilizer promotes better structure. The hydrangeas won’t absorb any nutrients if the pH level is below 6, and the sweet spot for hydrangeas is 6.5-6.8.

Organics Lime Fertilizer is the perfect addition to your arsenal by making your hydrangeas pink and allowing them to thrive all season.

Use the granules during planting and two to three times throughout the year for pH level maintenance. 

What We Like

• It’s easy to pour from the bag.
• You get instant results with flowering occurring in three days.
• It elevates tour soil pH level, making the hydrangeas pink.

What We Don’t

• You don’t get much product, so it won’t last long if you’re growing a lot of hydrangeas.
• It gets sold out quickly due to its popularity.

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Miracle-Gro is a granular fertilizer that acts fast to instantly boost the acidity of the soil around your hydrangeas. This is the go-to for the gardens that want big, bright, blue hydrangeas flower heads.

The Miracle-Gro fertilizer feeds your plants, adds iron, and it’s easy to use. Transform pale hydrangeas into a luminous blue color with only one application.

Use Miracle-Gro fertilizer one time a week or once every two weeks. This fertilizer works well with a sprayer or a watering can. The N-P-K ratio is 30/30/10.

Outdoor hydrangeas: Add one tablespoon of Miracle-Gro to a gallon of water.

Indoor hydrangeas: Add ½  teaspoon of Miracle-Gro to a gallon of water.

What We Like

• Makes pale flowers look vibrant again after one use.
• Fast-release granules give an instant boost.
• Easy to use and apply to soil.

What We Don’t

• The packets are small.

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Another top pick for Espoma, the Holly Tone organic fertilizer contains a special formula that works for a variety of plants. You get a whopping 18-pound bag that will last you a while.

Similar to the Miracle-Gro fertilizer, the Espoma Holly Tone formula also acts fast. You only need to apply it once a month before it rains.

Many gardeners report that it’s very easy to use, and they get consistently beautiful results time and time again. This fertilizer is a 4/3/4 ratio of N-P-K.

Get the soil prepared and add two cups of the Espoma HT18 fertilizer for every cubic foot of the soil. (Young hydrangeas)

If your hydrangeas have already gotten established, you can just sprinkle one teaspoon of the organic fertilizer into the top three inches of soil. (Outside edge of your pot)

What We Like

• Doesn’t burn or damage your plants.
• You get effective results from this fast-acting formula.
• All-natural ingredients.

What We Don’t

• The price is higher in some areas/regions.

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The Espoma Organic Bone Meal fertilizer is a 4/12/0 mix, and it gives you a small dose of nitrogen and a higher concentration of phosphorus for strong and healthy roots.

Use Espoma Bone Meal during May and also August. The earlier you do it the better, as it lends itself to create stronger blooms.

This fertilizer is available in the following sizes: 4 pounds, 10 pounds, and 24 pounds.

Use Espoma Organic Bone Meal in the Spring and also Fall seasons. You can apply one to two pounds based on the size of the shrub. You’ll need to rake the soil and water the fertilizer well.

What We Like

• All-natural ingredients.
• Encourages strong root development.
• Promotes abundant blooms.
• Low nitrogen inhibits too much leaf development.

What We Don’t

• Because this product is organic, it can attract other animals and insects easily.

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JR Peters has a prestigious and well-respected name in the gardening industry. They use an innovative approach to produce water-soluble fertilizers. Jack possesses several essential nutrients in individual packs of 1.5 lbs. The N-P-K ratio is 7/3/3.

JR Peters’ fertilizer contains just the right collection of ammonium sulfate and quality nutrients to promote optimal plant development and growth.

As the ammonium sulfate works, the micronutrients get supplied to the plant. The sulfate also helps to lower the pH of the soil to make it suitable for plants that thrive in acid.

If the product gets used as recommended, your hydrangeas will produce leaves that are lush and green, along with blue blossoms. It takes only a few weeks to begin to see your plants look healthier and fuller.

Soak the roots with the fertilizer solution. In the first month of application, it only needs to get deposited every 14 days by adding one tablespoon to a gallon of water.

In the following months, feeding your plants once each month is sufficient. The best time to apply this fertilizer is during the early morning and late evening time.

What We Like

• Develops the plant holistically.
• It lowers the pH of the soil.
• Helps to develop leaves that are fuller and greener.
• Easy to apply.

What We Don’t

• The results are inconsistent at times: vibrant blossoms may not always occur.

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This product promises to improve the strength and resilience of your plants against diseases. Moreover, it helps the appearance and color of your hydrangeas, thanks to its organic acidifier.

