Boost Hydrangea blooms with the best fertilizers: A comprehensive guide
Hydrangeas, also known as Hortensia (France and Germany), Ajisai (アジサイ) (Japan), and Bigleaf Hydrangea (United States), are scientifically classified into the family Hydrangeaceae and the genus Hydrangea. This genus consists of over 70 types of flowering plants, usually large clusters of showy flowers, which may be panicles or corymbs.
Hydrangeas were first cultivated in Japan and China because these regions were the first admirers of their ornamental beauty. They featured these plants in scholarly works and decorated their gardens with them.
The primary origin of this plant is Asia, but in the 18th and 19th centuries, the flowers were introduced in Europe, especially by a French botanist named Philibert, who named it "Hydrangea." They cultivated this plant and prepared multiple hybrid breedings, varying in color, size, shape, fragrance, and overall beauty. Hydrangeas are a beloved and luxurious plant grown worldwide in homes and public gardens because of their beautiful blooms and diverse varieties.
Hydrangeas change color depending on the soil PH, mesmerizing and encouraging the gardeners, leading to extensive cultivation. Along with ornamental beauty, their roots are still used to treat urinary tract infections. They also boost soil health, periodically providing organic matter through their fallen flowers and leaves. However, to serve the hydrangeas with the required nutrients for their balanced and healthy growth, it is crucial to fertilize them frequently. Fertilizers can increase the number and size of the hydrangea blooms, and different ingredients prompt different flower colors, like aluminum sulfate, to blue hues. At the same time, garden lime leads to pink tones.
Growcycle helps hydrangea growers by providing them with balanced nutrients, soil PH adjusters, and high-quality tools like pruning, allowing the gardeners to maintain the flower bloom shape. Similarly, they provide modern watering systems to sprinkle an even consistency of water to avoid root rot or advanced drip irrigation systems that use less water but keep the plant moisture longer. They help the growers with different soil amendments, including peat moss and composts, to fulfill the plant growth needs.
Hydrangea Varieties
Each hydrangea variety may vary based on its flower color, size, shape, and fragrance, and that's why they also vary in nutritional requirements. Some of the top varieties, along with their nutritional needs, are the following:
1. Bigleaf Hydrangea
It is the most cultivated hydrangeas variety worldwide, with showy flower blooms that change their colors according to the soil PH levels. This plant usually prefers a bit acidic soil, but it depends on the grower's choice. If he likes blue flowers, it is necessary to provide an acidic environment to the plant, but the soil should be a bit alkaline for the cute pink color. Similarly, this variety flourishes well on slow-release fertilizers, which ensure a steady and controlled supply of nutrients for a longer duration to the plant.
2. Panicle Hydrangea
This variety consists of conical flowers. Initially, they grow green, but later, they turn to beautiful pink flowers over time. Soil pH is not a concern for this variety, and they also do not change color according to the soil pH. However, an ideal range for fast and reliable growth is 5.5 PH to 7.0 PH. Like Bigleaf Hydrangeas, this variety also prefers slow-release fertilizers for optimal growth.
3. Smooth Hydrangea
The flowers of smooth Hydrangeas range from white to pink. The most suitable soil pH is around 6 to 7, so it grows well in slightly acidic to neutral soil. This variety prefers balanced fertilizers to gain a quick but balanced nutrient proportion. It is adaptable and can be cultivated in various climate conditions, even in a fully sunny environment with consistent watering.
4. Oakleaf Hydrangea
Oakleaf Hydrangea gained its name from its oak-shaped leaves. The flowers grow in large clusters with vibrant colors. Again, like smooth Hydrangea, it prefers a slightly acidic to neutral soil and both slow-released and balanced fertilizers depending upon the season and growth stage. A well-drained, partially shady soil is the best choice to grow this variety for optimal results.
5. Climbing Hydrangea
Like other climbing flower plants, climbing Hydrangea can boost the beauty of gardens, offices, and public places. It creates a beautiful view with green leaves and integrated lace cap flowers scrolling on the walls and fences. A balanced fertilizer and acidic to neutral soil are the best choices for this variety to grow fast and healthily. Similarly, well-drained and organic matter-rich soil brings the flowering stage fast.
