Hydrangeas are some of the most beautiful and popular garden flowers. When grown well, they are bright, dense, and look incredible in any green space. They are also very easy to grow! What’s not to love?
Although, that isn’t to say that growing hydrangeas always runs smoothly. In fact, they often need a good boost from fertilizer. If you want to know more about fertilizing hydrangeas, take a look at the information below.
First, we’ve listed our 8 favorite hydrangea fertilizers. Each one has been hand-selected according to its formula, the nutrients it provides, how easy it is to use, and how versatile a product it is.
We’ve also included a handy buyers’ guide that includes everything you need to know about hydrangea fertilizers. We cover all of the important stuff, from the best ingredients in fertilizers to how to best use them. Check it out!
Scotts Company Miracle-Gro Water Soluble Acid-Loving Plant Food
If you’re looking to purchase fertilizer from a tried-and-tested brand with an excellent reputation, give the Miracle-Gro water Soluble Acid-Loving Plant Food a try! This fertilizer will feed your hydrangeas quickly and efficiently.
Specifically, this is a fertilizer that is designed for acid-loving plants, such as azaleas, rhododendrons, and hydrangeas. It features a 30-10-10 N-P-K ratio, meaning that it is high in nitrogen.
This specific combination of active ingredients will help your hydrangeas get off to a robust, sturdy start in the spring. It will also continue to encourage them to vigorously grow throughout the summer.
In fact, this fertilizer feeds both the roots and the leaves through a double feeding action. In turn, this promotes quick and beautiful blooms and strong root development. It also works incredibly quickly, so is a great choice if your hydrangeas are in need of a quick boost.
To use, you need to dilute the fertilizer in water, as recommended by the manufacturer’s instructions. Then, apply the solution to the base of the plant – it’s as easy as that! Repeat this process every 7 to 14 days.
When we tested this fertilizer, we were pleasantly surprised by how easy it was to use. The instructions were very clear, and within a few weeks, our hydrangeas looked amazing! However, if you have quite alkaline soil you might need a few extra applications.
- 30-10-10 N-P-K ratio – high nitrogen formula that is great for strong and sturdy development.
- Double feeding action – promotes quick and large blooms and healthy roots.
- Fast-acting – produces results very quickly.
- Instructions – clear and easy to follow.
- Extra applications needed for alkaline soil – this might be frustrating for some people, depending on how alkaline their soil is.
- Miracle gro water soluble fertilizer miracid acid loving plant food
- Instantly feeds acid loving plants like azaleas, hydrangeas and rhododendrons
- Double feeding action feeds through both the roots and the leaves
- Starts to work instantly
- 3 Pack
Jobe’s Organics Soil Acidifier
Like the fertilizer above, the Jobe’s Organics Soil Acidifier is a boost of nutrition for hydrangeas and other acid-loving plants. This fertilizer is sure to give your hydrangeas what they need to look luscious and healthy.
This fertilizer is an organic granular fertilizer that can be used for decreasing alkalinity in soil. This will help produce the optimum environment for hydrangeas to thrive by providing them with all-natural Sulphur.
Jobe’s Organics Soil Acidifier turns hydrangeas a beautiful blue color, in addition to providing them with the right nutrients to encourage healthy roots. Specifically, the gypsum in this fertilizer helps develop necessary vitamins and enzymes for robust growth.
As a bonus, the fertilizer is made from all-natural ingredients. In turn, this means that this fertilizer is fairly safe to use, even around children and pets. As such, if you have little ones or mischievous pets around, this fertilizer is a good choice.
Before using this fertilizer, the manufacturer recommends doing a soil test. Then, if you’re happy to proceed, simply measure out the amount of fertilizer you need according to the manufacturer’s instructions. Then, mix the fertilizer with the soil, and you’re done!
When testing this fertilizer, we loved how easy it was to use. There was no fuss with trying to dilute it with the right amount of water! Rather, you can mix the fertilizer directly with the soil. Although, the manufacturer’s instructions aren’t the clearest, so we had to check online.
- Organic & natural fertilizer – makes it very safe to use.
- Sulpher – gives plants necessary nutrients.
- Easy to use – application is smooth and simple.
- Instructions – aren’t the clearest.