So how does it work? The fertilizer lessens the alkalinity in the soil with the use of all-natural ingredients. This granular formula causes plants to grow a darker green, absent of the detrimental chemicals known to burn plants.

All-natural ingredients such as sulfur correct alkaline soils. Moreover, sulfur aids in producing proteins that plants need for healthy development. Additionally, the gypsum in the fertilizer helps to develop enzymes and vitamins.

When it’s time for planting, pour the product once and reapply two to three times a year. This will allow you to maintain the desired pH level in your soil.

What We Like

• The product is easy to pour, thanks to the bag.
• Will not burn your plants.
• It works fast, and it is very effective.
• Helps turn pink hydrangeas into a beautiful blue color.

What We Don’t

• The price is higher than some other choices on the list.

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The Osmocote smart-release plant food plus fertilizer is your one-stop-shop solution for potted plants. This versatile fertilizer can be used for all plant varieties, and it works well in all growing conditions equally.

This product comes in a quantity of 8 lbs, and it can feed a plant for six months. Furthermore, the fertilizer has 11 essential nutrients that are crucial for plants.

It comes from ammonium nitrate, and it’s also a slow-release fertilizer, purposely designed to feed your plant gradually.

A standout feature of this fertilizer is that all of the granules are coated with a semi-permeable resin. Therefore, when water gets added to the plant, the special coating allows it to penetrate inside and dissolve the nutrients.

Afterward, the dissolved nutrients get released during temperature changes. Warmer temperatures are better for the nutrients to get released quickly.

Sprinkle this fertilizer into the soil, mix thoroughly, and water well after the fact.

What We Like

• Easy application
• Contains unique resin-coated granules.
• Functions well in all growing conditions.
• It is a slow-release fertilizer.

What We Don’t

• It takes longer to dissolve sometimes.

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The Flower fuel bloom booster is a very effective fertilizer from the Element brand. This fertilizer has more oil and resin, which comes together to promote a larger, heavier, and denser harvest.

You can get the fertilizer in packs of 20,000gm, 5,000gm, 1,000gm, and 200gm to fit your needs.

This fertilizer helps plants to absorb all of the organic nutrients and compounds at a much faster rate.

This complex mixture consists of vitamins, high-quality hormones, and chelating agents. Apart from this proprietary mix, there are bioavailable forms of phosphorus and potassium.

Lastly, each pack contains a 2.5 teaspoon and ¼ teaspoon scoop to ensure to give you more accuracy.

What We Like

• Promotes accelerated nutrient absorption.
• Used for all soil tops.
• Contains convenient measuring scoops.
• It has bioavailable forms of phosphorus and potassium.

What We Don’t

• It’s easy to spill the product when trying to open the package.

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Not only does this fertilizer improve the quality of your soil, but it also functions as a food source for your plants.

It comes in a six-pound bag, and it’s composed of all pure ingredients. Therefore, there won’t be any adverse side effects from harsh chemicals.

This acidifier lowers the soil to the perfect pH level for blue hydrangeas. This has all the nutrients and minerals that you’ll need to cultivate your plant. That means you don’t need to purchase another plant food supplement for the hydrangeas.

This long-term fertilizer is perfect for supplying a steady flow to your flowers. It lasts for up to two months. That means you don’t have to constantly apply fertilizer, and it won’t seep into the ground and your water supply.

What We Like

• Lowers the soil’s pH to a suitable levels.
• Contains pure organic minerals.
• Helps to achieve stellar growth.
• Long-term source of nutrients.

What We Don’t

• It could take longer to work in certain plants.

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Scotts Super Bloom is water-soluble and can get used on all outdoor plants, flower beds, and containers. This fertilizer has an N-P-K ratio of 12/55/6, and it comes in two-pound containers.

This product has a high phosphorus content that aids in achieving the perfect bloom. If you follow the directions closely, you don’t have to worry about your plants getting burned.

This fertilizer will balance the pH levels in your soil, provide your hydrangeas with the necessary nutrients, and help them to thrive in acid.

Add two teaspoons of the product to a gallon of water. Apply it around the plant base. For optimal results, feed your blooming plants every 7–14 days.

What We Like

• It’s easy to apply.
• Creates a good environment for growing.
• It promotes perfect blooms.

What We Don’t

• The fertilizer color may vary from purchase to purchase.

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Frequently Asked Questions

Final Thoughts

When you know what you’re looking for, choosing the best hydrangea fertilizers is not so hard. If you are looking for a fertilizer that checks all of the boxes, Jobe’s is highly recommended by us.

We also endorse the use of Miracle-Gro, which is designed to feed your precious hydrangeas from the leaves to the root. No matter what you need, you are sure to find exactly what you need from our list of the best fertilizers, which come highly recommended by us!