Top 5 Fertilizers to Boost Hydrangea Blooms
Hydrangeas require fertilization, especially during the growing season, to boost their growth and flowering. Balanced fertilizers help strengthen flower formation and promote healthy blooms. With so many fertilizers available, selecting the right one can be challenging. To make it easier, here is a list of top-quality fertilizers specifically formulated for hydrangea growth:
1. Back To Earth 5# Rock Phosphate
Back To Earth 5# Rock Phosphate is rich in phosphorus content and promotes healthy flowers in hydrangeas. This fertilizer enhances root development and helps the shallow roots of hydrangeas develop their network in the soil and absorb nutrients for robust growth. The plant is famous for its vibrant blooming, and phosphorus makes these blooms long-lasting and attractive.
2. HiYield 12# Aluminum Sulfate
Aluminum Sulfate is a soil amendment that adjusts the soil pH from alkaline to acidic, in which common hydrangea thrives best. HiYield 12# Aluminum Sulfate fertilizer is well-suited for blue hydrangea because the rich availability of aluminum boosts the blue hue in flowers. It stimulates overall plant growth by providing specific nutrients from acidic soil and creating an optimal environment for root development.
3. True Organic 6# Garden Lime pH Up
True Organic 6# Garden Lime pH Up fertilizer is recommended for those who want to transition the soil from more acidic to less acidic, which grows pink hydrangea varieties. It increases the soil pH, nutrient availability, and calcium and magnesium ratios, allowing plants to grow optimally. Making soil neutral to slightly alkaline, the lime promotes vibrant flowering and robust growth in hydrangea.
4. Master Nursery 20# Formula 49
Master Nursery 20# Formula 49 All Purpose Fertilizer Organic Granules contribute to root development and flowering. Using this fertilizer according to the mentioned ratio and procedure provides a balanced nutrient profile for the hydrangea to thrive. The organic nature of this fertilizer improves soil structure and moisture levels and improves microbial activity to activate the beneficial enzymes for growth. Its slow-release nature prevents over fertilization and ensures a continuous nutrient supply for continuous health.
5. Dr Earth 4# Organic Bud Bloom
Dr Earth 4# Organic Bud Bloom Fertilizer ensures a suitable nutrient supply for optimal flower blooming and overall health improvement. The main focus of this fertilizer is to boost bud and bloom development, which contributes to enriching flowering. A balanced nutrient supply improves soil structure by improving microbial activity; use increases soil fertility over time. The organic nature of this product saves the chemical risks of synthetic fertilizers and is sustainable for the environment.
How To Fertilize Hydrangeas?
To avoid commonly occurring fertilizing issues, it is recommended to strategically follow the step-by-step fertilization application plan along with important precautions. This will ensure the plant's fast growth and prevent burns caused by excessive fertilization.
Step 1: Test the Soil
Understanding the soil PH and nutrient levels is crucial before choosing and applying fertilizers. Guessing the soil's needs without proper testing should be avoided because incorrect PH or nutrient levels can cause significant harm to the plant.
Step 2: Choose the Right Fertilizer
The second step is to choose the right fertilizer based on the test results and hydrangea type. A balanced fertilizer with an NPK ratio of 10-10-10 is the most suitable starter fertilizer for all hydrangea varieties. Still, fertilizers with high phosphorus content, e.g., 10-20-10, are the perfect option for plants at the blooming stage.
Step 3: Determine the Timing
Time determination is crucial, especially for plants that go into dormancy in winter. Hydrangea needs fertilizers in the early summer as a new plant, while it needs fertilizers in mid-summer to rebloom. However, applying the fertilizers in late July or August will lead to new growth, which will be damaged by the upcoming winter.
Step 4: Prepare the Soil
Before applying fertilizer, it is important to prepare the soil for equal distribution of nutrients, especially around the plant up to 3 inches wide and deep. This will ensure a fast penetration of the nutrients to the roots, but the process should be gentle to avoid root damage.
