What is the best fertilizer for hydrangeas?

Hydrangeas are loved for their bright, dramatic flowers that add elegance to any garden. To keep these beautiful plants healthy, they need the right care, including proper fertilization. This guide covers the basics of the best fertilizer for hydrangea, helping you choose the best options and learn how to use them effectively.

 

What is the best fertilizer for hydrangeas?
Image: Blue Hydrangea

A 20-20-20 fertilizer is good for hydrangeas, giving equal amounts of nitrogen, phosphorus, and potassium to support overall plant health. However, using this balanced mix sparingly is important to prevent over-fertilization.

Most hydrangeas are deciduous, meaning they shed their leaves in the fall. However, some types, like Hydrangea, are evergreen and keep their leaves all year. These plants thrive in fertile, well-drained soil with a slightly acidic to neutral pH. They need protection from strong winds and cold weather, so they grow best in spots with morning sun and afternoon shade. While hydrangea blooms are beautiful, they usually don’t have a strong fragrance.

For best growth, hydrangeas need a combination of nutrients, such as potassium for overall plant health, phosphorus for root and flower development, and nitrogen for foliage growth. These plants require well-drained, somewhat acidic soil and regular hydration.

Depending on the kind and growth environment, hydrangeas usually bloom from late spring to early October. An extended flowering time can be achieved with proper care, such as consistent fertilizer and watering.

Furthermore, bigleaf or mountain hydrangea species’ flower colors can be changed by adding soil amendments. Depending on the pH and aluminum content of the growing medium, most of these kinds can produce either pink or blue blooms. In Europe and the United States, hydrangeas are popular garden plants that are produced and sold in large quantities during the springtime holidays.

Know about the need for the best fertilizer for Hydrangea.

As tomato feed is rich in potassium, it can help hydrangeas bloom more profusely. However, to make sure the plant receives all the nutrients it needs, it should be applied sparingly and in addition to a balanced fertilizer. Eggshells are also beneficial to hydrangeas since they enrich the soil with calcium. Eggshells that have been crushed can be put into compost or blended into the soil to help with soil structure and nutrient content.

If the hydrangeas are suffering from low magnesium in the soil, Epsom salt, which contains magnesium sulfate, may be of assistance. It enhances the uptake of nutrients and encourages robust development but applies it sparingly as overuse might damage the plant.

In addition to contributing organic matter to the soil and slightly acidifying it, coffee grounds can be used as a natural fertilizer for hydrangeas. This keeps the soil acidic, which is very beneficial for blue hydrangeas. Planting hydrangeas in well-drained soil, giving them regular watering, and shielding them from inclement weather are all important for their health. Mulching the area surrounding the base can aid in controlling soil temperature and moisture retention.

For color management, aluminum in hydrangea flowers causes blue coloration, but it is only available to the plant if the soil pH is low enough. Adding aluminum sulfate to the soil can turn hydrangea flowers blue, while baking soda can raise soil pH to encourage pink blooms. Vinegar, an acid, can help lower soil pH, promoting blue blooms, but should be used in moderation.

To maintain pink flowers, a balanced fertilizer like 10-10-10 combined with garden lime is recommended. Adjusting soil pH is a gradual process; follow application directions carefully to avoid harming the plant. Regular mulching, proper watering, and nutrient management are key to keeping hydrangeas thriving.

List of Best Fertilizer for Hydrangea

Making your hydrangea fertilizer at home can be cost-effective and efficient. One easy recipe is to mix equal parts of compost, well-rotted manure, and a balanced, all-purpose fertilizer. This combination slowly releases nutrients, promoting healthy growth and vibrant blooms. Here are the best fertilizers for the hydrangea:

Compost

Natural fertilizers for hydrangeas, such as compost, well-rotted manure, and organic mulches, gradually release nutrients and enhance soil health over time. These materials provide a slow release of essential nutrients, ensuring steady growth and vibrant blooms. Additionally, compost helps retain soil moisture and improves drainage, creating an ideal environment for hydrangeas to thrive.

