Hydrangeas are a common sight in many gardens in America. They’re the second-most-common deciduous shrub and are easy to grow aside from their consistent need for water. Also known for the variety of sizes and colors of their flowers, hydrangeas are some of the most beginner-friendly floral options because you can tell with a glance whether they need extra care.
A good way to cut down on this need for maintenance is by adding some fertilizer to the soil. Fertilizing your hydrangeas will keep them fresh and healthy for the entire season, aside from helping them produce vibrant and beautiful blooms; and with so many brands out there, it’s difficult to tell what is the best fertilizer for hydrangeas in your own garden.
In this guide, we’ve compiled the brands that offer the best fertilizer for hydrangeas. We’ll talk about their ingredients, what makes them so effective, and what things you should keep in mind when you’re buying one.
- Top 6 Hydrangea Fertilizers You Should Get For Your Garden
- Miracle-Gro Water Soluble Miracid
- Espoma Organic Holly Tone
- Espoma Organic Soil Acidifier
- Dr. Earth Acid Lovers Organic Fertilizer
- Jobe’s Azalea, Camellia & Rhododendron Fertilizer Spikes
- Jack’s Classic Hydrangea Blue
- How To Choose The Best Fertilizer For Hydrangeas?
- Things To Keep In Mind When Fertilizing Hydrangeas
Top 6 Hydrangea Fertilizers You Should Get For Your Garden
Hydrangeas are resilient with the proper care, but they won’t bloom into picturesque flowers without the right fertilizer. Each of these brands has a different mechanism of action and NPK ratio, which can affect different hydrangea/soil quality overall.
For an all-around solution for kick-starting a hydrangea garden, we recommend Miracle-Gro Water Soluble Miracid. It’s a budget-friendly fertilizer that can cover a wide area and still have all the nutrients that boost your hydrangea’s growth at all stages.
With an NPK count of 30-10-10, it’s front-loaded with all the nitrogen that acid-loving plants like hydrangeas need. It lowers the pH of the soil by a considerable amount which is great if you have alkaline soil that may lock in some essential nutrients needed by your flowers to survive.
Aside from the high nitrogen count, it also comes with a good supply of phosphorus to help your blooms establish a sturdy root system. Hydrangeas will often have very fragile root systems, even if buried underneath 2 to 3 inches of mulch. You need to add phosphorus to make sure they stay upright while getting all the food they need from the soil.
Application is easy: as a water-soluble mix, just follow the instructions on the packet and sprinkle at the base of your hydrangeas. Since it’s a liquid solution, it’ll flow into your plant’s nutrient pathways and provide it with the nutrients it’s missing. Feed every one to two weeks, basing your schedule on whether your hydrangeas respond to it or take some time to perk up again.
What we like about this product is at 4 pounds, it’s one of the more cost-effective solutions to wide areas of hydrangeas. It’s not meant for seedlings that have been planted, but it’ll perform well with adult patches suffering from an iron deficiency or need general fertilizing.
One thing to keep in mind about this product is to avoid application to other surfaces aside from soil. The increased nitrogen/iron ratio in the formula stains on surfaces like concrete, so drip feeding or using a watering can is preferable over spraying. If some product gets on these surfaces, rinse them well with water before it settles into the cracks.
Another thing to note is because it’s a liquid solution, it works on a fast-release mechanism that can be interrupted if you flood your plot with water or if it rains. The best time to apply this brand is on a somewhat sunny day after watering your hydrangeas.
Trusted by professional florists, Espoma’s Organic Holly Tone fertilizer is ideal for hydrangea seedlings and other plants that don’t require a lot of maintenance but still bloom well. It’s one of the stronger formulas on the market and can perk up your plot within weeks with minimal effort.
The NPK ratio of this product is much lower than our first pick at 5-3-3, but this ratio works well for a granulated product that relies on a slow-release mechanism to get the nutrients in the soil. It still has a large concentration of nitrogen so your hydrangeas gain nutrients better, and a good amount of potassium and phosphate to help them grow.
Another ingredient in this fertilizer is Espoma’s proprietary Bio-Tone Beneficial Microbes. These microbes support the bacteria and other microorganisms already in your soil, helping them improve soil quality to be beneficial to acid-loving plants.
To apply, just coat the surface of your soil evenly with the formula and water afterward. You can leave it on the surface and allow it to sink into the soil so it doesn’t overwhelm fresh plants, or you can work it into the first 1-3 inches of topsoil or mulch for mature plantings. It stays on for one month before you need to reapply, so it’s easy to just fertilize and forget about it for a while.
As an organic product, you don’t have to worry about the potential effects of introducing a fertilizer like this on surrounding plants and soil. This is a significant feature to keep in mind if your garden has more than hydrangeas on it, or is surrounded by water/open to wildlife.