Step 5: Apply the Fertilizer
The key to a successful fertilizing process is measuring the right amount of fertilizer based on the hydrangea variety, soil condition, and product description and distributing it equally around the plant base. This ensures that the plant has received the right nutrients in the right amount.
Step 6: Water Thoroughly
The thorough watering of the plant after fertilization guarantees the appropriate dissolution of nutrients in the root zone of the plant. At the same time, avoiding overwatering is crucial to maintaining root health and preventing root rot.
Step 7: Mulch the Base
Mulching means applying a maximum of three inches of organic mulch, which can be purchased from any botanical store around the base of the plant. It prevents root dryness and nutrient leaching, retaining moisture and slowing the nutrient release. However, the mulch should be a bit away from the stem; otherwise, it will cause rot or other pest issues, leading to the degradation of the plant.
Fertilizing Hydrangeas in Containers
To fertilize hydrangeas in containers, it is crucial to first understand the potted plant requirements. The container should be 18 to 24 inches wide and quite deep so that the roots can penetrate deeper to firmly anchor the plant and absorb more nutrients from the soil. The container should also have proper drainage holes to avoid root rot caused by excessive water accumulation.
The container material is also recommended to be weatherproof and easily able to bear extreme and freezing temperatures. High-quality potting soil, regular watering, and dotted shade are crucial for container growth.
Considering all these factors, it is obvious that a container plant requires fertilizers more often than garden plants due to the potential for a consistent nutrient supply from organic soil, which is not available to container plants.
To achieve a balanced feeding strategy for container plants, it is recommended to apply slow-release fertilizer every 4 to 5 weeks during the growing season. Additionally, high potassium fertilizers should be provided from early June to the end of flowering to break the dormancy phase.
Common Hydrangea Fertilizer Issues
Multiple fertilization issues exist for hydrangea, including over or under fertilization, incorrect timing, wrong fertilizer type, and incompatible pH levels. The following is a step-by-step analysis of each fertilization issue and its practical solutions.
Over Fertilization
Over fertilization results in lush green foliage because a high amount of nitrogen can significantly boost the green color and photosynthesis, but it also leads to fewer flower blooms. Using balanced fertilizers that contain all the primary and essential nutrients is crucial. It will reduce the growing cost and get a healthy plant with an extensive range of blooms.
Under Fertilization
Under fertilization results in poor, stunted growth or sometimes complete death. It also increases the risk of diseases and pest attacks on the plant, along with yellowing leaves and weak stems, which makes the plant less resilient to different environmental conditions.
So soil fertility, pH levels, and a balanced nutrient supply using balanced fertilizers are crucial for healthy plant growth and beautiful flower colors.
Incorrect Timing
The wrong timing for fertilization is usually when a plant is in its dormancy period, usually in winter peak. Applying fertilizers at this time can burn the plant because the plant is not using that fertilizer for its growth purposes, so either it will accumulate in the soil and destroy the roots, or if the plant uptakes it from the soil, it will destroy the leaves, stems, and flower blooms creating discoloration and burns. It is crucial to apply fertilizers, especially in summer or spring, which are the active growing seasons of the plant.
Wrong Type of Fertilizer
Wrong types of fertilizer disturb the plant growth and lead to excessive leaf growth while suppressing the flower's development, which is the basic reason for hydrangea growth. As the plant does not need these nutrients for its growth, it results in a micronutrient lock and salt accumulation, which ultimately disturb the water uptake and cause nutrient deficiency against certain nutrients for the plant.
Along with plant root rot, the flower's life span becomes shorter, and the plant produces fewer vibrant and charming blooms. So, it is crucial to choose only fertilizers formulated with hydrangea-specific requirements or those designed especially for flowering plants.
Soil pH Imbalance
Most importantly, soil pH decides the color of some hydrangea flower types. Acidic PH means blue flowers, while alkaline PH means pink flowers. If the soil is too acidic, it will absorb aluminum too quickly and in higher amounts, leading to aluminum toxicity and poor plant health.
