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Fertilizer for Hydrangeas: How and When to Fertilize

Fertilizing your hydrangeas ensures they bloom beautifully and maintain vibrant health. Understanding the right fertilizer for hydrangeas and when and how to apply it can make all the difference between flourishing plants and ones that merely survive.

Providing the right fertilizer to hydrangeas enhances their growth and flowering potential. Therefore, knowing the optimal timing and method for fertilizing hydrangeas is essential for achieving the best results. Hydrangeas are plants that require a variety of nutrients to thrive and develop properly. This article will guide you through everything you need to know about fertilizing hydrangeas.

What Kind of Fertilizer for Hydrangeas

what kind of fertilizer for hydrangeas

Selecting the right fertilizer for hydrangeas is key to ensuring they grow healthy and produce stunning blooms. Hydrangeas benefit from fertilizers that provide a balanced mix of essential nutrients. Here’s a detailed guide on the types of fertilizers best suited for hydrangeas:

Slow-Release Fertilizers

Slow-release fertilizers are an excellent choice for hydrangeas because they provide a steady supply of nutrients over time. These fertilizers gradually release nutrients into the soil, reducing the risk of over-fertilization and ensuring that your hydrangeas receive consistent nourishment.

Organic Fertilizers

Organic fertilizers, such as compost, manure, or bone meal, are also beneficial for hydrangeas. These natural fertilizers improve soil structure and fertility, enhancing the soil’s ability to retain moisture and nutrients. Organic options are especially good for gardeners looking to maintain an eco-friendly garden. Explore an eco-friendly solution for kitchen waste! Learn how to make a worm composting bin effortlessly, turning scraps into nutrient-rich soil.

Specialized Hydrangea Fertilizers

There are fertilizers specifically formulated for hydrangeas, often containing additional nutrients that support vibrant blooms and healthy foliage. These specialized products can also include soil conditioners that help maintain the appropriate pH level, which is crucial for hydrangea color.

Soil pH and Hydrangea Color

The pH level of the soil can influence the color of hydrangea blooms. Acidic soils (pH below 6) typically produce blue flowers, while alkaline soils (pH above 7) produce pink flowers. Some hydrangea fertilizers contain ingredients to adjust the soil pH, allowing you to achieve your desired flower color. For blue blooms, use a fertilizer that contains sulfur or aluminum sulfate. For pink blooms, a lime-based fertilizer can help raise the soil pH. Learn more about how to measure soil pH.

Recommended reading: What to Plant with Hydrangeas: Best Companion Plants Guide

Best Fertilizer for Hydrangeas

best fertilizer for hydrangeas

Choosing the best fertilizer for your hydrangeas is essential for promoting healthy growth and stunning blooms. Two excellent options are fertilizers with NPK ratios of 7-3-3 and 8-4-8. Here’s a closer look at how these fertilizers can benefit your hydrangeas:

7-3-3 NPK Fertilizer

A 7-3-3 NPK fertilizer is an excellent choice for hydrangeas due to its balanced composition that supports various aspects of plant health:

  • Nitrogen (N): The 7% nitrogen content helps stimulate lush, green foliage. Nitrogen is crucial for overall plant vitality, aiding in the production of chlorophyll and promoting vigorous growth.
  • Phosphorus (P): With 3% phosphorus, this fertilizer supports strong root development and enhances the hydrangea’s ability to produce vibrant blooms. Phosphorus is essential for energy transfer and flowering processes.
  • Potassium (K): The 3% potassium content aids in overall plant health, improving disease resistance and stress tolerance. Potassium also helps regulate water uptake and enzyme activation.

This balanced mix is particularly useful for maintaining healthy plants and encouraging a steady growth rate, making it ideal for hydrangeas that need a gentle, consistent supply of nutrients.

Jack’s Classic 7-3-3 Hydrangea Blue Water-Soluble Fertilizer with Micronutrients to Enhance Blue Flowers, 1.5lbs
  • 7-3-3 Analysis – Great for promoting lush leaves and enhance and maintain blue color in many pink and blue varieties of hydrangeas.

