Hydrangeas are a popular, hardy plant. Their lush green foliage and bright, colorful blooms make hydrangeas a popular addition to any yard or flower garden.
Fertilizing hydrangeas isn’t hard, but they do have special needs you should consider before choosing the right product. If you’re looking for the best fertilizer for hydrangeas, read on to learn more about what they need and some of the best products out there.
Table of Contents
- Facts About Hydrangeas
- Soil pH for Hydrangeas
- What is the Best Fertilizer for Hydrangeas?
- The 6 Best Fertilizers for Hydrangeas
- Best Hydrangea Fertilizer Reviews
- Soil Amendments for HydrangeasAchieve Optimum Growth
- When is the Best Time to Fertilize Hydrangeas?
- How to Fertilize Hydrangeas?
- How Often to Fertilize Hydrangeas?
Facts About Hydrangeas
Here are some interesting things to know about hydrangeas:
- There are more than 70 varieties of hydrangeas and most are native to Asia.
- Hydrangeas are very thirsty flowers and need regular and frequent deep watering.
- The color that hydrangeas bloom depends on the number of aluminum ions in the soil.
- Most hydrangeas bloom from spring until late into the fall.
- The clusters of flowers produced by hydrangeas every year come from shoots that the plant developed the year before.
- You have to prune hydrangeas carefully to avoid missing a growing season.
- White hydrangeas will always be white, but you can manipulate the color of pink and blue hydrangeas with certain soil amendments.
- Hydrangeas prefer a little shade, but they do fine in full sun, as long as they have enough water.
- You can propagate a hydrangea by using a cutting of a non-flowering branch.
Soil pH for Hydrangeas
The soil pH affects the colors of hydrangeas in interesting ways, although the pH itself is not what causes the shift to pink or blue. It’s actually the availability of aluminum in the soil that does it.
When the pH is 6.5 or higher, the aluminum is held in the soil. The flowers cannot absorb it, resulting in a pink flower. But, when the pH is lower than 5.5, the aluminum is easily absorbed, turning the flowers blue.
When the pH is somewhere between 5.5 and 6.5, the blooms are either a mix of pink and blue or purple.
Because of this, you have some control over the color of your hydrangea by changing the pH. Make the changes slowly, though. A drastic change in pH that happens too fast can be too much for your plants to handle.
What is the Best Fertilizer for Hydrangeas?
While the pH and color are something to keep in mind when fertilizing hydrangeas, it’s also important to make sure you’re giving the plant what it needs to thrive regardless of the color of its blooms.
Like most types of fertilizer, hydrangea fertilizer is available in multiple forms. Liquid fertilizers are quickly absorbed and deliver a quick burst of nutrients.
Most granules are designed to be raked into the soil and watered. They break down slowly, nourishing the plant over a longer period.
Spike fertilizers are similar to granules, only they are larger and pushed or hammered into the soil around the roots. These fertilizers usually last for two to three months.
Another thing to consider is organic vs inorganic. Some people swear that organic fertilizers are better while others get great results from products that use chemicals. Despite anecdotal evidence, both types are effective. This choice really boils down to preference.
Finally, you should consider the NPK ratio. This ratio is the balance of nitrogen, phosphorus, and potassium by weight contained in the fertilizer.
Generally, hydrangeas do great with a general fertilizer with an NPK of 10-10-10. That said, for gardeners trying to increase the quality of the bloom or make a change to the soil, different ratios are required. For example, a higher amount of phosphorus can encourage foliage to grow.
