How to Plant, Grow, and Care for ‘Endless Summer’ Hydrangeas

Endless Summer hydrangeas showcase the classic mophead hydrangea blooms we need in our gardens. This hardy collection of hydrangeas spans growing zones with reliable reblooming and long-lasting seasonal color. Explore the merits of an ‘Endless Summer’ with gardening expert Katherine Rowe.

The Endless Summer Hydrangea features large, glossy green leaves and abundant, rounded clusters of vibrant blue and pink flowers.

Contents

Endless SummerⓇ hydrangeas feature big, bold blooms in rich blue, pink, violet, and white with the classic mophead flower clusters we adore in hydrangeas. Glossy foliage provides a lush backdrop to the prolific blooms.

Endless SummerⓇ is an exceedingly popular collection of hydrangeas, prized for their garden performance and showy blooms. Endless SummerⓇ The Original (the first in the series) boasts unique qualities of repeat flowering and cold hardiness among bigleaf hydrangea types. These beauties flower all season (hence, “endless”) for an extended bloom time with lasting color and visual appeal.

Overview

A large, lush Endless Summer hydrangea bush with heart-shaped dark green leaves and plentiful, globe-shaped blooms in delicate shades of purple, pink and blue.
Plant Type Perennial shrub
Plant Type Perennial shrub
Family Hydrangeaceae
Genus Hydrangea
Species macrophylla
Native Area Garden origin
Exposure Partial shade
Height 3-6’
Watering Requirements Average
Pests & Diseases Aphids, powdery mildew, leaf spot, bacterial wilt, deer
Soil Type Average
Hardiness Zone 4-9

What are Endless SummerⓇ Hydrangeas?

Hydrangea Endless Summer Bailmer boasts broad, shiny leaves and voluminous, mophead flowers in a delicate pink hue.
Reblooming hydrangeas with vibrant colors, perfect for shady gardens.

This series contains a collection of six varieties of reblooming bigleaf hydrangeas. They feature attractive mophead blooms (rounded flower clusters) in rich blues, pinks, purples, magenta, and white. Hydrangea macrophylla ‘Bailmer’ The Original is the first hydrangea bred to bloom on both old and new wood, offering extended hydrangea bloom time, increased flowering, and reblooming from early summer to frost.

Endless SummerⓇ hydrangeas are unique in this old and new wood flowering combination and their cold-hardiness among bigleaf selections. They are hardy down to USDA zone 4, and their ability to bloom on old and new wood ensures flowering even if extreme winter conditions impact old wood buds.

Endless SummerⓇ The Original hydrangeas grow upright with a rounded form. They reach three to four feet tall and wide and have lush, full foliage. With their profusion of blooms and leafy backdrops, these shrubs make exceptional mass plantings, hedges, foundation plantings, accents, and specimen plants. 

Pair them with shade-loving perennials like hosta, ferns, astilbe, and hellebore for gorgeous multi-season combinations. They grow beautifully with roses in cooler climates where they tolerate more sun or with roses that tolerate partial shade.

Endless Summer is a low-maintenance, easy-care selection that grows in partial to full shade, depending on climate. They’re durable shrubs with multi-season appeal, and cultivars in unique colors and forms bring excitement to any shady garden spot.

Characteristics

Close-up of a lush hydrangea bush with large, heart-shaped dark green leaves with finely serrated edges and large, spherical flower clusters in striking blue and pink hues.
Endless Summer hydrangeas bring year-round beauty and resilience.

Hydrangea macrophylla ‘Bailmer’, sold as Endless SummerⓇ The Original, changed the landscape by giving the classic bigleaf hydrangea a broader growing range and the capacity to rebloom. Cold-hardy and heat-tolerant (to zone 9), it withstands various climate conditions across most growing zones. Hydrangeas are, by nature hardy shrubs, but the old wood/new wood bud development opens the flowering range.

