The Tough, Dependable Bluebird Mountain Hydrangea
Don’t Be Fooled By the Frills. This Bluebird Means Business!
The Bluebird mountain hydrangea (Hydrangea serrata ‘Bluebird’) is a compact, upright deciduous shrub in the Hydrangeaceae family.
Native to the mountainous regions of Korea and Japan, it thrives in cool, moist, well-drained soil that mimics its natural habitat.
This vigorous grower produces delicate lacecap flowers in shades of periwinkle blue to purple-pink, depending on soil pH.
The lacey, flat-topped blooms appear in June and last through September, with large, sterile outer florets surrounding tiny fertile inner flowers.
In fall, Bluebird delivers brilliant red foliage, making it one of the best hydrangeas for autumn color.
Mountain hydrangeas, including Bluebird, are an excellent option for gardeners concerned about late winter or early spring frost.
Unlike bigleaf hydrangeas, they stay dormant longer and bloom later, reducing the risk of frost-damaged flower buds in regions with fluctuating spring temperatures.
Bluebird grows well in USDA zones 5–9 and reaches 4 to 6 feet in height and width. It performs best in part shade, with protection from the hot afternoon sun.
Compared to bigleaf hydrangeas, mountain hydrangea types are more tolerant of heat and humidity and are less prone to wilting, thanks to their smaller leaves.
This cultivar is relatively resistant to pests and diseases but may develop fungal issues if overwatered.
Like other hydrangeas, its flower color changes with soil pH: acidic soils produce blue blooms, while alkaline soils result in pinker hues.
To adjust the color, add garden sulfur for blue or garden lime for pink. Be patient, though, since changes may take several months to appear!
The Bluebird mountain hydrangea has lacecap flowers comprised of tiny, fertile inner flowers surrounded by larger sterile flowers.
How to Plant and Grow Bluebird Mountain Hydrangea
Planting: The best time of year to plant a mountain hydrangea is in the spring or fall, giving the roots time to establish before the onset of extreme hot or cold weather. Water deeply immediately after planting.
Location: Choose a location with well-drained soil that is rich in organic matter. Mountain hydrangeas prefer soil that retains moisture but does not become waterlogged. Select a spot with partial shade - while mountain hydrangea can tolerate full sun, it prefers part shade and protection from the intense afternoon sun.
Soil: Amend the soil with organic matter, such as compost, shredded leaves, or Leaf-gro®, to improve drainage and soil fertility. If you would like your mountain hydrangea to bloom specifically pink or blue, consider getting a soil test and adding either sulfur or lime to the soil. Add sulfur for blue flowers and lime for pink blooms.
Mulch: Apply a layer of organic mulch around the base of the plant to retain soil moisture, regulate temperature, and suppress weeds.
Watering: Keep the soil consistently moist but not waterlogged, especially during periods of drought. Deep watering is preferable to encourage the development of a strong root system (Are you in a drought? Check the U.S. Drought Monitor).
Fertilization: Hydrangeas typically do not need fertilization when they are given the rich, fertile soil they prefer. Each spring, spread a layer of compost, shredded leaves or Leaf-gro® around the base of your hydrangea, being careful to keep it away from the base of the shrub.
Pruning: Mountain hydrangeas bloom on old wood and look their best with minimal pruning. If needed, prune to shape in late summer when flowering has finished. Avoid pruning in fall, winter, or early spring as you risk removing flower buds and diminished flowering. Do not cut back mountain hydrangeas in the fall.
Pest and Diseases: Mountain hydrangeas are relatively pest resistant; aphids are an occasional problem. Mountain hydrangeas are prone to powdery mildew and leaf spot - ensure good air circulation to minimize the risk of diseases, and practice good watering habits (see “How to Water your Plants” to brush up on your watering skills).
Bluebird mountain hydrangea grows 4-6 feet high and wide.
Do Bluebird Mountain Hydrangeas Like Sun or Shade?
Bluebird mountain hydrangeas thrive in part shade and like 2-4 hours of sunlight per day, preferably dappled or filtered light with protection from the intense hot afternoon sun.
In hot climates, providing them with morning sun and afternoon shade can help prevent their flowers and leaves from wilting and scorching.
In cooler regions, they may tolerate more sun, but protection from harsh afternoon sunlight is still recommended.
Landscaping Ideas for Bluebird Mountain Hydrangea
Mixed Border Planting: Create a mixed border planting with Bluebird mountain hydrangeas along with other complementary shade-loving plants such as astilbe, ferns, and Japanese forest grass. This will add layers of texture and color to your garden.
Woodland Garden: Incorporate Bluebird mountain hydrangeas into a woodland garden setting. Under the dappled shade of trees, these hydrangeas will thrive and provide a provide flowers all summer long.
Side Yard: Bluebird mountain hydrangea is perfect for filling up a corner of a cool, moist, shady side yard.
Accent Planting: Use mountain hydrangeas as accent plants to highlight certain areas of the garden. Planting near a water feature or along a pathway can draw attention to these beautiful shrubs.
Foundation Planting: Incorporate Bluebird mountain hydrangeas into your foundation planting to add visual interest and soften the lines of your home. They work well when paired with partial-shade loving evergreen shrubs like Himalayan sweetbox (Sarcococca hookeriana var. humilis) or spreading Japanese plum yew.
Mass Planting: Create a striking display by mass planting mountain hydrangeas in larger garden areas, like a shady slope or property line.
Soften Fence Line: Plant a row of mountain hydrangeas along the length of a fence to soften harsh lines or distract from a view of chain links.
Bluebird Mountain Hydrangea is perfect for planting in a cool, moist, shady side yard.