Cover Image credit: Bailey Nurseries

Showy Lacecap Flowers Bloom on Old and New Wood

Endless Summer® Twist-n-Shout® Reblooming Hydrangea (Hydrangea macrophylla ‘PIIHM-I’) is a cultivated variety of the bigleaf hydrangea, a deciduous shrub from Asia, belonging to the Hydrangeaceae family.

Twist-n-Shout® is part of the Endless Summer® collection of reblooming hydrangeas, and has the distinction of being the world’s first reblooming lacecap hydrangea.

It has the ability to bloom on both old and new wood and flowers repeatedly from late spring through fall, despite extreme winter cold snaps and unpredictable spring freezes.

Twist-n-Shout® has showy lace cap flowers in either periwinkle blue or deep pink, depending on the soil pH.

In late spring to early summer the first round of flowers appears, originating from buds produced on old wood.

After a brief rest, flowers continue emerging from buds created on new wood, and waves of flowers continue all summer long.

Twist-n-Shout® hydrangeas come with the added bonus of strong, vivid red stems and beautiful fall color.

In autumn, the dark green serrated leaves turn shades of red, burgundy, purple and yellow.

hydrangea planted in container with blue lacecap flowers next to wicker couch with orange cushions and rug — Endless Summer® Twist-n-Shout® Reblooming Hydrangea. Image courtesy of Bailey Nurseries.

In winter, dried flower heads remain on the plant and provide winter interest in the garden.

Twist-n-Shout® is a moderately fast-growing hydrangea, adding up to 24 inches of growth per year and eventually reaching 3-5 feet in height and 3-4 feet in width.

Twist-n-Shout® grows in zones 4-9, and prefers part shade and rich, well-draining soil.

Partial shade is important since these hydrangeas can be sensitive to intense sun exposure, particularly in the afternoon.

Deer will eat hydrangea flower buds and leaves, especially the tender young growth.

If you would like to grow a flowering shrub that deer tend to leave alone, try Ruby Spice summersweet clethra as a deer resistant alternative to the bigleaf hydrangea.

What is a Reblooming Hydrangea?

A reblooming hydrangea blooms on both old and new wood, giving it the ability to produce flowers repeatedly throughout the growing season.

The Twist-n-Shout® hydrangea produces its first flush of blooms from buds that were set in the previous year.

After a short break, subsequent flowers emerge later in the summer from buds that form on the current season’s growth.

Reblooming hydrangeas are also called remontant hydrangeas.

hydrangea bush with blue lacecap flowers and green leaves in landscape — The lacecap flowers of Twist-N-Shout® hydrangea are comprised of tiny fertile flowers surrounded by showy sterile florets. Image courtesy of Bailey Nurseries.

How to Plant and Grow Twist-n-Shout® Reblooming Hydrangea

Planting: The best time of year to plant a Twist-n-Shout® 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. Twist-n-Shout® prefers soil that retains moisture but does not become waterlogged. Select a spot with partial 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 Twist-n-Shout® 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. Make sure the mulch does not touch the base of the plant.
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 away from the base of the shrub.
Pruning: Twist-n-Shout® hydrangea requires little to no pruning - if you prune too much, you risk cutting off buds that will eventually become flowers. Cut out dead or damaged canes as needed.
Pest and Diseases: Twist-n-Shout® hydrangeas are prone to powdery mildew and cercospora leaf spot. Ensure good air circulation around your plants to minimize the risk of disease, and practice good watering habits (see “How to Water your Plants” to brush up on your watering skills).

Do Twist-n-Shout® Reblooming Hydrangeas Like Sun or Shade?

The Twist-n-Shout® Reblooming Hydrangea thrives in partial shade and does best with 2-4 hours of direct sunlight per day.

While it can tolerate more sun, Twist-n-Shout® prefers dappled or filtered light, with protection from the intense hot afternoon sun.

In hot climates, providing Twist-n-Shout® hydrangea with morning sun and afternoon shade can help prevent flowers and leaves from wilting and scorching.

In cooler regions, they may tolerate more sun, but protection from harsh afternoon sunlight is still recommended.

Planting Companions for Twist-n-Shout® Hydrangea

Feeling inspired to plant a Twist-n-Shout® hydrangea in your garden? Here are some ideas for planting companions - all favor the same partial shade conditions and moist, rich, well-draining soil that bigleaf hydrangeas love:

NewGen Independence® Boxwood (Buxus NewGen Independence® ‘SB 108’): The small evergreen leaves and structured shape of boxwoods are the perfect foil for the larger leaves and loose form of the bigleaf hydrangea. NewGen Independence® has a rounded habit and improved resistance to boxwood leafminer.
Cavatine Japanese Andromeda (Pieris japonica ‘Cavatine’): Striking evergreen leaves and delicate, bell-shaped white flowers contrast nicely with the large leaves of the hydrangea.
Delaware Valley White Azalea (Rhododendron ‘Delaware Valley White’): The white flowers and dark green foliage of this evergreen azalea won’t clash with the blue or pink flowers of Twist-n-Shout®.
Tater Tot® Arborvitae (Thuja occidentalis 'SMNTOBABA’ Tater Tot®): A row of these petite, 12-24 inch high globe-shaped evergreens can be planted in front of a row of Twist-n-Shout® hydrangeas, creating a pleasing textural contrast.