The 6 Best Fertilizers for Hydrangeas
Now that you know a little more about hydrangeas and the type of fertilizer they need, let’s take a look at some of the best fertilizers for hydrangeas available today.
|Pictures||Hydrangea Fertilizers||NPK Fertilizer Analysis|
|Scotts Company Miracle-Gro 1750011 Acid-Loving Plant Food||30-10-10|
|Espoma HT18 Holly Tone||4-3-4|
|Dr. Earth 703P Organic Acid Lovers Fertilizer||4-5-4|
|Down to Earth All Natural Acid Mix Fertilizer||4-3-6|
|Jobe's Fertilizer Spikes||9-8-7|
|EZ-gro Liquid Hydrangea Fertilizer||21-7-7|
Best Hydrangea Fertilizer Reviews
1. Scotts Company Miracle-Gro 1750011 Acid-Loving Plant Food
Miracle-Gro is a trusted brand, and its Miracid fertilizer performs just as well as the other products it is known for. Miracid is wonderful for hydrangeas, but you can also use it on all of your other acid-loving plants, like holly, hibiscus, gardenias, and azaleas.
There’s a lot to love about it, but one of the things we like the most is that it works almost instantly. The double-feeding iron-rich formula nourishes both the leaves and the roots, giving you a beautiful plant with healthy leaves and roots.
When using as directed, you don’t have to worry about burning your plants. For best results, use Miracid every seven to 14 days with a Miracle-Gro garden feeder. Spray at the base of the plants to ensure it gets to the roots.
The one-pound box covers about 400 square feet, which is enough for multiple applications on an average-sized flower bed.
2. Espoma HT18 Holly Tone
Another great option for hydrangeas and any other acid-loving plants is Espoma Holly Tone. This formula is used by professional growers and is approved for organic gardening.
Holly Tone also contains Bio-tone. This proprietary formula adds beneficial microbes to the soil, helping your hydrangeas absorb nutrients while also protecting them against diseases.
According to Espoma, you should use this product twice a year. Use the full recommended rate for the spring application to support your plants through the summer growing season, but only half the recommended rate in the fall.
For best results, apply this slow-release fertilizer under mulch. If you cannot easily remove and replace the mulch, you can apply it on top of it, but be sure to double the rate. Sprinkle the granules around the drip line of your hydrangeas and water thoroughly.
3. Dr. Earth 703P Organic Acid Lovers Fertilizer
A great organic option is Dr. Earth fertilizer for acid-loving plants. This formula continuously feeds your hydrangeas for months, helping them produce healthier and more beautiful blooms.
Using multiple probiotics, including strains of seven soil microbes, this product works to improve the soil to support your hydrangeas’ long-term health. It makes nutrients readily available and easier for the roots to uptake and helps plants tolerate drought conditions.
This organic fertilizer is made in the USA and contains no synthetic ingredients or chicken manure. It’s hand-crafted and all of the ingredients are feed-grade. For best results, apply this fertilizer every two months during the growing period according to the package directions.
4. Down to Earth All Natural Acid Mix Fertilizer
For hydrangeas and other plants that prefer soil with low pH, this all-natural fertilizer mix from Down to Earth is a great choice.
According to the brand, you should apply this product in early spring to encourage leaf growth and again when blooms appear to encourage bright colors and healthy flowers. You can also apply again in the fall to help your hydrangeas make it through the cold winter.
This product comes in one and five-pound boxes, so you can order just what you need to get your hydrangeas through the season.
In addition to being good for the health of your plants, Down to Earth products are also good for the planet. The company uses 100 percent recycled cardboard and vegetable-based ink on all of its packaging.
5. Jobe’s Fertilizer Spikes
If you’re looking for an easy and effective way to fertilize your hydrangeas, check out Jobe’s fertilizer spikes.
There aren’t many fertilizers that are this easy to use. All you have to do is insert the spikes into the ground where the roots can easily access it. There’s no run-off, strong odors, or mess to worry about.
For best results, apply in late spring or early summer to support your plants during active growth. Each spike feeds for eight weeks. Follow the instructions on the package, but generally, you need one spike for every foot of diameter of your plant.
One pack contains 10 spikes, and they come in a resealable, waterproof bag so that you can store what you don’t need.
6. EZ-gro Liquid Hydrangea Fertilizer
For those who prefer liquid concentrate and blue hydrangeas, take a look at this EZ-gro concentrated liquid fertilizer. It’s formulated for hydrangeas and all acid-loving plants and is super easy to mix and use.