Hydrangeas that bloom on old wood (the previous year’s growth) set their buds for the next season in late summer and early fall. In very cold climates, this exposes young buds to potential winter damage and subsequent loss of flowering in the following seasons. Hydrangeas that bloom on new wood (the current year’s growth) develop buds in the spring before blooming. Endless Summer’s ability to set buds on old wood and continue budding on new growth means blooms galore in optimal growing conditions, even if old buds don’t withstand winter.

The showiest characteristic of this vigorous hydrangea is its luscious blooms. The large, rounded flowers are white or a rich, cool blue or delicate pink, depending on the soil pH. Acidic soils produce bluer flowers, while alkaline soils yield pinker blooms. You can adjust your soil pH to get either blue or pink blooms by adding aluminum sulfate for blue or lime for pink (see the “Soil” section for details). Soil pH levels don’t impact white Endless Summer cultivars.

As a bigleaf hydrangea, Endless SummerⓇ features large, glossy, deep green, serrated leaves to complement its bountiful mophead flower clusters. Small fruit capsules emerge after flowering. Foliage turns burgundy red in fall and adds seasonal interest. Flowers left on the plant persist in dried form into winter.

Endless SummerⓇ hydrangeas are generally disease-resistant plants. With essential cultural growing requirements met, they’re long-lived garden performers.

Native Area

Close-up of a flowering plant Hydrangea macrophylla Endless Summer with deep green, glossy leaves and prolific, rounded flower heads in delicate shades of blue and purple.
Hydrangeas, born from Asian woodlands, bloom endlessly in gardens.

Bigleaf hydrangeas are native to Asia. They grow in woodlands along stream banks and rocky areas on the seaside and mountains of Japan, Korea, China, and Southeast Asia.

Endless Summer hydrangeas are hybrid cultivars bred and trademarked by Bailey Nurseries in Minnesota in collaboration with renowned plantsman Dr. Michael Dirr of the University of Georgia. The Original came into cultivation in 2004 after years of trialing a novel reblooming and hardy hydrangea from the yard of a Minnesota schoolteacher. This introduction led to the development of the Endless SummerⓇ collection.

Planting

Close-up of a female gardener wearing a denim shirt, brown pants and black gloves planting a flowering hydrangea plant in the soil in the garden.
Optimal planting timing and spacing ensure vibrant hydrangeas.

Fall and spring are the best time to plant hydrangeas. The mild conditions pose the least stress on new plants as they become established in the garden. For fall additions, don’t add fertilizer at planting time. Hydrangeas enter winter dormancy to conserve energy, and fertilizer counters this by encouraging new growth. Wait until spring to fertilize for the growing season. 

For best air circulation around plants, arrange Endless Summer so they’re nearly four feet from other plants. This hydrangea spacing allows room for mature growth, and plants may touch but won’t be overcrowded.

To plant Endless Summer hydrangeas, dig a rough hole larger than the size of the nursery pot. Gently loosen any tightly packed roots and place the plant in the hole. Hydrangeas benefit from a level crown rather than being planted too high or too low for best growth and flowering. Ensure the plant crown (where the base of the stems meets the roots) is at soil level when tucking plants in. Water new hydrangeas thoroughly at the plant’s base.

Endless Summer hydrangeas make excellent container features given plenty of water, a quality potting mixture, and appropriate light conditions. When planting, choose a container larger than the nursery pot. Add soil so the hydrangea is at least two inches below the pot’s rim, and infill accordingly.

Transplanting 

Close-up of a large hydrangea bush placed in a large wheeled cart, ready for replanting in the garden.
Transplant hydrangeas successfully by timing and thorough root care.

If you need to move a hydrangea to another garden location, it’s best to do so when plants are dormant. Late fall, even after frost, and late winter/early spring are optimal. Dig a wide berth and go deep around established plants to lift as many roots as possible for transplanting. Water deeply after installing the hydrangea in its new spot.

How to Grow

Endless Summer hydrangeas are carefree, unfussy plants with low maintenance requirements. However, they have specific cultural requirements that promote plant health and vigor, which relate to your garden’s climate and growing zone.

Light

Close-up of a flowering hydrangea bush with large lush mophead blooms in delicate shades of pink and blue under full bright sun in a garden.
Achieve optimal Endless Summer blooms with appropriate sunlight management.