- Organic granular for decreasing soils alkalinity; provides acid-loving plants with all natural Sulphur
- Omri listed for organic gardening by USDA; certified organic means no synthetic chemicals
- Ideal formula for hydrangeas and blueberries; turns hydrangeas from pink to blue; test soil pH before applying
- Promotes darker green growth; No harmful chemicals that could burn the plant
- Easy pour 6 pound bag; apply at planting, reapply 2-3 times a year to maintain desired soil pH
JR Peter Jacks Classic Blossom Booster Fertilizer
If you’re looking for a fertilizer that is high in phosphorus and potassium, the Jacks Classic Bloom Booster Fertilizer is perfect. It will help your hydrangeas blossom brighter and bigger than you’ve ever seen before!
Specifically, this fertilizer has a 10-30-20 N-P-K makeup. Thanks to the high phosphorus and potassium content, Jacks Classic Blossom Booster Fertilizer increases plants’ bud setting throughout the most crucial point in the growing period.
These active ingredients also work to encourage the plant to produce as many blooms as possible. As such, if you feel as if your hydrangeas have been smaller than they should be, this fertilizer is a really great choice.
Additionally, this blend is designed to also increase the vibrancy of the flower colors. It really is an all-around crowd pleaser! Though, it’s important to keep in mind that this fertilizer should only be used during a bad set.
To use, first measure out the necessary amount of fertilizer according to the manufacturer’s instructions. Then, dissolve in the specified amount of water and pour the solution around the base of the plant, so that it can be quickly absorbed by the roots.
This fertilizer brought life back to our hydrangeas. Honestly, we thought they were beyond help! It made our garden look so much brighter and fuller, and helped maintain the overall health of the plants. Though, the effectiveness may depend on existing soil conditions.
- 10-30-20 N-P-K ratio – high phosphorus and potassium content is great for encouraging health.
- Designed for use on bad sets – means it should bring struggling hydrangeas back to life.
- Increased brightness of blooms – makes plants look great.
- Soil conditions – effectiveness may depend on the preexisting soil conditions.
- Free measuring spoon enclosed for easy and precise application
- Features the highest safety factor to prevent burning when applied as directed
- Blended with an enhanced micronutrient package which provides optimal nutrition for strong roots and green foliage
- Feeds through both roots and leaves
Osmocote Smart-Release Plant Food
If you’re looking for an all-in-one solution for potted plants, look no further than the Osmocote Smart-Release Plant Foor. This fertilizer is also great for busy plant owners, as it is very low maintenance!
Fortified with 11 different nutrients, this fertilizer really gives plants a good boost. Including ingredients such as sulfur, boron, copper, iron, manganese, molybdenum, and zinc, the Osmocote Smart-Release Plant Food really contains everything your hydrangeas need!
This fertilizer is also very versatile. In addition to being capable of bringing a new lease of life to your hydrangeas, it can give a boost to virtually all plant varieties and it can also be used in all growing conditions. As such, this one is perfect if you have a lot of different plants!
However, the best thing about this fertilizer is how easy it is to use. Simply sprinkle one scoopful of food per 2 gallons of water or 4 square feet. Mix this into the top few inches of soil, and water plants regularly.
You only need to reapply this fertilizer once every six months (yes, you read that right!). Thanks to the unique resin that coats each granule, the release of nutrients are slow and controlled, meaning that the plants get what they need when they need it.
As busy people who work full time, this fertilizer was perfect. Not only did it produce excellent results, but we barely even needed to think about applying it! Though, we recommend putting a date in the calendar for reapplication, as it is easy to forget!
- Fortified with 11 different nutrients – gives plants everything they need.
- Appropriate for many different plants and growing conditions – makes for a very versatile product.
- Easy and low maintenance – great for people who are very busy.
- Slow working – not great if you need big, instant results.
- OSMOCOTE QUALITY: Osmocote is the original slow-release plant food. Decades of rigorous field testing confirm product effectiveness with hundreds of plant species in a variety of climate and soil conditions.
- OSMOCOTE’S BEST FORMULA: Each homogeneous granule contains 15-9-12 NPK plus micro and secondary nutrients and feeds up to 6 full months.
- OSMOCOTE’S SECRET: Soil temperature controls how Osmocote releases its nutrients, and more importantly how nutrients are taken up by the plant. Replenishment and feeding are in natural harmony.
