With its ability to bloom throughout the entire summer, withstand scorching heat, and resist diseases like powdery mildew, the BloomStruck® Bigleaf hydrangea’s enchanting beauty has captured the hearts of gardening enthusiasts far and wide. But what makes the BloomStruck® hydrangea truly extraordinary is its secret: the pH level of the soil determines its breathtaking color palette.
I. Appearance and Characteristics
A recent addition to the Endless Summer series, Hydrangea macrophylla Endless Summer® BloomStruck® is another exceptional mophead cultivar with medium-sized, rounded flower heads, up to 5 in. across (12 cm), densely packed with intense rose-pink, violet, or blue florets, depending on the soil pH.
Blooming on both old and new growth, this reblooming hydrangea blooms consistently and provides gorgeous flowers all summer long, as flower buds are produced not only in the fall but also in spring and summer. The flowers are borne on strong, upright, ruby-red stems, adding to this plant’s striking presence. Equally handsome, the foliage of large, serrated, dark green leaves is adorned with red petioles and red veins. It turns reddish purple in the fall, extending the season of interest of this hydrangea.
Exceptionally cold, hardy, with good heat tolerance and great disease resistance, especially to powdery mildew, ‘Bloomstruck’ is perfect as a specimen or in small groupings anywhere in the landscape that gets morning or filtered sun.
II. How to Grow and Care
Sunlight
BloomStruck hydrangeas are nature’s delicate darlings, and finding the perfect balance of sunlight is key to their well-being. Partial afternoon shade offers a gentle compromise, allowing them to bask in the warmth of sunlight while benefiting from the shade’s protective embrace.
In regions with northern climates, where the sun’s rays can be more intense, these resilient shrubs can handle full sun exposure as long as their soil is kept evenly moist.
This crucial moisture retention is vital to prevent the plants from wilting or experiencing stress during periods of heat. However, if achieving consistent soil moisture becomes a challenge, providing filtered sunlight or partial shade will shield the hydrangeas from excessive sunlight, ensuring their long-lasting vibrancy and vitality.
Temperature and Humidity
When it comes to temperature extremes, hydrangeas showcase their tolerance. Being a bit winter-hardy, they can withstand frosty conditions without harm. And since they are also heat tolerant, they can also thrive in hotter climates if given appropriate shelter or protection from intense sunlight.
By offering shade or a sheltered position during the hottest part of the day, we can ensure the plant thrives even in scorching conditions.
Hydrangeas, in general, thrive in environments with average to high humidity levels. When grown outdoors, the natural ambient moisture is typically sufficient for the well-being of flowers. However, if we choose to cultivate hydrangeas indoors as houseplants, additional measures are necessary to maintain the desired humidity levels.
Misting the leaves, using a humidifier, or placing the plant on a tray of pebbles filled with water can effectively raise the humidity and create an optimal environment for the hydrangeas to bloom.
Watering
Proper watering is a vital component of nurturing the BloomStruck hydrangea’s graceful growth. When cultivated in partial shade, particularly in the northernmost regions of its hardiness, this shrub maintains average water needs.
In general, providing about one inch of water per week is sufficient. However, it’s important to water only when the soil has dried out, as overwatering can impede blooming. Mulching the soil can prove beneficial, as it helps retain moisture and keeps the shrub hydrated.
Soil
Moist soil with the right pH level is the secret behind growing Hydrangea macrophylla. When the soil pH dips below 5.5, these remarkable shrubs unfurl delicate petals in stunning shades of blue. As the soil pH rises within the range of 5.5 to 6.5, the hydrangea flowers transition to a delightful palette of purple.
When the pH surpasses 6.5, the blooms take on a majestic reddish tone.
It may also be beneficial to enrich the soil as you go about improving its drainage. This can be achieved by incorporating generous amounts of decomposed organic matter. By adding compost, leaf mold, or well-rotted manure, you can enhance the soil’s structure and moisture-retention capabilities.
The organic matter also acts as a source of essential nutrients, nurturing the plants from their roots. As a result, the soil becomes a thriving habitat for beneficial microorganisms, fostering a harmonious environment for the plants to grow and thrive.
Fertilizing
Hydrangeas like fertile soil; enrich the growing medium annually with compost or manure tea. Or, you can apply an all-purpose, balanced fertilizer like 10-10-10 NPK once early to mid-spring and then every three months or so (suspend feeding in winter).
To increase the size and quantity of hydrangea blooms, use a fertilizer that contains a higher percentage of phosphorus. On a fertilizer bag, phosphorus is the middle number, so a fertilizer labeled 10-20-10 contains twice as much phosphorus as it does nitrogen and potassium.
If exploring slow-release granular fertilizers, choose a product where you see the term bloom booster because it probably contains a higher level of phosphorus. Too much nitrogen can result in lush foliage but fewer blooms.
Pruning
BloomStruck hydrangeas bloom on both old and new growth, so technically, they do not require pruning at all. However, if you do prune them, do so in the spring4 as the winter chill starts to ease up. You can prune down to the base, reenergizing the plant to grow healthy and bloom again in the summer. You should always remove stems that are dead, damaged, or diseased.