It also leads to chlorosis, creating iron deficiency, which leads to yellow leaves and phosphorus lockout, which limits the phosphorus supply to the plant. This results in a few blooms or a complete bloom blackout, along with weak roots. So, choosing fertilizers after testing the soil's pH is crucial.
Hydrangea Fertilizing Myths, Their Realities, And Expert Tips
Multiple myths are associated with hydrangea fertilization; some are partially true, while others are entirely wrong. Here is a complete dissection of these myths, their realities, and expert tips.
1. More Fertilizer Equals Bigger Blooms
Some people believe that more fertilizer results in more flowers, while others believe that it results in bigger blooms, but both are wrong. Like other plants, hydrangeas need a balanced fertilizer for overall plant health and growth, which doesn’t result in bigger blooms.
Fertilizers with high nitrogen quantities suppress flower production rather than creating bigger blooms, so it is advised to avoid using DAP fertilizers that contain extensive amounts of nitrogen and choose fertilizers with a balanced ratio of multiple nutrients.
2. Changing Soil pH Can Alter Hydrangea Colors
This is partially true because certain hydrangea species do not change their colors according to soil pH. One of the top species that hasn’t been affected by soil pH is white hydrangea, which remains only white in every pH type.
So, choosing the hydrangea species wisely is advised, considering all these facts regarding their colors. If the grower wants a vibrant flower rather than pure white, he should use customized fertilizers for specific acidic or alkaline pHs.
3. Hydrangeas Need Full Sun
Some hydrangea varieties need the full sun as they can bear direct sunlight for a longer duration, but this is not specific to all types. In multiple hydrangea varieties, direct sunlight causes leaf scorch and reduces bloom number and quality, leading to light color and unhealthy blooms.
So, it is advised to choose the hydrangea variety according to the respective climate conditions. If a grower chooses a slightly fragile variety, it should be planted in shady areas. At the same time, a variety that needs direct sunlight for more extended hours can also be planted under artificial grow lights if direct sunlight is not possible.
FAQs
How does hydrangea age affect fertilizer needs?
The fertilizing needs of hydrangea can vary according to the plant's growth stages and age. A young plant may need frequent feeding, watering, and fertilization to develop its roots. In adult plants, fertilizer needs are reduced because the well-developed roots can absorb rich nutrients from the soil.
Does winter protection impact next year's nutrient needs?
Winter protection in hydrangeas protects the roots from damage and helps maximize nutrient uptake during growing days. Inadequate winter care leads to weak and developing roots that face stress and struggle to absorb soil nutrients.
When is the best time to plant hydrangeas?
The best time to plant hydrangeas is in the spring or fall when the weather is cooler. This helps the plants establish roots before extreme heat or cold.
The Bottom Line
The natural and durable nature of hydrangea makes it the optimal selection for lawn decoration. Still, for healthy plants with extensive flowers, choosing a fertilizer with high phosphorus content is crucial rather than relying on high nitrogen fertilizers, which lead to a high volume of lush green foliage that suppresses the flower formation. Timing, soil PH, fertilizer type, and hydrangea types all should be considered before choosing the fertilizer for hydrangea to get the desired results.
Consult Growcycle to select the right type of hydrangea according to the respective soil PH, water, and weather conditions. It guides the growers and assists with the right tools, fertilizers, and seeds.
With the right strategy, the lawn will be filled with massive, beautiful blooms that improve the lawn's value and charm and impact human mental health.
Disclaimer: This material is for informational purposes only and should not be relied on for legal, medical, financial, or other professional advice.
About the Author
Victor Miller 
Environmental Journalist Focused on Sustainable Agriculture
Victor Miller is an environmental journalist at Growcycle, where he covers the latest news, trends, and innovations in sustainable agriculture. He has a deep passion for storytelling that emphasizes ecological balance and responsible farming practices.
Before joining Growcycle, Victor worked for several agricultural and environmental publications, reporting on significant environmental issues and interviewing key figures in the sustainability sector. His work has been featured in various industry journals and online platforms.