- OSMOCOTE’S DIRECTIONS FOR USE: 1 pound of Osmocote covers 37.5 sq. ft. (approx. 6’ x 6’). Works best when mixed into 1 – 3 inches of soil. Package includes applicator. In containers, mix 1 pound with 19 gallons of potting soil.
- OSMOCOTE IS MISTAKE-PROOF: Even if over-applied up to 3x the recommended rate, Osmocote does not ‘burn’ the plant.
BioAdvanced All In 1 Rose and Flower Care
If you’re more comfortable with liquid fertilizers, you can’t beat the BioAdvanced All In 1 Rose and Flower Care. Like the fertilizer above, this one is also really great for busy people who don’t have a huge amount of time to dedicate to their gardens.
With this product, you get three benefits in one. It fertilizes and helps with both insect control and disease control. In particular, it protects your plants and flowers from insects such as Japanese beetles, aphids, and leafminers, and diseases such as black spot and rust.
With a 9-14-9 N-P-K ratio, this fertilizer is high in phosphorus. In turn, this means that it provides all the necessary nutrients to encourage sturdy and healthy growth. It both promotes strong roots and also beautiful, large blooms.
In addition to being appropriate for hydrangeas, this fertilizer can be used on all types of flowers and flowering shrubs. As such, if you are also growing roses, iris, hibiscus, azaleas, camellias, or rhododendrons, this fertilizer will go a long way!
To use, all you need to do is fill a bucket or watering can with the appropriate amount of concentrate and water. Then, pour as close to the base of the plant as possible. Follow by watering the rest of the plant. You only need to repeat this process every six weeks!
We really loved how easy this was to use. Its liquid nature meant that there wasn’t any residue left in the soil. However, be careful to not pour the fertilizer onto the leaves, as this can cause them damage.
- 9-14-9 N-P-K ratio – high phosphorus content means that this formula gives plants the nutrients they need to encourage sturdy and healthy growth.
- Can be used on all types of flowers and flowering shrubs – great for people with different types of flowers that need fertilizing.
- Easy and low maintenance – makes this product great for busy people.
- Insect and disease control – makes for a great all-in-one product.
- Ingredients – some of the ingredients could harm bees.
- PLANT FOOD: Promotes strong roots and beautiful blooms
- INSECT KILLER: Kills Japanese Beetles, Aphids, Leafhoppers, and other listed pests
- DISEASE CONTROL: Fungicide controls Black Spot, Powdery Mildew, Rust, Southern Blight and more
- RAINPROOF PROTECTION: Systemic rainproof protection lasts up to 6 weeks and treats up to 32 roses
- RESTRICTIONS: Restricted in CT, MD, MA, ME, NY, & VT.
Element Nutrients Flower Fuel 1-34-32
If your main goal is to achieve larger, heavier, and denser harvests, Element Nutrients’ Flower Fuel is perfect. It is a super-premium bloom booster that will have your hydrangeas looking incredible in no time!
With over 40 proprietary ingredients, consisting of nutrients, vitamins, hormones, amino acids, essential organic components, and all the micro and trace elements you need, this fertilizer really packs a punch.
This hydroponic-grade bloom booster is designed to be used on top of your favorite base flower nutrient and is formulated from the highest quality ingredients. In turn, this helps produce the largest, most colorful crops possible.
This Flower Fuel encourages plants to absorb and utilize essential nutrients and organic compounds at a very quick rate. As such, you should see results pretty quickly with this product!
To use, simply add ¼ teaspoon per gallon of feed water. There is a ¼ teaspoon and a 2.5 teaspoon measuring scoop included with the product! You can use this product throughout the ensure flower cycle, but remember to use it along with your base nutrient.
When testing this product, we thought it did a very good job with our hydrangeas. It made them look far brighter and denser. We noticed that it also helped to fight off pests and disease, which was a useful bonus!
- Over 40 great ingredients – this fertilizer has everything your plants might need.
- Hydroponic-grade high-quality bloom booster – means this is a safe and effective purchase.
- Measuring scoop included – makes fertilizing much easier.
- Packaging – some reviewers note that the packaging was prone to breaking.