EZ-gro’s hydrangea mix features a multi-nutrient recipe to deliver the best nutrition to your plants. It uses a unique combination of nutrients and aluminum sulfate, which enhances the blue color you might be looking for in your blooms.
For best results, avoid applying this fertilizer during the heat of the day. Instead, stick to the early morning or afternoon. Apply to the base of the plants, not the leaves, starting with every two weeks for the first month and then cutting back to once a month.
Soil Amendments for HydrangeasAchieve Optimum Growth
1. Jobe’s Organics 9364 Fertilizer
If you need some help making your soil more acidic, try Jobe’s Organics fertilizer. This product is also ideal if you’re looking for a way to turn your hydrangea from pink to blue. Best of all, it doesn’t use any harmful chemicals that can burn your plant.
This fertilizer is USDA approved for organic gardening, so you know it’s full of healthy, beneficial ingredients, like all-natural sulfur. The resealable easy-pour bag makes it easy to apply and store what you don’t use for later.
For best results, check your soil pH before applying. If necessary, you can reapply this product two or three times a year to make sure your soil pH stays where you want it.
2. Espoma GL6 Garden Lime Soil Amendment
If you need to adjust the pH of your soil to help your hydrangeas get the most from the nutrients and you prefer pink blooms, take a look at this garden lime soil amendment from Espoma.
This product uses a super-fine grade of pelletized limestone available. Because the granules are so fine, they are easy to spread, work quickly, and have fewer hazards than other forms of lime.
A 6.75-pound bag covers about 100 square feet. For best results, do a soil test first. Then, follow the instructions on the package. The rate of application depends on the soil’s current pH, so it’s important to know that before you get started.
3. Espoma GSUL6 Soil Acidifier
If you prefer blue blooms and want to lower the pH of your soil, Espoma Soil Acidifier can help you do just that.
The ingredients are derived from gypsum and elemental sulfur, and this product is much safer than aluminum sulfate because there’s no risk of aluminum building up in the soil. Each application is long-lasting and very effective, helping your acid-loving plants grow strong, healthy, and beautiful.
This product comes in a six-pound bag. How much you need to apply depends on how high your pH is and how much you need to lower it. Just make sure you lower the pH gradually. Too much too fast can stress out your plants.
For optimal results, check your soil pH first. Then, apply 12 pounds of Espoma Soil Acidifier over 100 sq ft for every one point of pH reduction you need. Clay soils may need up to 15 pounds.
When is the Best Time to Fertilize Hydrangeas?
When it comes to fertilizing any flower, timing is important. What fertilizer you use is just as important as when you fertilize them. If you do it at the wrong time, you won’t get the results you want. You may even damage the plant.
There isn’t a single answer about when to fertilize hydrangeas. It very much depends on the climate where you live.
In warmer climates where hydrangeas get a little bit longer growing season, you should fertilize twice a year. Do this once in the spring and again in the middle of the summer. If you live in a cooler climate, one application in the late spring or early summer is usually enough.
That said, you should always follow the instructions on the side of the product you choose. Some products have very specific instructions as a result of the ingredients they use.
Generally, it’s not a good idea to fertilize your hydrangeas in the late summer. Too many nutrients at this point in the growing season can stimulate new growth right before the plant is getting ready to go dormant.
New growth in the late summer is unlikely to survive the cooler fall and cold winter. Though, again, this varies depending on the product and the type of hydrangea you have.
That said, it is sometimes a good idea to apply a slow-release fertilizer when the ground is no longer frozen in the late winter or early fall. This way, the soil will be ready to support healthy growth in spring when the plant is coming out of dormancy.
How to Fertilize Hydrangeas?
How you fertilize hydrangeas depends on the type of product you’re using. Again, it’s important to follow the recommendations on the package of the product you’re using because each one is a little different.