8-4-8 NPK Fertilizer

An 8-4-8 NPK fertilizer provides a slightly higher nutrient concentration, which can be beneficial for hydrangeas during their active growing season:

  • Nitrogen (N): The 8% nitrogen content supports robust leaf and stem growth. This higher nitrogen level can be particularly beneficial in the early stages of the growing season when hydrangeas are developing their foliage.
  • Phosphorus (P): With 4% phosphorus, this fertilizer promotes strong root systems and enhances flower development. Adequate phosphorus is vital for hydrangeas to produce abundant and colorful blooms.
  • Potassium (K): The 8% potassium content ensures that the plants are well-equipped to handle stress and resist diseases. Potassium also plays a role in water regulation and overall plant vigor.

The 8-4-8 formula is ideal for providing a nutrient boost during peak growing periods, helping hydrangeas achieve their full blooming potential and maintaining their health throughout the season.

Recommended reading: Common Hydrangea Problems

GARDENWISE 8-4-8 Acidic Fertilizer for Azaleas, Camellias (Camelia), Hydrangeas, Blueberries, Gardenias, Magnolia Trees, Evergreens, and Rhododendrons – Ideal Iron-Rich Plant Food (1/2 Quart)
  • 🌺 VIBRANT BLOOMS & ROBUST GROWTH: Enriched with essential nutrients like magnesium, iron, and manganese, GARDENWISE 8-4-8 is ideal for preventing chlorosis in acid-loving plants. It’s perfect for azaleas, camellias (camelia), rhododendrons, hydrangeas, and all acid-loving plants including magnolia trees, evergreens, and blueberries.

How to Make a Natural Fertilizer for Hydrangeas

how to make a natural fertilizer for hydrangeas

Creating a natural fertilizer for hydrangeas is an eco-friendly and cost-effective way to nourish your plants. Here’s a simple recipe to make your own natural fertilizer:


  • Banana Peels: Rich in potassium, which promotes vibrant blooms.
  • Eggshells: Provide calcium for strong stems and healthy roots.
  • Coffee Grounds: Add nitrogen for lush foliage and overall plant health.
  • Epsom Salt: Contains magnesium sulfate, which enhances flower color and vigor.
  • Water


  1. Collect Ingredients: Save banana peels, eggshells, and coffee grounds from your kitchen.
  2. Prepare Eggshells: Rinse eggshells thoroughly and allow them to air dry. Once dry, crush them into small pieces.
  3. Blend Ingredients: Combine banana peels, crushed eggshells, and coffee grounds in a blender or food processor. Blend until you achieve a fine, uniform texture.
  4. Mix Epsom Salt: Add a tablespoon of Epsom salt to the mixture and blend again to incorporate.
  5. Store or Use Immediately: Transfer the natural fertilizer to an airtight container for future use, or use it immediately to feed your hydrangeas.
  6. Application: Sprinkle a small amount of the natural fertilizer around the base of each hydrangea plant, avoiding direct contact with the stems. Water the plants thoroughly after application to help the nutrients penetrate the soil.


  • Apply the natural fertilizer in early spring and again in early summer for best results.
  • Adjust the quantities of ingredients based on the size and number of hydrangea plants in your garden.
  • Monitor your plants’ response to the natural fertilizer and adjust your feeding regimen accordingly.

By making your own natural fertilizer for hydrangeas, you can promote healthy growth and vibrant blooms while reducing your environmental footprint. Enjoy the beauty of your lush, thriving hydrangeas!

When to Fertilize Hydrangeas

when to fertilize hydrangeas

Knowing the optimal time to fertilize your hydrangeas is crucial for ensuring they receive the nutrients they need for robust growth and beautiful blooms. Here’s a detailed guide on when to fertilize your hydrangeas for the best results:

Early Spring

The first application of fertilizer should occur in early spring, just as new growth begins to emerge. This timing is critical because it provides the plants with the nutrients they need to support the development of new leaves and stems. Fertilizing in early spring ensures that the hydrangeas have a strong start to the growing season.

  • Timing: As soon as you see new buds forming on the stems.
  • Type: Use a balanced fertilizer, such as a 7-3-3 or 10-10-10 NPK formula, to promote overall plant health.