What we like about this product is that it’s one of the easiest fertilizers to use for almost any hydrangea. All you need to do is to apply, water, and keep the feeding period consistent throughout the year, and you’ll have strong plants that bloom during the summer while remaining resilient during winter months.
One thing to note: this is not an emergency aid to wilting and/or damaged hydrangea. It works fast because it integrates into your soil well, but it does not affect your plant, even if you apply it on the stem or leaves. Since it’s a slow-release product, you should only apply it to hydrangeas that need a little nourishment to bloom well, or young/transplanted seedlings that need a boost.
Hydrangeas can grow with most varieties of soil, but they thrive in plots that have low pH levels. A product like the Espoma Organic Soil Acidifier can do the trick if you have the plant but not the soil for optimum growth. By lowering the pH of your soil, plants like hydrangeas can gain better access to nutrients, become more resilient against disease, and grow better flowers.
Because it works by affecting the soil and not the plant, this product doesn’t have an NPK ratio like other fertilizers. They make the majority of the ingredients from sulfur (derived from elemental sulfur and gypsum) that works by affecting your soil’s pH levels. It can counteract alkali input from other sources like your water supply and keep your soil suitable for acid-loving plants.
Most soil acidifiers use ammonium sulfate to lower soil pH levels. But this method is destructive since your plants can suffer from sulfide poisoning, choking their nutrient pathways with salt and frying them from the inside. Since the primary derivative of this product is elemental sulfur, it’s an organic way for you to lower your soil’s alkaline level and not kill any hydrangeas you plant on it.
To apply, all you have to do is to apply it with an even coat on your soil. For the best results, you should do this before you plant any hydrangeas on the plot at all, but just spreading them around the base of mature bushes should do just fine. Work it into the top layer of the soil and water after application. Reapply every two months.
A benefit to using this soil acidifier is that it affects the color of the hydrangeas you plant, turning them into a periwinkle blue that’s otherwise difficult to get without dyes or special chemicals. It’s even possible to change your hydrangeas from their original color into blue with regular applications, since the soil pH turns into an environment that can nurture this kind of growth.
One thing to note about this product is while it’s an effective formula, it takes some time before it’s able to lower the soil pH to an acidic level. You should choose a fast-release soil acidifier instead if you’re trying to lower the alkaline levels in your soil quickly. For serious issues, it’s even best that you transplant your hydrangea into fresh soil.
It’s also not a direct fertilizer, so if you want your hydrangea to benefit from additional nutrients, you should look for a proper fertilizer with an NPK ratio.
An excellent acidic plant fertilizer, Dr. Earth Acid Lovers Organic Fertilizer is packed with all the essential nutrients that a plant needs. While it’s not tailored for hydrangeas, it still provides a useful amount of multi-minerals to support its growth.
With an NPK ratio of 4-5-4, it has a higher concentration of phosphorus to help your plants gain nutrients from the soil. Since hydrangeas can sometimes have a weak root system (when transplanted or are still growing) establishing a robust root network can help them survive better even during harsher weather.
This fertilizer also contains eight select strains of mycorrhizal fungi, which form around your plant’s root systems and increase the availability of nutrients in the soil. They also help it become more drought-resistant, which is critical for a plant that needs frequent watering.
Seven champion strains of probiotics ensure that the microbes in your soil perform even better. These microorganisms regulate the flow of nutrients to your hydrangeas so they get everything they need, prop up the nitrogen fixation so they can grow better, and detoxify any pollutants in the soil. The better the microbes are in your soil, the healthier your garden will be.
You can apply this product in a variety of ways: as a dry material, mixed into mulch, or even fertilizer tea. For hydrangeas, we recommend dispersing it across the base near the stems, mixing it with the topsoil, and watering it regularly. Each application can last for up to two months. You can mix liquid applications in a watering can, but it will need weekly doses to take effect.
What we like about this product is that aside from being an all-organic base, it’s safe to use around pets and other animals. A fertilizer being organic isn’t an automatic guarantee that you can use it around pets since some organic ingredients can irritate or harm animals. So if you have a hydrangea garden and a pet that likes to play in it, putting this formula in shouldn’t affect them at all.
One drawback to this product is that it smells like food to animals like squirrels, skunks, and raccoons. You should take steps to make sure that they don’t mess up your mulch and damage your flowers if you know there are some around your hydrangeas. One way is to mix the formula with cayenne pepper when applying, though this solution works much better with dry application.
Jobe’s Azalea, Camellia & Rhododendron Fertilizer Spikes are an easy and effective way to provide your plant with nutrients if you keep your hydrangeas in pots or are dealing with fresh transplants/seedlings. Pre-measured and pre-packaged, it’s the ideal solution for smaller home gardens.