- Flower Fuel is a 100% hydroponic-grade, soluble bloom fertilizer. It works great with any base nutrient (including all popular 2 and 3-part nutrients), and in any soil, coco, hydroponic or aeroponic system.
- Formulated to achieve larger, denser and heavier harvests. That means better looking, more valuable crops for you.
- Over 40 proprietary ingredients go into every jar of Flower Fuel. Among these are powerful nutrients, organic components, and every single trace element you need to grow healthy plants.
- TREATS 200 GALLONS OF WATER! At 10 cents per gallon treated, Flower Fuel is an unbelievable value.
Scotts Super Bloom Water Soluble Plant Food
If your hydrangeas are in desperate need of some phosphorus, you can’t go wrong with Scotts Super Bloom Water Soluble Plant Food. This fertilizer provides hydrangeas with the exact growing conditions they need to thrive!
With an N-P-K ratio of 12-55-6, this fertilizer really packs a phosphorus punch! This is ideal if you’re looking to achieve the perfect blooms. After using this, your hydrangeas should look dense and beautiful in no time!
In particular, Scotts Super Bloom Water Soluble Plant Food transforms the soil pH to make it suitable for acid-loving flowers. As such, it can be used for outdoor flowers, fruiting plants, containers, and bed areas, making it quite versatile!
Using this product is also pretty simple! All you have to do is add two teaspoons of the fertilizer to a gallon of water. It can be handy to use a garden feeder or watering jug. Then, simply apply this solution to the base of the plant. Repeat this process every 1 to 2 weeks.
It’s important to note that the manufacturer’s instructions should be followed precisely and carefully. You should try to completely avoid using any fertilizer solution anywhere other than the base. This is because it could burn the leaves or flowers and thus cause more damage.
When we tried this fertilizer, we could really notice the benefits of the high phosphorus content. Our hydrangeas looked healthier, sturdier, and brighter than ever! Although, we found it a little tricky to avoid pouring the solution on the more delicate parts of the plant.
- 12-55-6 N-P-K ratio – high phosphorus content is great for hydrangeas in need of a boost.
- Can be used with other acid-loving plants – ideal for people who need fertilizer for multiple flowers.
- Clear instructions – means this fertilizer is fairly easy to use.
- Color – may differ with different purchases according to reviewers.
- Contains high phosphorus to help plants bloom
- Feed every 1-2 weeks for best results
- Water-soluble plant food feeds plants instantly
- For outdoor flowers, fruiting plants, containers and bed areas
- Won't burn your plants when used as directed
Jobe’s Organics Garden Lime Soil Amendment
Finally, the last hydrangea fertilizer we would like to recommend is the Jobe’s Organics Garden Lime Soil Amendment. If you want healthier, pink hydrangeas, this product is perfect for you!
Specifically, this fertilizer is ideal if your soil is too acidic. Soil with too low a pH can have poor structure, which can affect the growing process and integrity of the plant. This fertilizer can help by maximizing the alkalinity of the soil to reach the optimal pH of between 6.5 – 6.8.
By altering the pH of the soil Jobe’s Organics Garden Lime Soil Amendment helps to produce wonderfully bright hydrangeas. In particular, this fertilizer aids in the production of the most beautiful pink flowers.
Before using, it is necessary to test the pH of the soil first. If it is appropriate, measure out the necessary amount of fertilizer according to the manufacturer’s instructions. Following, simply mix the fertilizer into the soil.
As a bonus, this product is 100% organic and natural. As such, it is particularly safe. In fact, it’s ideal for people who have small children or pets, as it is not dangerous to either. What more could you want?
We pretty much love anything with the Jobe’s Organics label. Although we have to say, this one really did produce some beautiful plants. The hydrangeas were a bright pink that always caught the eye of any guest we had over.
- Brings down acidity in soil – great for reinforcing the soil structure and thus producing great plants.
- Makes hydrangeas pink – makes for a very pretty and striking outcome.
- 100% organic and natural – safe to use around children and pets.
- Instructions – these are a little unclear, so we had to look online to check the appropriate amounts.