Azotobacter

Biofertilizers were first applied when the buds sprouted from the main stem. Biofertilizers were added one week later using the soil application chemical fertilizers. Azotobacter, at a rate of 2g per plant, was thoroughly mixed with finely sieved soil and incorporated around the root zone of each plant.

Phosphorus Solubilizing bacteria (PSB)

The application of phosphate-solubilizing bacteria (PSB) enhances phosphorus solubility in soil. Apply 2g of PSB per plant, thoroughly mixed with finely sieved soil, and incorporate around the root zone of each plant.

Biofertilizers such as Azotobacter and PSB have demonstrated benefits in nitrogen fixation from the atmosphere and the solubilization of fixed phosphorus in the soil. This effect is attributed to the production of plant growth-promoting substances like auxins, gibberellins, and other organic acids near the roots by these biofertilizers. This stimulation enhances plant metabolic activities and improves photosynthetic efficiency, thereby promoting better growth and development of plants.

Plants treated with a combination of Azotobacter and PSB exhibited the shortest time to flower bud formation, the quickest transition from flower bud formation to the harvesting stage, and the longest flowering duration compared to other treatments.

Nitrogen (N)

To promote healthy leaves and stem growth in hydrangeas, apply a recommended fertilizer dose of 80g of nitrogen per square meter. It’s crucial to avoid fertilizers with high nitrogen levels as they may stimulate excessive leaf growth and longer stems while potentially reducing flower production. Additionally, note that inorganic fertilizers consist of synthetic components.

Phosphorus (P)

Encouraging strong root development and enhancing blooming in blue cultivars of bigleaf and mountain hydrangeas involves fertilizing once in spring with a formulation designed for acid-loving plants. Phosphorus is crucial for fostering larger and more plentiful blooms.

For optimal bloom enhancement, consider using a higher phosphorus fertilizer like a 10-20-10 NPK mix. This nutrient supports robust root development and enhances flower production, resulting in an abundance of vibrant blooms.

Potassium (K)

To enhance the overall health and resilience of hydrangeas, it’s beneficial to ensure they receive micronutrients such as magnesium, iron, and sulfur, commonly present in comprehensive fertilizers. Additionally, apply 50g of potassium per square meter to support their growth and development. These nutrients play essential roles in maintaining robust plant health and fortifying their ability to withstand various environmental stresses.

Types of Hydrangea Fertilizer

Hydrangea fertilizers are available in three main forms: liquid, granular, and compressed spikes. From my experience, all hydrangeas, including native varieties, thrive with proper fertilization. When choosing how to fertilize hydrangeas, you have several options, each with its advantages tailored to various gardening preferences.

Liquid fertilizers provide quick nutrient release, granules offer versatility with both slow and fast-release options, and spikes deliver timed or gradual nutrient release. Each type is effective and offers distinct benefits suited to different gardening situations.

Granular Fertilizers

  • Slow-Release Granules

Slow-release fertilizers provide a consistent nutrient supply over an extended period. For hydrangeas and similar plants, apply them once in spring and again in mid-summer to ensure continuous feeding. When opting for slow-release formulas, typically applied to shrubs and trees, do so once or twice annually and lightly cover with soil to activate.

As the initial blooms begin to fade, reapply the same slow-release bloom-boosting fertilizer used in spring. These fertilizers, coated to prevent rapid nutrient release, are typically inorganic and consist of small granules. Before application, it’s essential to scratch the soil surface to ensure proper soil contact, which facilitates gradual nutrient release.

Alternatively, organic choices like compost, manure, or fish emulsion not only enrich the soil and enhance its structure but also provide essential nutrients. They represent an ideal option for gardeners aiming for natural and sustainable fertilization methods.

  • Quick-Release Granules

Although they require more regular applications, fast-release fertilizers offer an instantaneous boost in nutrients. Granular fertilizers, that dissolve in water and can be poured into the soil or sprinkled around the base of the plant, are among the most often used and readily available varieties.