To prune BloomStruck during the summer, cut one or two of the oldest stems down to the base to encourage fullness and branching. If your plant is in zone 4 or 5, prune very little, and if you feel you need to, do it immediately after blooming.
It’s important to know that other types of hydrangeas have varying pruning requirements depending upon when they set their buds for next year’s flowers.
Propagation
As a trademarked cultivar, propagating BloomStruck hydrangeas for sale is prohibited. However, most hydrangeas are easy to propagate from cuttings. The best time to propagate is in the early fall. This plant will not be harmed when you take cuttings. You can root cuttings in soil or water.
You’ll need sterilized pruning snips, well-draining potting soil, an eight or 10-inch pot, rooting hormone, or a clear glass of water. Here’s how to do it:
- Using a sterilized set of pruning snips, clip off a healthy six- to eight-inch stem that does not have flowers.
- Cut just below a leaf node (where leaves grow from the stem). Keep the topmost set of leaves on the stem, removing the remainder.
- Dip the cut-end in rooting hormone.
- Push the cut-end into a pot filled with damp potting soil.
- Cover the pot with a clear plastic bag and close it at the bottom. Do not let the bag touch any of the leaves. You can cut a few slits at the sides of the bag or open the bag an hour each day for air circulation.
- Maintain moist soil by misting or watering frequently.
- Place the pot in a warm spot but not in direct sunlight.
- The cutting should root within two to four weeks. You’ll know it has roots if you see new growth, and when you gently tug the stem, you feel resistance. Once it’s developed roots, it’s ready to transplant.
An alternative method is to place the cut end in a clear glass of filtered water placed in indirect light. Remove the bottom leaves up to the waterline. It might take much longer than rooting in soil—about two months or so. Replenish the water to maintain the same waterline every few days. Change the water every 10 to 14 days. Once the roots are one- to two- inches long, it’s ready to pot in well-draining potting soil.
How to Get to Bloom
Hydrangea flowers make good cut flowers, although they aren’t fragrant. Since they rebloom all summer, you can safely cut some stems without harming your plant. But, be extra careful when pruning. Hydrangeas begin forming the buds for next year’s blooms shortly after blooming. Sometimes you can mistakenly prune off next year’s blooms. Over-pruning is a common reason why BloomStruck hydrangeas don’t bloom.
If your hydrangeas are not blooming, it could be incorrect pruning, damage to buds during the winter, or overfertilization of the plant. You can deadhead after flowers fade to encourage new buds.
Potting
When it comes to cultivating hydrangeas in containers, providing the right soil composition is paramount. These plants thrive in loose, pliable soil that offers excellent drainage and ample aeration. To achieve this, you have two options: using a well-draining potting mix or a blend of all-purpose potting soil mixed halfway with perlite or peat moss.
Both choices ensure a conducive environment for the growing zones of Hydrangea macrophylla once planted.
Terracotta pots prove to be an ideal choice for growing hydrangeas in containers. Their porous nature allows for water absorption, creating a welcoming and balanced growing environment even summer long. When repotting a hydrangea, opt for a pot that is one or two sizes larger than the current one, providing ample space for root growth.
It’s advisable to select a pot with a wide, flat base as hydrangeas can become top-heavy. The broad base offers stability and minimizes the risk of tipping over in windy conditions.
Overwintering
Under extreme weather conditions, some bigleaf hydrangeas will not bloom or will bloom poorly because of plunging temperatures, sudden or wide temperature fluctuations, icy conditions, or late frosts. Although BloomStruck hydrangeas can survive in USDA zone 4 temperatures, they are only winter hardy when they have protection in zones 4 to 6.
In those cold climates, protect your plants with shelter from harsh winds, which might be a burlap wrap or a circle of chicken wire filled with leaves or straw to a depth of eight- to 12-inches.
Here are some additional tasks to add to your Endless Summer hydrangea winter checklist5 :
- Stop fertilizing by mid-summer (end of July)
- Stop pruning in the fall
- Continue to water until frost
- Insulate roots with mulch
- Move container-grown plants to an unheated garage or shed
Pests and Diseases
One of the key factors that exacerbate plant diseases in Hydrangea is poor air circulation. When the gentle caress of the breeze is hindered, leaf spots, bacterial wilt, and bud blight find fertile ground to wreak havoc. These plant diseases thrive in stagnant environments, where moisture lingers and creates a breeding ground for their destructive presence.
Add to this, fungal infections are another relentless foe that seizes the opportunity to compromise plants. Yet by fostering a culture of prevention and care, healthy plants can ward off the encroachment of diseases. It begins with ensuring adequate air circulation, allowing the soothing whispers of the wind to brush through the foliage and prevent the stagnation that diseases thrive upon.
Furthermore, vigilance against common pests becomes paramount, as early detection and prompt intervention can shield these delicate blooms from harm. Regular inspections and the implementation of suitable pest management strategies can serve as a shield against unwanted invaders.
Fungal infections, too, can be kept at bay by practicing good hygiene and employing preventive measures. Proper watering techniques that avoid overhead irrigation and promote well-drained soil can minimize the conditions conducive to fungal growth.
III. Uses and Benefits
This hydrangea is pretty when used as a foundation planting or as a hedge. You can also plant BloomStruck® in containers or your cutting garden, as these flowers make excellent additions to your bouquets.
