Hydrangea Macrophylla Merritt’S Supreme – Cultivating Dazzling Blooms
Dreaming of a garden bursting with colossal, colorful blooms? You’re in the right place! Few plants capture the imagination quite like the majestic hydrangea, and among its many enchanting varieties, hydrangea macrophylla ‘Merritt’s Supreme’ stands out as a true superstar. Its reliable flowering and stunning color display make it a favorite for both seasoned gardeners and those just starting their horticultural journey.
I know, sometimes hydrangeas can seem a little intimidating with all the talk about soil pH and pruning. But don’t worry—these flowers are perfect for beginners! This guide will walk you through everything you need to know to grow ‘Merritt’s Supreme’ with confidence, transforming your outdoor space into a vibrant sanctuary. Get ready to unlock the secrets to truly magnificent hydrangea blooms!
What's On the Page
- 1 Unveiling the Beauty of Hydrangea Macrophylla ‘Merritt’s Supreme’
- 2 Choosing the Perfect Spot: Location and Soil Requirements
- 3 Mastering the Art of Hydrangea Color: Soil pH
- 4 Planting Your Hydrangea Macrophylla ‘Merritt’s Supreme’
- 5 Ongoing Care: Watering, Fertilizing, and Pruning
- 6 Winter Protection for Hydrangea Macrophylla ‘Merritt’s Supreme’
- 7 Common Problems and Troubleshooting
- 8 Designing with ‘Merritt’s Supreme’: Garden Inspiration
- 9 Frequently Asked Questions About Hydrangea Macrophylla ‘Merritt’s Supreme’
- 10 Conclusion: Embrace the Beauty of ‘Merritt’s Supreme’
Unveiling the Beauty of Hydrangea Macrophylla ‘Merritt’s Supreme’
Let’s get acquainted with this garden gem. Hydrangea macrophylla, commonly known as Bigleaf Hydrangea or Mophead Hydrangea, is celebrated for its large, rounded flower heads. ‘Merritt’s Supreme’ takes this a step further, offering exceptionally large, deeply colored blooms that truly make a statement.
This particular cultivar is a reblooming type, meaning it flowers not only on old wood but also on new growth. This characteristic is a game-changer, especially in regions with colder winters where old wood might suffer frost damage. You’ll enjoy a prolonged flowering season from early summer right through to fall.
Key Characteristics of ‘Merritt’s Supreme’
Understanding what makes this plant special is the first step to successful cultivation.
- Flower Color: The blooms are typically a rich pink in neutral to alkaline soils and a vibrant blue in acidic soils. This color-changing ability is one of the most exciting features of Bigleaf Hydrangeas!
- Size: ‘Merritt’s Supreme’ usually grows to about 3-5 feet tall and wide, forming a dense, rounded shrub. Its compact size makes it versatile for various garden applications.
- Hardiness Zones: It thrives in USDA Hardiness Zones 5-9. In colder zones, some winter protection might be beneficial to ensure robust flowering.
- Foliage: The leaves are dark green, glossy, and provide an excellent backdrop for the spectacular flowers.
Choosing the Perfect Spot: Location and Soil Requirements
Just like finding the right home, selecting the ideal location for your hydrangea is crucial. These plants have specific preferences that, when met, lead to an abundance of blooms.
A little upfront planning goes a long way in ensuring your plant’s long-term health and vibrance.
Sunlight Exposure: Finding the Sweet Spot
Hydrangeas generally prefer a balance of sun and shade. Too much direct, intense sun, especially in hot climates, can scorch their leaves and cause flowers to fade quickly.
Conversely, too much deep shade can result in sparse flowering. For hydrangea macrophylla ‘Merritt’s Supreme’, aim for a spot that receives morning sun and afternoon shade.
- Morning Sun: 4-6 hours of gentle morning sunlight is ideal.
- Afternoon Shade: Protection from the harsh afternoon sun, particularly from 1 PM to 4 PM, is essential. This helps prevent wilting and keeps the plant hydrated.
- Full Shade? Avoid planting in full, dense shade. You’ll likely get more foliage than flowers.