When dissolved in water, granules can be provided as an instant feed to the plant or as a timed-release agent when applied in solid form. Use a fast-release fertilizer sparingly in March, May, and July for the best results. Apply a small amount of liquid iron twice a year or another fast-acting fertilizer to the leaves if they appear sickly or yellowing. Take immediate action to remedy the problem.

Liquid Fertilizers

Fast-acting fertilizers are quickly absorbed by plant roots, making them ideal for providing hydrangeas with rapid nutrient boosts, especially during active growth periods. Liquid formulations deliver nutrients swiftly to both roots and foliage, available either as concentrated solutions for dilution with water or ready-to-use formulas. Application methods vary, including spraying onto foliage or pouring around the plant base. This ensures rapid delivery of essential nutrients, promoting immediate plant health and growth.

Spikes

Spikes are small, thin fertilizer sticks planted upright in the soil around the plant base. They act as a long-term fertilizer solution, gradually dissolving over two or three months. The drawback with spikes is that they only feed the plant in the exact placement spot, and if placed too close to the base or the roots, where the fertilizer is concentrated, the ingredients can burn the plant.

When and How to Use Best Fertilize for Hydrangeas

Hydrangeas typically derive significant benefits from fertilization twice annually. Begin by applying the first dose in early spring as new growth initiates, ensuring the plants receive essential nutrients for robust development. Follow up with a second application in mid-summer to sustain blooming and overall vitality through the season.

It’s essential to avoid over-fertilization, as excessive nutrients can harm the plant and diminish flower production. Properly applying fertilizer is crucial for maintaining the health and vigor of your hydrangeas. Follow these steps meticulously to achieve optimal results:

Timing

Hydrangeas should be fertilized as soon as new growth appears in the early spring. If necessary, a second application may be submitted in the middle of summer.

Application

  • For granular fertilizers, uniformly distribute the suggested quantity around the plant’s base, taking care to keep the fertilizer away from the stems. Using plenty of water facilitates the fertilizer’s soil penetration.
  • For liquid fertilizers, mix the fertilizer straight into the soil surrounding the plant after diluting it as directed on the package.

Avoid Over-Fertilization

Over-fertilizer can cause hydrangeas to overgrow their leaves at the price of blossoms and possibly even damage their roots. Never deviate from the prescribed dosage.

Tips for Healthy Hydrangeas

Soil Testing

To find any nutritional shortages and check pH levels, start with testing the soil. Based on these findings, modify your fertilization schedule to maintain the best possible health and growth for your plants.

Mulching

Surround the base of hydrangea plants with a layer of mulch after planting. Mulching benefits plants by keeping moisture in the soil, reducing temperature changes, and releasing nutrients gradually as it break down.

Watering

To prevent waterlogging, keep hydrangea soil conditions continuously wet. Make sure to water your plants frequently, especially in the dry seasons, to encourage strong growth and blooming.

FAQs

Q1. Why is my hydrangea wilting?

The following may be the cause of hydrangea wilting:

  • Water stress

Underwatering can cause dehydration and wilted leaves as the plant lacks sufficient moisture to support its structure and functions.

  • Overwatering

Overwatering can lead to root suffocation and root rot, restricting the plant’s ability to take up water effectively, despite appearing wilted.

  • Sun exposure

Direct sunlight can also contribute to wilting, as hydrangeas prefer partial shade and can struggle in excessively hot conditions.

  • Pest and disease

Pests or diseases affecting the roots or vascular system can impair water uptake, resulting in wilted foliage.

Q2. Why isn’t my hydrangea blooming?

The following may be the reasons:

  • Excess nitrogen

Over-fertilization with high-nitrogen fertilizers can stimulate excessive leaf growth at the expense of blooms.

  • Lack of sunlight

Hydrangeas thrive in bright morning light and partial shade during the afternoon. If they receive too much shade, they may produce elongated, floppy stems and fail to bloom properly.

  • Extreme winter

Before flower buds bloom in the spring, they might be damaged by severe winters or late frosts.

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