Skip to Content

Tips for Fertilizing Hydrangeas to Get Larger and Vibrant Blooms

Sharing is caring!

Hydrangeas, with their lush foliage and large, vibrant blooms, are a centerpiece in many gardens. However, achieving those show-stopping flowers often hinges on a factor that many gardeners overlook: proper fertilization.

Fertilizing hydrangeas effectively is not just about providing them with nutrients; it’s about ensuring these nutrients are delivered in a way that maximizes bloom quality and plant health. This guide offers actionable steps to help you optimize your hydrangea fertilization practices.

Understand Your Soil: Start with a Soil Test

Before you even think about fertilizing your hydrangeas, it’s crucial to understand the type of soil you’re working with.

Soil testing is a fundamental first step as it reveals pH levels and nutrient content, which significantly influence your fertilization strategy. Here’s how to do it:

Collect Soil Samples

Take soil from several locations around your hydrangeas, from about 4-6 inches deep.

Send for Analysis

Many cooperative extension services offer soil testing. These tests will provide detailed information about pH, major nutrients, and trace elements in your soil.

Hydrangeas particularly thrive in soil with a pH that allows them to uptake aluminum, influencing bloom color—especially in varieties that can switch between pink and blue flowers.

Adjusting the soil pH according to your hydrangea type can drastically enhance their color and bloom.

Select the Right Fertilizer: Match Your Soil Needs

Choosing the right fertilizer for your hydrangeas is pivotal and should be guided by the results of your soil test.

Hydrangeas generally require a balanced fertilizer, but the specific formula you choose should complement what your soil inherently lacks.

Organic vs. Chemical Fertilizers

Organic fertilizers, such as compost or bone meal, release nutrients slowly and improve soil structure.

Chemical fertilizers provide immediate nutrient availability but must be applied more carefully to avoid overfeeding and potential root damage.

Fertilizer for Color Enhancement

For blue hydrangeas, look for a fertilizer high in potassium and low in phosphorus to help them absorb aluminum from the soil. Conversely, pink hydrangeas benefit from higher phosphorus content to block aluminum uptake.

Understanding these nuances ensures that your hydrangeas get exactly what they need for optimal growth and bloom development.

Time Your Fertilization: Maximize Absorption and Growth

The timing of fertilizer application can be just as important as the type of fertilizer used. Hydrangeas typically benefit most from being fertilized in spring and early summer, as this coincides with their growth spurts.

Spring Application

Apply a light fertilizer following the last frost. This early boost helps kickstart growth as the plant exits dormancy.

Summer Feeding

A second application in late spring or early summer can support budding and help strengthen the blooms that are forming.

Avoid fertilizing hydrangeas late in the season. Late fertilization can promote new growth that will not have time to harden off before the frost, making the plant vulnerable to winter damage.

Apply Fertilizer Properly: Techniques for Best Results

Applying fertilizer correctly is essential to prevent damage to your hydrangeas and ensure that nutrients are utilized effectively:


Scatter granular fertilizer evenly around the base of the hydrangea, extending out to the drip line (the area directly beneath the outer circumference of the branches). This method helps distribute nutrients broadly as roots tend to spread wide rather than deep.


Apply a band of granular fertilizer around the drip line. This method is more targeted and can be more effective for plants that have established a wide root system.

Foliar Feeding

Use a liquid fertilizer to spray directly onto the leaves. This method is fast-acting and can be useful if your plant shows signs of nutrient deficiency during the growing season.

When applying fertilizer, always ensure that it does not come into direct contact with the stems or leaves, as this can cause burn injuries.

After applying, water your hydrangeas thoroughly to help dissolve the fertilizer and carry the nutrients down to the roots.

Water Wisely: Hydration to Support Fertilization

Watering plays a crucial role in how well your hydrangeas can absorb and utilize the nutrients you provide through fertilization. Hydrangeas are known for their water-loving nature, but there is a fine balance to maintain.

Consistent Moisture

Keep the soil moist but not waterlogged. Hydrangeas thrive with consistent moisture, especially during high heat in summer.

Best Watering Practices

Water at the base of the plant to avoid wetting the foliage, which can lead to fungal diseases. Early morning watering is preferable as it allows the water to soak deeply into the soil and prevents evaporation.

Post-Fertilization Watering

After applying fertilizer, irrigate thoroughly to help dissolve and distribute the nutrients into the soil, reducing the risk of root burn and ensuring the nutrients are accessible to the plant.

Monitor Plant Health: Adjust as Needed

Regular observation of your hydrangeas will help you tailor your fertilization and care practices to best suit their needs. Vigilance is key to responding to potential issues before they become problematic.

Look for Signs of Nutrient Deficiency

Yellowing leaves or lackluster blooms can indicate a deficiency. A nitrogen deficit, for example, typically causes general yellowing, particularly of older leaves.

Watch for Over-Fertilization

Symptoms include burnt leaf edges or unusually rapid growth that makes the plant weak and floppy. If you suspect over-fertilization, flush the soil with water to dilute nutrient concentrations.

Adjust Fertilization Accordingly

If your hydrangeas are not responding well to the current fertilization regimen, consider altering the type, quantity, or frequency of fertilizer applications based on the plant’s health and growth.

Avoid Common Mistakes: Fertilization Pitfalls to Steer Clear Of

Even with the best intentions, certain fertilization errors are common and can adversely affect the health of your hydrangeas. Awareness and proactive management are crucial.


More is not always better. Excessive fertilizer can lead to salt accumulation, which can damage roots and reduce flower production.

Ignoring pH Requirements

Hydrangeas require specific pH levels to absorb nutrients effectively and to showcase vivid bloom colors. Ignoring pH adjustments can result in disappointing bloom colors and poor plant health.

Neglecting to Follow Instructions

Always use fertilizers as directed on the package. Misapplication can lead to nutrient imbalances, poor plant health, and environmental harm.

Fertilizing hydrangeas effectively is about more than just choosing the right product; it involves understanding and responding to the specific needs of your plants throughout their growth cycles.

By starting with a solid foundation of soil testing, choosing the appropriate fertilizer, and applying it at optimal times in the correct manner, you set the stage for vibrant blooms.

Furthermore, consistent monitoring and wise watering practices will ensure that your hydrangeas remain a stunning feature in your garden.

Remember, patience and attention to detail are key in gardening—take the time to understand your plants, and they will reward you with their full beauty.

Sharing is caring!