With an NPK count of 9-8-7, it’s one of the most well-balanced fertilizers on the market right now. An even NPK ratio means that each nutrient is in sync so your plant doesn’t get overwhelmed by any excess nutrients it doesn’t need, which is great for beginners that know little about fertilizer.
The ingredients also include sulfur and calcium, two nutrients that help plants become more resistant to pests and disease while developing their nutrient pathways. Your hydrangea will get better access to water, grow better even in substandard conditions, and be able to use the nutrients it gets more efficiently.
Apply by sticking the spikes into the base of your plant near the roots. Reapply after 8 weeks, or when you notice that all of it has absorbed the nutrients into soil. Since they’re pre-measured, you don’t have to worry about the ratio of the fertilizer you use: one spike per plant should be enough.
Convenience is the best part of using this product. For busy plant owners or amateur florists, fertilizer spikes are a low-risk, high-reward feed that can help their plants grow even without their attention. As a slow-release fertilizer, you don’t have to worry about an inconsistent flow of nutrients to your plant. The spikes drill into the ground for a more direct path to your hydrangea’s nutrient pathways, ensuring they can benefit from this product.
If you’re applying this in a garden, the spikes are also resistant to being washed away by the rain or swept away by the wind. Their pre-packaged form makes them more susceptible to being carried away by animals that may mistake it for food, so make sure you have the proper protection in place if your area has a lot of wildlife.
Pre-packaged fertilizer has no runoff, no waste products, and no hazards or smells. However, it can be lacking if you have a larger garden to take care of or have mature hydrangeas that need more nutrients. Since it’s a slow-release product, it also can’t work as fast as liquid formulas to help your plants. You should look for a better option if you feel you need a faster way to improve your hydrangea’s health.
Jack’s Classic Hydrangea Blue is one of the cheapest options you can get for hydrangea fertilizer, and it works well to keep them in good shape. Easy to apply and requires minimal effort, it’s the best budget option for anyone looking for their first fertilizer for acidic plants.
The NPK ratio of this product is at 7-3-3, with a high nitrogen ratio to help young hydrangeas establish good nutrient pathways to make use of the surrounding soil. It’s also great for transplanted seedlings that need a bit of a boost before acclimatizing to their new soil, and mature plants suffering from nitrogen deficiency.
It also contains a bit of sulfur, which helps by lowering the pH of your soil to a level that your hydrangeas can thrive in. While plants don’t need a lot of sulfur to grow, giving them enough of it can stave off common plant diseases and loss of vitality. With regular application, you’ll see your hydrangeas perk up and become more robust during the blooming season.
To apply, spread an even layer of product on the surface of your soil, near the base of your plants. Do not apply directly to foliage, since it can cause them to burn. Follow the instructions on the package and make sure your measurements match up to the surface area recommended with most hydrangeas. Proper measurement is critical, otherwise you can end up hurting your hydrangeas and overloading the soil.
What we like about this product is that it’s easy to find and purchase in bulk, which is great for extensive gardens that have plenty of hydrangeas in them. Because of the high nitrogen ratio, it’s also an excellent way to make them turn blue, though it may need repeat feeding before you get the shade that you want.
However, a common user complaint is that while this formula works well, it’s easy to get wrong if you’re inexperienced with using fertilizers or have no idea of what hydrangeas need. Since it’s derived from ammonium sulfate, it affects the area more if you get the concentration wrong. If you’re unsure about how fertilizer works, you should choose another brand.
One thing to keep in mind is that this product can have a bit of runoff, which can be dangerous if it’s surrounded by water. If your garden is right next to a fish pond or a similar fixture, it’s best to make sure there’s an effective barrier that doesn’t allow any leeching to the surrounding soil.
How To Choose The Best Fertilizer For Hydrangeas?
Now that you have some brands to choose from, what should you keep in mind when choosing a fertilizer? Here are 7 suggestions, straight from florists:
Each fertilizer comes with an NPK (Nitrogen, Phosphorus, and Potassium) ratio, which is essential for ensuring your plants get all the nutrition they need aside from improving the soil. Most experts recommend a balanced ratio for all-purpose fertilizing like 10-10-10. But hydrangeas require more nitrogen than your usual plant because it thrives in acidic soil, so picking a brand that has a higher nitrogen ratio will work best.
Higher levels of phosphorus and potassium aren’t bad either, since they can help hydrangeas establish a root network and make them more resistant to disease. But any fertilizer you pick should always have a high nitrogen count.
Type of Soil
Hydrangeas are acidic plants that thrive in low pH soil. But sometimes, you don’t have access to that kind of soil in your area, which can make growing hydrangeas more challenging. Picking a brand that has a high nitrogen count or acidifies the soil can be a great way to make sure your plants thrive.
If you aren’t sure about the pH of your soil, you can either have it professionally tested or buy a soil tester from your local hardware store. Once you’ve found that out, you can check the ratios best for hydrangeas, which is from 5.5 to 6.5 pH.