- Organic granular for increasing soils alkalinity, pH; Low pH can cause poor fertilizer response and soil structure
- Most plants grow well in a pH between 6 and 7, with 6.5-6.8 being ideal; below 6.0 Many nutrients cannot be absorbed
- Adding garden lime will increase the pH and make those nutrients available again; test soil pH before applying
- Helps plants like hydrangeas turn pink; creates a healthier, better-producing plant
- Easy pour 6 pound bag; apply at planting, reapply 2-3 times a year to maintain desired soil pH
Before we go onto anything else, it is necessary to get to grips with understanding the N-P-K ratios and what exactly they mean for you.
An N-P-K ratio is a ratio of nitrogen to phosphorus to potassium that makes up a fertilizer. These are the big three primary nutrients within fertilizers. The numbers reflect how much of each nutrient is in the fertilizer. As an example, consider the N-P-K ratio of 10-15-6. In this case, for every 10 parts nitrogen, there are 15 parts phosphorus, and 6 parts potassium.
Now, you might wonder, what do each of these active nutrients do?
Nitrogen is considered the most important nutrient, and plants tend to absorb more nitrogen than any other element. It is mainly responsible for leaf growth and is essential in making sure that plants are healthy as they develop. As such, if your grass or plants are looking more yellow than green and are structurally struggling, they might be lacking in nitrogen.
Generally, phosphorus is considered to be the second most important nutrient and is responsible for root growth and flower development. In particular, phosphorus is linked to a plant’s ability to store energy and photosynthesize. As such, phosphorus is an important nutrient when it comes to hydrangeas.
Potassium tends to help the overall health and function of the plant. Specifically, it helps plants combat and resist disease, and it also plays an important role in ensuring that plants produce a good, large quantity of flowers or crops.
What Hydrangeas Need from a Fertilizer?
Now, it is most important to understand what your hydrangeas need from a fertilizer before you purchase one.
Generally, all hydrangeas enjoy the light and well-drained soil. Ideally, hydrangeas do well with a balanced fertilizer or one that is high in phosphorus. These will have N-P-K values that look something like 12-12-12 or 10-15-5.
You’ll want to avoid high nitrogen fertilizers when it comes to hydrangeas. These fertilizers, especially when they are quickly released, encourage excess foliage growth. With hydrangeas, this comes at the expense of beautiful and dense flowers.
Types of Hydrangea Fertilizer
Fertilizers that are appropriate for hydrangeas come in many different forms. However, they can generally be separated into two distinct categories: chemical fertilizers and organic fertilizers.
These are man-made fertilizers that are manufactured with very specific benefits in mind. Chemical fertilizers are made to have a particular N-P-K value so that they can deliver exactly what a plant needs. They can also be made to be fast-release or slow-release.
This is obviously a huge benefit of chemical fertilizers, as there is likely a chemical fertilizer out there for any potential plant issue. However, they aren’t organic, and this can be an issue for many people.
If you plan to use chemical fertilizer on your hydrangeas, there are a few things to keep in mind. First, make sure to choose a slow-release formula that is fairly balanced. Also, keep in mind that these fertilizers need to be covered with a decent amount of soil to work well.
Organic fertilizers are made from materials such as bone meal, manure, alfalfa meal, worm castings, and guano. Organic fertilizers are preferred by many people as they are generally safer and less harmful to the environment.
However, organic fertilizers come with their downsides too. First, it might smell unpleasant or attract local wildlife (but hey, that’s just nature, right?). Secondly, you won’t get as precise or targeted a formula as you would with chemical fertilizers.
How to Fertilize Hydrangeas
How to fertilize your hydrangeas will depend completely on the form of fertilizer you purchase. Below, we’ve made a list of the most common forms of fertilizer, their benefits, and how to best use them. Take a look!
1. Granular Fertilizers
Granular fertilizers are a very popular form of fertilizer, especially for hydrangeas. They are often slow-release and very easy to use, which means they are ideal for anyone who is busy and doesn’t have a huge amount of time available to dedicate to gardening.
To use granular fertilizers, measure out the necessary amount according to the manufacturer’s guidance. Then, you generally need to sprinkle the granules around the base of the plant and water them regularly. However, if the instructions detail a different method, be sure to follow that process.
2. Liquid Fertilizers
Some liquid fertilizers might need diluting with water, and others may not. Generally, some people prefer liquid fertilizers because of how quickly the nutrients can be absorbed by the plant. As such, the benefits of the fertilizer can be more quickly. To use them, you simply pour the product onto the base of the plant, avoiding the leaves and flowers to prevent burning.