Soil Composition and Drainage
Hydrangeas are not overly fussy, but they do appreciate well-draining soil that is rich in organic matter. Heavy clay soils that retain too much water can lead to root rot, while sandy soils may dry out too quickly.
Improving your soil before planting is one of the best investments you can make for your hydrangea.
- Drainage Test: Dig a small hole (about a foot deep) and fill it with water. If the water drains within an hour, your drainage is good. If it takes longer, you’ll need to amend.
- Amending Soil: Incorporate plenty of compost, well-rotted manure, or other organic materials into the planting area. This improves both drainage and water retention, creating a hospitable environment for roots.
- Soil pH: This is where the magic happens for flower color! More on this below.
Mastering the Art of Hydrangea Color: Soil pH
One of the most captivating aspects of Hydrangea macrophylla varieties like ‘Merritt’s Supreme’ is their ability to change flower color based on soil pH. This isn’t just a fun fact; it’s a tool you can use to customize your garden palette!
Understanding and managing soil pH is key to achieving your desired bloom color.
The Science Behind the Shades
The color of ‘Merritt’s Supreme’ flowers is determined by the availability of aluminum in the soil, which is directly influenced by pH.
- Acidic Soil (pH 5.5-6.0): In acidic conditions, aluminum becomes more available to the plant, resulting in beautiful blue flowers.
- Alkaline Soil (pH 6.5-7.0+): In more alkaline conditions, aluminum is less available, leading to lovely pink blooms.
- Neutral Soil (pH 6.0-6.5): You might get a mix of pink and blue, or even stunning purple shades, in neutral soil.
Adjusting Your Soil pH
Want to shift your pink blooms to blue, or vice versa? It’s entirely possible with a bit of effort and patience.
First, always start with a soil test. This will tell you your current pH level and nutrient composition, guiding your amendment strategy.
To Encourage Blue Blooms:
- Add Aluminum Sulfate: This is the most effective way to lower pH and increase aluminum availability. Follow package directions carefully, applying it in spring and early fall.
- Use Acidifying Fertilizers: Look for fertilizers formulated for acid-loving plants, often labeled for rhododendrons or azaleas.
- Incorporate Organic Matter: Peat moss or pine bark can help lower pH over time.
To Encourage Pink Blooms:
- Add Garden Lime: Apply dolomitic lime or hydrated lime to raise the soil pH. Again, follow product instructions diligently.
- Use High-Phosphorus Fertilizers: Phosphorus binds with aluminum, making it unavailable to the plant, thus promoting pink flowers.
- Avoid Aluminum Sulfate: Naturally, if you want pink, don’t add anything that promotes blue.
Remember, changes won’t happen overnight. It can take several months, or even a full growing season, to see a noticeable shift in flower color. Be patient and consistent!
Planting Your Hydrangea Macrophylla ‘Merritt’s Supreme’
Once you’ve chosen your spot and prepared your soil, it’s time for the exciting part: planting! Proper planting techniques ensure a strong start for your new shrub.
Always plant during cooler parts of the day, preferably in spring or fall, to minimize transplant shock.
Step-by-Step Planting Guide
- Dig the Hole: Excavate a hole that is twice as wide as the root ball and just as deep. The top of the root ball should be level with or slightly above the surrounding soil.
- Inspect the Roots: Gently remove the plant from its container. If the roots are circling tightly, tease them apart with your fingers or make a few vertical cuts with a clean knife.
- Position the Plant: Place the hydrangea in the center of the hole, ensuring it’s upright.
- Backfill: Carefully backfill the hole with the amended soil, gently tamping it down to remove air pockets. Avoid burying the crown of the plant too deeply.
- Water Thoroughly: Give your newly planted hydrangea a deep, thorough watering. This helps settle the soil around the roots.
- Mulch: Apply a 2-3 inch layer of organic mulch (like pine bark, shredded leaves, or compost) around the base of the plant, keeping it a few inches away from the stem. Mulch helps retain moisture, regulate soil temperature, and suppress weeds.
Ongoing Care: Watering, Fertilizing, and Pruning
With your ‘Merritt’s Supreme’ settled in, consistent care will ensure it flourishes year after year. These maintenance tasks are straightforward and vital for healthy growth and abundant blooms.