Mix concentrated liquids according to the manufacturer’s instructions. Usually, they recommend a steady rate and tell you exactly how much product to add to a certain volume of water.
Most granules are raked into the top few inches of the soil around the plant’s drip line and then watered in thoroughly.
If you’re using spikes, push them into the ground using your hands or a rubber mallet if necessary. Make sure the ground is not too hard and that there aren’t any rocks preventing you from getting them into place. Place them around the drip line.
Note that these general instructions are for how to fertilize established plants. If you’re planting new hydrangeas, the process can be a little different. Again, check the package to be sure you get it right.
How Often to Fertilize Hydrangeas?
Again, this largely depends on the product you’re using. Some are specially formulated to be applied every three months while others instruct you to apply every two or three weeks.
Liquid fertilizers are applied more frequently than granules of spikes because they are not formulated to last for a long period. Granules last weeks and some spikes can last for months while liquid fertilizers are a one-time feeding.
1. What happens if you over-fertilize hydrangeas?
If you follow the directions on the packaging carefully and do a soil test beforehand, you can avoid over-fertilizing your hydrangeas in the first place. But, accidents happen, and over-fertilizing can have disastrous results.
The first thing you can do is remove as much of the fertilizer as possible. If you added too many spikes, this is pretty simple to rectify. Just take one out using garden gloves and dispose of it appropriately.
If you used granules and you can see them in the soil, take out what you can and add fresh soil. Just be very careful not to damage the roots or stress the plant any more than it already is.
Hydrangeas love water. If you used a liquid fertilizer, water heavily to try to dilute as much of the fertilizer as you can. Use a garden hose and flood the roots of the plant for about 30 minutes.
Flooding the roots is essentially the same as a heavy summer downpour, so the plant should be able to handle it easily. The water will carry away excess fertilizer so it is absorbed deeper into the soil, away from the roots, where it cannot harm your plant.
2. What to feed hydrangeas to make them bloom?
The thing to keep in mind about hydrangeas is that there are many reasons why they might not bloom. Pruning is a huge part of getting a hydrangea to bloom. If you prune incorrectly, you can cut off the shoots that the plant needs to bloom the next season.
Generally, though, hydrangeas don’t need any special fertilizer. They like balanced formulas with a 10-10-10 NPK unless there is something in the soil that needs correcting.
The best thing you can do for your hydrangeas (and any other plant) is to test the soil. If something is lacking, add the appropriate amendments.
If you’re talking about making a hydrangea bloom in a different color, that’s a different story. As mentioned, lowering the pH to 5.5 makes the soil more acidic and turns the blooms blue. Raising the pH above 6.5 turns the flowers pink. If you keep it somewhere in the middle, you’ll have purple blooms or a mix of blue and pink.
3. Can you use coffee grounds to fertilize hydrangeas?
You can! Coffee grounds make the soil more acidic, which turns the blooms blue. So, if you’re looking for blue hydrangeas, coffee grounds are a cheap and easy fertilizer option. That said, the effects of coffee grounds on the soil will not last long, so it’s something you’ll have to repeat regularly if you want to maintain long-lasting results.
Coffee grounds are not the best choice if you have a problem with your soil that you’re trying to correct. A soil test can tell you what your soil needs so you can make sure you’re giving it the nutrients it needs to grow strong. Then, add the coffee grounds to get the blue blooms you desire.
As you can see, fertilizing hydrangeas isn’t complicated, but there is a lot to think about.
There are two things to consider when fertilizing your hydrangeas. One is, yes, you can change their color by raising or lowering the pH. But make sure you do this slowly and don’t aim for huge shifts that can stress the plant.
Second, the color of the blooms isn’t going to matter if the plant isn’t able to produce them. To make sure you get the beautiful blooms hydrangeas are known for, make sure the soil provides the nutrients it needs.
It’s also a good idea to read up on how to prune a hydrangea. Some varieties form shoots the year before they flower. If you cut these off, you won’t see any flowers next year. Even if you use the best hydrangea fertilizer out there.