Early Summer

A second application should be made in early summer, around June or July. This mid-season feeding supports the ongoing growth and prepares the plants for blooming. By this time, the initial nutrients from the spring application may be depleted, so a fresh dose helps sustain the plants through their flowering period.

  • Timing: Once the first flush of blooms begins to fade.
  • Type: Use a balanced or slightly higher phosphorus fertilizer, such as an 8-4-8 NPK formula, to encourage bloom development.

Late Summer (Optional)

Depending on the health and vigor of your hydrangeas, you may choose to apply a third, lighter dose of fertilizer in late summer. This is optional and should be done cautiously to avoid stimulating new growth that could be damaged by early fall frosts.

  • Timing: Late August or early September, if necessary.
  • Type: Use a balanced, slow-release fertilizer to avoid overfeeding and to provide gentle, sustained nutrition.

Important Considerations

Avoid Late Fertilization: Do not fertilize hydrangeas after late August. Late fertilization can encourage new growth that won’t have time to harden off before the first frost, potentially leading to damage.

Monitor Plant Health: Always observe your hydrangeas’ health and growth patterns. If your plants appear lush and are blooming well, additional fertilization might not be necessary.

Soil Testing: Conduct a soil test to determine the nutrient levels and pH of your soil. This can help you tailor your fertilization schedule and choose the right type of fertilizer for your hydrangeas’ specific needs.

Recommended reading: Hydrangea Yellow Leaves – How to Fix Yellow Hydrangea Leaves

How to Fertilize Hydrangeas

how to fertilize hydrangeas

Granular fertilizers are a convenient and effective way to provide essential nutrients to your hydrangeas.

Refer to the fertilizer’s packaging for dosage instructions based on the size and age of your hydrangea plants. Use a measuring cup or scoop to ensure accurate application. It’s essential not to over-fertilize, as this can harm your hydrangeas.

Spread the granular fertilizer evenly around the base of your hydrangea plants, starting a few inches away from the main stem and extending outwards to the drip line. Avoid direct contact with the stems and foliage to prevent burning.

Using a hand rake or gardening fork, lightly scratch the granular fertilizer into the soil surface. This helps incorporate the fertilizer into the top layer of soil where the plant’s roots can easily access the nutrients. Be gentle to avoid damaging the roots.

After applying the fertilizer, water the soil thoroughly to activate the granules and promote nutrient uptake by the roots. Watering also helps prevent the fertilizer from being washed away by rain or irrigation. Ensure the soil is evenly moist but not waterlogged.

Follow the recommended fertilization schedule, typically applying granular fertilizer to hydrangeas in early spring and again in early summer. Monitor your plants’ growth and adjust the frequency or amount of fertilizer as needed based on their response.

Properly seal and store any unused granular fertilizer in its original packaging in a cool, dry place. Store away from children and pets, and avoid exposure to moisture to prevent clumping or degradation of the fertilizer.

Regularly monitor your hydrangeas for signs of healthy growth, including lush foliage and abundant blooms. Adjust your fertilization regimen as needed based on your observations and the specific needs of your plants.

Final Conclusions

In conclusion, fertilizing hydrangeas is essential for promoting robust growth, vibrant foliage, and abundant blooms. Choosing the right fertilizer with the appropriate nutrient balance, such as a balanced NPK formula or specialized hydrangea fertilizer, is crucial for supporting the specific needs of these beautiful flowering shrubs. By applying fertilizer at the correct times, evenly distributing it around the base of the plants, and providing adequate moisture, gardeners can ensure their hydrangeas thrive season after season. Whether using granular, liquid, or organic fertilizers, consistent and mindful application will lead to healthier, more vibrant hydrangeas that enhance any garden landscape.

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the best fertilizer for hydrangeas

About Henry Morgan

Henry Morgan is an agronomist horticulture founder of The Garden Style Company and The Garden Style Website. He previously worked for Mondelēz International as an Agronomist Engineer specializing in agricultural products management in highly populated areas. In 2000, Henry started working with farmer-producers in agricultural businesses selling wholesale fresh produce and retail plants in Van Buren, Arkansas. Nowadays, Henry lives in California, where he offers expert consulting services for organic vegetable gardening. As a science writer working with his wife, Julia, Henry shares his passion for gardening and farming, trying to reach and teach as many folks as possible.

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