Think of it as providing regular nourishment and grooming for your garden’s star performer.
Watering Your Bigleaf Hydrangea
Hydrangeas are thirsty plants, especially when establishing and during hot, dry periods. The name “hydra” in hydrangea gives you a clue!
- Consistency is Key: Aim for consistent moisture. Don’t let the soil dry out completely, but also avoid waterlogging.
- Deep Watering: Water deeply and slowly at the base of the plant, rather than frequent, shallow sprinkles. This encourages deep root growth.
- Frequency: Young plants may need watering every day or two, while established plants might only need it once or twice a week, depending on weather and soil type. Wilting leaves are a clear sign it needs a drink.
Fertilizing for Peak Performance
Fertilizing helps provide the nutrients your hydrangea needs to produce those magnificent flowers. However, too much fertilizer can lead to lush foliage at the expense of blooms.
A balanced approach is best.
- When to Fertilize: Apply a slow-release granular fertilizer in early spring as new growth emerges. A second, lighter application can be done in mid-summer if needed, but avoid fertilizing late in the season, which can stimulate tender new growth susceptible to frost.
- Type of Fertilizer: For blue blooms, use a fertilizer with a higher potassium content and low phosphorus, or one specifically formulated for acid-loving plants. For pink blooms, choose a fertilizer higher in phosphorus.
- Avoid Over-Fertilizing: Always follow package directions. More is not better and can burn the roots.
Pruning ‘Merritt’s Supreme’ for Optimal Blooms
Pruning Bigleaf Hydrangeas can be tricky because many varieties bloom on “old wood” (last year’s growth). However, since ‘Merritt’s Supreme’ is a rebloomer, it’s more forgiving.
The general rule of thumb for reblooming hydrangeas is minimal pruning.
- Deadheading: Remove spent flowers (deadhead) to encourage more blooms and keep the plant looking tidy. Cut the spent flower stem back to the first set of healthy leaves or a strong bud.
- Structural Pruning (Late Winter/Early Spring): Remove any dead, damaged, or weak stems. You can also selectively remove a few of the oldest, thickest stems at the base to encourage new, vigorous growth. Do this before new growth fully emerges.
- Shape Pruning: If the plant is getting too large or leggy, you can prune to shape it, but remember that heavy pruning will reduce early-season blooms. Since it reblooms, you’ll still get flowers later in the season.
Winter Protection for Hydrangea Macrophylla ‘Merritt’s Supreme’
While ‘Merritt’s Supreme’ is relatively hardy, providing some winter protection, especially in USDA Zones 5 and 6, can safeguard the flower buds on old wood and ensure a spectacular display the following summer.
A little extra care in the fall can prevent a lot of disappointment come spring.
Steps for Winterizing Your Hydrangea
- Stop Fertilizing: Cease all fertilization by late summer to prevent new, tender growth that won’t harden off before winter.
- Mulch Heavily: In late fall, after the ground has frozen, apply a thick layer (6-12 inches) of organic mulch around the base of the plant. Materials like shredded leaves, straw, or pine needles work well. This insulates the crown and roots.
- Protect Stems (Optional): In very cold zones, you might consider wrapping the entire plant with burlap or creating a cage filled with leaves around it. This protects the above-ground stems and their precious flower buds from harsh winds and extreme cold.
- Avoid Early Pruning: Do not prune in fall or early winter, as this removes potential flower buds for the next season.
Common Problems and Troubleshooting
Even the most experienced gardeners encounter issues. Knowing how to identify and address common problems will help keep your hydrangea macrophylla ‘Merritt’s Supreme’ thriving.
Most problems are easily fixable with a bit of observation and prompt action.
No Blooms or Few Blooms
This is a common frustration, but usually has a clear cause.
- Incorrect Pruning: If you pruned too heavily in fall or early spring, you might have removed the old wood flower buds. Remember ‘Merritt’s Supreme’ blooms on both old and new wood, but old wood provides the earliest flush.
- Winter Damage: Severe cold snaps can kill flower buds on old wood. This is where winter protection really helps.