Astilbe (Astilbe species): The fine textured foliage and spiky summer flowers of astilbe are the perfect partner for Twist-n-Shout®. White varieties like ‘Deutschland’ look particularly nice.
Golden Variegated Hakone Grass (Hakonechloa macra ‘Aureola’): Striking, fine-textured foliage contrasts nicely with the large leaves and globe-shaped flowers of bigleaf hydrangeas.
Jack Frost Siberian Bugloss (Brunnera macrophylla ‘Jack Frost’): Small airy blue flowers rise above the silvery-green foliage of this shade-loving, 12-15 inch tall perennial.
Japanese Painted Fern (Athyrium niponicum 'Pictum'): Dramatic blue-green-silver foliage, a short stature and spreading form make this a great choice for planting next to a Twist-n-Shout® hydrangea.

Garden Ideas for Twist-n-Shout® Reblooming Hydrangea

Foundation Planting: Plant Twist-n-Shout® along side the foundation of your house. Its lush green foliage and colorful blooms will enhance the curb appeal of your home.
Mixed Borders: Create a mixed border planting by combining Twist-n-Shout® with other complementary perennials, ornamental grasses, and evergreen shrubs for four seasons of visual appeal.
Mass Planting: Plant Twist-n-Shout® hydrangeas in groupings to create a mass of color. This approach works well in large garden beds or alongside pathways and fences, providing a striking visual impact.
Woodland Garden: The dappled shade underneath the canopy of tall trees is an ideal spot for the Twist-n-Shout® hydrangea. Combine with other partial-shade loving plants like camellias, Japanese andromeda, azaleas, and rhododendrons.
Accent Planting: Use Twist-n-Shout® as a focal point in the landscape. Plant strategically to draw attention to specific areas of the garden, like entryways, water features, pathways, or seating areas.
Vintage Cottage Garden: For a charming, informal look, plant Twist-n-Shout® alongside old-fashioned cottage garden favorites like foxgloves, garden phlox, hollyhocks, catmint, hibiscus, and roses.

pink lacecap hydrangea flower closeup — Twist-n-Shout® reblooming hydrangeas have pink flowers in alkaline soil. *Image credit: Bailey Nurseries*

How to Change the Color of Twist-n-Shout® Reblooming Hydrangea

You can change the color of your hydrangea blooms by manipulating the pH of the soil.

The pH level affects the availability of aluminum in the soil, in turn influencing the color of hydrangea flowers.

Adding aluminum sulfate, garden sulfur, or organic matter makes the soil more acidic and will turn the color of hydrangea blooms an intense blue.

In neutral soils, both blue and pink flowers may be present on the plant at the same time.

Adding garden lime raises the soil pH and turns blooms pink. Be patient - it can take months for change to become evident!

Are Twist-n-Shout® Reblooming Hydrangeas Poisonous to Dogs?

Twist-n-Shout® Reblooming Hydrangeas (Hydrangea macrophylla ‘PIIHM-I’) contain compounds that can be toxic to dogs if ingested, specifically cyanogenic glycosides.

These compounds can release cyanide when broken down in the digestive system.

However, the level of toxins in bigleaf hydrangeas are relatively low, and instances of dogs getting poisoned by consuming these plants are rare.

While the risk of severe poisoning is low, it’s important to monitor your dog's behavior in outdoor spaces.

If you suspect your dog has ingested a toxic plant, seek immediate veterinary care or contact the Pet Poison Hotline.

Read “Which Plants are Toxic to Dogs” for more information on plants poisonous to dogs.

Why isn’t My Twist-n-Shout® Hydrangea Blooming?

It can be quite disappointing when your Twist-n-Shout® hydrangea fails to bloom, especially when you've been eagerly anticipating its striking lacecap flowers. Several factors could contribute to its lack of blooms:

Improper pruning: Twist-n-Shout® hydrangeas bloom on both old and new wood. Overzealous pruning runs the risk of cutting off flower buds that will eventually become flowers. Twist-n-Shout® hydrangeas requires little to no pruning - cut out dead or damaged canes as needed.
Young plant: Hydrangeas may take a few years to establish before they start blooming. If your plant is still relatively young, it might just need more time to mature and establish itself - be patient!
Insufficient sunlight: For best flowering, Twist-n-Shout® hydrangeas need at least 2-4 hours of direct sunlight per day. If they're not getting enough sunlight, they may produce fewer blooms or fail to bloom altogether.
Watering issues: Inconsistent or inadequate watering can stress the plant and affect flowering. Ensure your hydrangea receives sufficient water, especially during hot and dry periods.
Deer: Deer like the taste of hydrangeas, particularly the flowers and buds. They may visit your yard and nibble the buds off of your hydrangea, leaving no evidence of their presence other than the absence of flowers.