Hydrangeas can come in many colors, but two of the most desired ones are pink and blue. One way to get these colors is by injecting the plant with some special chemicals or growing them in dye. But for people that want an organic way of acquiring them, changing your soil’s pH level can do the trick.
For blue hydrangeas: aim for a pH level of 5 or lower
For pink hydrangeas: aim for a pH level of 6.5 or higher
If you find that your hydrangeas are turning purple, that means your soil pH is somewhere in the middle (between 5.5 and 6.5) and you need a fertilizer with a higher or lower nitrogen ratio to compensate.
Synthetic vs Organic
Synthetic fertilizers pack a punch and work efficiently to deliver nutrients to the plant, which can help them recover from a lot of damage or malnutrition. But their drawback is that their synthetic compounds can mess with the area, which can be a huge issue if there are other plants aside from hydrangeas in your plot.
Organic fertilizers are a firm favorite of many florists because they help both hydrangeas and the surrounding soil with no side effects. However, this also means that you have to put in more care since the ingredients work around the plant instead of into it. For gardens in family homes with children or pets, going organic is an excellent choice.
Slow-Release vs Fast Release
The speed at which your hydrangeas get nutrients determines how fast and how well they grow, aside from recovering from the damage. Picking which release mechanism can help your plants better will contribute to their overall health and eventual bloom.
Choose slow-release mechanisms if you don’t want a lot of maintenance, and it suits your soil quality for acidic plants. A fast-release mechanism works better if your hydrangea is suffering from nutrient deficiency and needs plenty of care.
Age Of Your Plants
Young or newly planted hydrangeas will often have trouble getting nutrients from the soil, so you need to pick a fertilizer with a high nitrogen/phosphorus ratio so they can sprout. This can also apply to transplanted hydrangeas that could use a quick boost.
Mature hydrangeas that need help to flower benefit the most from a high potassium count, since it makes them more resilient to disease and pests that they attract. It also helps them produce more vibrant flowers.
Dry vs Wet Formulas
Fertilizers come in two kinds: dry (which are pellets, spikes, or granules,) and wet (either in liquid form or concentrate). Both of which can be ideal to use in different scenarios.
Dry formulas are great for improving soil quality, since they’re consistent with their nutrient application and handle easier than wet products. However, they’re not the fastest fertilizers and young hydrangeas have trouble breaking them down without a root network.
Wet formulas excel at providing nutrients to the plant, and you can water and fertilize them at the same time. But they need a lot of reapplication compared to dry formula, and the rain can wash it away if your area sees a lot of stormy weather.
Keeping these differences in mind is the key to getting the most out of your fertilizer.
Things To Keep In Mind When Fertilizing Hydrangeas
Fertilizing hydrangeas will depend on two things: the age of your plant and the formula you’ve bought. You can find everything else on the packaging, which we encourage you to follow to the letter.
You can apply wet formulas via drip feeding or watering can to young and mature hydrangeas, though they’re much better suited for large patches of land. Unless otherwise stated by the packaging, you can also apply them to the flowers and the leaves themselves for a more direct boost.
Use dry formulas with mature or growing hydrangeas and as prep work for raised beds. Spread them evenly across the soil and water well to make sure that they sink down to the root level. For additional coverage, you can mix them together using a small rake.
The weather is also an important factor in how you fertilize your hydrangeas. If you’re using a wet formula a sunny day is best, so your plants soak up the nutrients fast. You can use dry formulas the same way, but they give better results when used a day before some moderate rain.
When To Fertilize Hydrangeas?
Most of the time, the fertilizer’s packaging will tell you when to apply the product for optimal results. A good rule of thumb to follow is that dry formulas will need less re-application than wet ones.
Two things to keep in mind when fertilizing hydrangeas are their age and health. Young hydrangeas will need frequent fertilization to make sure their root systems develop and help them get enough nutrients from the soil. Mature plants can use more slow-release fertilizers that provide a consistent level of nutrients for better growth.
Picking the best fertilizer for hydrangeas can help you bring out the best in your plants before they bloom. With consistent application and proper care, these resilient plants will be even tougher, bloom better, and grow over larger areas.
If you’re looking for an all-purpose and fast-acting fertilizer, Miracle-Gro Water Soluble Miracid is our top choice. For adding slow-release yet powerful nutrients into the soil, the Espoma Organic Holly Tone is perfect for mature and young hydrangeas alike. And if you want to make sure that the soil pH in your garden is low enough for gorgeous blue blooms, the Espoma Organic Soil Acidifier is your best bet.
Always keep your hydrangeas well-watered and monitor them closely, especially during the hot summers and pre-winter months. If done well, you’ll have a picturesque and thriving garden of flowers that you’ll love to see outside your window.