- Too Much Shade: Insufficient sunlight will result in leggy growth and sparse flowering.
- Over-Fertilizing Nitrogen: Too much nitrogen promotes leafy growth at the expense of flowers.
Pests and Diseases
Hydrangeas are generally robust, but can occasionally face challenges.
- Aphids: Small, soft-bodied insects that cluster on new growth. They can be dislodged with a strong spray of water or treated with insecticidal soap.
- Spider Mites: Tiny pests that thrive in hot, dry conditions. Look for fine webbing on the undersides of leaves. Increase humidity and use insecticidal soap.
- Powdery Mildew: A white, powdery coating on leaves, often occurring in humid conditions with poor air circulation. Ensure good spacing between plants and avoid overhead watering. Treat with a fungicide if severe.
- Leaf Spot: Various fungal spots can appear on leaves. Remove affected leaves and ensure good air circulation.
Regular inspection of your plants will help you catch any issues early before they become severe.
Designing with ‘Merritt’s Supreme’: Garden Inspiration
Beyond its individual beauty, hydrangea macrophylla ‘Merritt’s Supreme’ is a fantastic plant for various garden design applications. Its vibrant color and substantial size make it a focal point.
Let your creativity bloom as you integrate this versatile shrub into your landscape.
Ideas for Incorporating Hydrangeas
- Foundation Planting: Its rounded shape and manageable size make it perfect for planting along house foundations, adding curb appeal.
- Mixed Borders: Combine with other shrubs, perennials, and annuals that enjoy similar light and soil conditions. Think hostas, ferns, astilbe, or impatiens for companion planting.
- Specimen Plant: Allow it to shine on its own as a standalone feature in a prominent spot.
- Container Gardening: In colder zones, ‘Merritt’s Supreme’ can be grown in large containers and moved to a sheltered location or unheated garage for winter protection. Ensure excellent drainage and use a high-quality potting mix.
- Cut Flowers: The large, long-lasting blooms are absolutely stunning in floral arrangements. Cut stems in the morning after dew has dried.
Frequently Asked Questions About Hydrangea Macrophylla ‘Merritt’s Supreme’
What is the best time to plant ‘Merritt’s Supreme’ hydrangea?
The ideal times to plant are in the spring after the last frost or in the early fall, allowing the roots to establish before winter. Avoid planting during the hottest part of summer.
How often should I water my ‘Merritt’s Supreme’ hydrangea?
During its first year, water frequently, often daily, especially in hot weather, to help it establish. Once established, deep watering 1-3 times a week, depending on rainfall and temperature, is usually sufficient. Always check the soil moisture before watering.
Can I grow ‘Merritt’s Supreme’ in a pot?
Yes, ‘Merritt’s Supreme’ does very well in large containers (at least 18-24 inches in diameter). Ensure the pot has drainage holes and use a good quality potting mix. Remember that container plants dry out faster and will need more frequent watering and winter protection.
How do I make my pink ‘Merritt’s Supreme’ blue?
To encourage blue flowers, you need to lower the soil pH to make aluminum available. Apply aluminum sulfate in spring and early fall, following package instructions. You can also use acidifying fertilizers or incorporate peat moss. Perform a soil test first to know your current pH.
When should I deadhead my ‘Merritt’s Supreme’ blooms?
You can deadhead spent flowers at any time to improve the plant’s appearance and encourage more blooms. Simply cut the flower stem back to the first set of healthy leaves or a strong bud below the faded flower head.
Conclusion: Embrace the Beauty of ‘Merritt’s Supreme’
Growing hydrangea macrophylla ‘Merritt’s Supreme’ is a truly rewarding experience. With its magnificent, color-changing blooms and relatively easy care, it’s a fantastic choice for adding vibrant beauty to any garden. By providing the right location, nurturing the soil, and offering consistent care, you’ll be treated to a spectacular display that lasts for months.
Don’t be afraid to experiment with soil pH to achieve your desired pink or blue hues, and enjoy the process of watching your garden transform. These hydrangeas are resilient and generous, ready to bring joy and color to your outdoor space. Go forth and grow—your garden is about to become a masterpiece!