However, this also means that liquid fertilizers can be washed away easily too. Therefore, if you’re experiencing a particularly rainy season, maybe opt for a different fertilizer. This can also happen if you overwater the plants, so make sure to avoid overwatering as much as possible.
3. Spike Fertilizers
Though there aren’t any in the list above, if you come across fertilizer spikes with an appropriate N-P-K ratio for your needs, you should definitely give them a try!
These fertilizers are great, especially if you’re very busy. All you have to do is sprinkle the contents around the base of the plant. It helps if you also rake the soil to ensure good absorption. This type also tends to be very slow-release, meaning you don’t have to reapply the fertilizer very frequently at all (generally once every few months).
Frequently Asked Questions
What type of fertilizer is best for hydrangeas?
Generally, hydrangeas do best with a balanced, or high phosphorus fertilizer. You can use either chemical fertilizer or organic fertilizer.
Unless your hydrangeas are in dire need of a quick boost, we recommend fertilizers with slow-release formulas. These tend to produce the best results in terms of bloom size and color. Keep an eye out for fertilizers that you only have to apply once a year, these are great for hydrangeas and are super low maintenance!
What month do you fertilize hydrangeas?
Generally, it is best to fertilize hydrangeas in spring. This will provide them with an early-season boost.
However, if the manufacturer’s instructions suggest otherwise, you should follow their guidance instead. Some fertilizers have specific requirements, and if they’re not followed, you could cause harm to your hydrangeas.
Are coffee grounds good fertilizer for hydrangeas?
Believe it or not, yes!
Coffee grounds provide the soil with an extra boost of acidity. In fact, hydrangea seedlings thrive off the nutrient content in coffee grounds.
For this method to work best, use coffee grounds in composted form 2 to 3 times a year. If you want to more dramatically change the pH of the soil, you can use them more often. To apply, simply scatter the grounds over the soil base of the hydrangea.
Is Epsom salt a good fertilizer for hydrangeas?
To be brief, yes!
Epson salts contain magnesium sulfate and sulfur. These minerals are also found in regular fertilizers and are generally used to lower the pH. As such, they have a similar effect as coffee grounds, in that they will provide the soil with more acidity.
Is baking soda good for hydrangeas?
Baking soda is actually very good for hydrangeas. In fact, you can even use baking soda to change the color of the blooms.
Your hydrangeas will bloom white or pink if the pH of the soil is higher than 6.5. If the pH is less than 6, your hydrangeas will be blue or lavender in color.
Baking soda is alkaline. So, if you want pink or white hydrangeas but your soil pH is too high, add some baking soda by mixing it into the soil.
There are a number of other benefits of baking soda. It is good for root health as it keeps the system cool, it gives plants a health boost, and it reduces the change of fungal disease taking hold!
Are eggshells good for hydrangeas?
Yes! Eggshells contain calcium and this is important for growth in hydrangeas. Calcium makes the plant stronger and works to improve overall health.
However, if you’re interested in reaping the benefits of eggshells, you will first need to do a little bit of work. Namely, the eggshells must be ground into a fine powder before they’re added to the soil. This ensures that the plant can absorb the nutrients from the eggshell.
Are banana peels good for hydrangeas?
They absolutely are. In fact, banana peels make for a great hydrangea fertilizer. First, you will need two or three banana peels per plant. Then, chop the peels into many challenger pieces, and bury them around the base of every plant. In addition to helping them grow and giving them vital nutrients, banana peels also help hydrangeas repel pests, such as aphids. Who knew?
Will vinegar make hydrangeas blue?
Potentially. Although vinegar is acidic, and acidic products encourage hydrangeas to turn a blue or lavender color, vinegar is likely to wash away quickly with watering and rain.
That being said, it does sometimes work! If you want to give it a try, mix some apple cider vinegar with water and pour it over the soil. Then, simply make sure you don’t overwater the plant, and keep your fingers crossed!
Do you need to fertilize hydrangeas?
Generally, yes. Hydrangeas simply grow best if they are fertilized once or twice throughout the growing season. Saying that, hydrangeas do well with a very relaxed approach to fertilization, so don’t stress about it too much!