These hydrangeas need sunlight to grow and bloom, but the amount of light they need depends on intensity. Morning sun with afternoon shade protection is ideal in most planting areas.

In northern growing areas with cool climates (like zones 4 and 5), they grow best in six hours of full sun as long as soil moisture is consistent. For hot, southern climates (zones 8 and 9), two to three hours of morning sun or dappled sunlight is sufficient.

In hot climates, intense sun can burn and scorch leaves and flowers. Provide afternoon protection from direct sunlight. The plants tolerate full shade in hot growing conditions.

Water

Watering a flowering hydrangea bush with soft blue and soft pink ball-shaped flower clusters and broad, dark green leaves using a blue watering can in the garden.
Keep hydrangeas thriving with consistent, mindful watering practices.

Hydrangeas, whose genus name comes from the Greek “hydor,” meaning water, need regular water to thrive. Bigleaf hydrangeas are among the thirstiest. About one inch of water per week is sufficient for Endless SummerⓇ hydrangeas. Water until frost to prepare hydrangeas for winter dormancy.

Even moisture ensures hydrangeas’ overall health and vigor, but too much water leads to a decline in flowering and fungal issues. Avoid overly wet and prolonged soggy conditions caused by irrigation. To check the soil’s moisture, the best test is to touch the soil and feel one to two inches below the surface. Wet soil means holding off on watering, and dry signals time to water.

Water hydrangeas in the morning (preferable) or evening to retain the most moisture before evaporation. Watering deeply, rather than frequently and shallowly, is best for root growth and moisture uptake.

Watering hydrangeas at the plant’s base avoids splashing the leaves and is best for preventing the spread of fungal and bacterial diseases. Drip irrigation, soaker hoses, or direct hand watering accomplish this. Use spray heads or overhead irrigation early in the day, so plants have a chance to dry out.

For Endless Summer growing in pots, ensure the containers are well-draining. Containers dry out fast in the heat of summer, so be sure to check soil moisture often. Reduce watering sessions in the winter, watering overwintered containers only when the soil feels dry.

Soil

A close-up of a gardener's hands in green gloves planting a young hydrangea bush with small, oval, jagged leaves of a glossy green color into the soil.
Nourish hydrangeas with rich, well-draining, pH-balanced soil.

These shrubs prefer organically rich, well-draining soils with medium moisture—like a humusy woodland floor. They grow in acidic, neutral, and alkaline soils, influencing bloom color except for the white ‘Blushing Bride’ cultivar.

Blue hydrangea blooms need highly acidic soils with a pH of less than 6.0. Add aluminum sulfate or decaying oak leaves to the surrounding soil to increase acidity. Pink blooms occur in slightly acidic to alkaline soils with pH levels above 6.0. To achieve pinker tones, add lime or wood ashes to the soil. A soil test helps determine your soil pH levels and how much you’ll need to adjust them.

Add these amendments in fall or late winter before hydrangeas bloom. A neutral soil yields a purplish-mauve bloom.

For poor soils like clay and sand, generously add composted organic material to the native soil to improve aeration, moisture retention, drainage, and nutrition. Spread a generous three to six-inch layer over the entire planting area.

Temperature and Humidity

The Pink Hydrangea 'Endless Summer' features large, glossy green leaves and abundant, rounded clusters of vibrant pink flowers against a blurred garden background.
Optimize Endless Summer’s growth by mindful winter care practices.

They are deciduous shrubs that tolerate a range of summer and winter temperatures in zones 4-9. While plants are hardy in these zones and don’t require winter protection like other bigleaf varieties, some measures help ensure better flowering and growth in the spring.

To prepare hydrangeas for winter, add a three-inch layer of mulch for insulation. Compost, pine bark, straw, and leaf litter work well. Mound leaf litter or straw to 12 inches high around stems to protect the base of plants and buds on old wood. Remove mounded straw or leaves after the final frost passes in late winter or spring.

Endless SummerⓇ thrives in regions with heat and humidity, provided there is plenty of air circulation, and the soil is moist but not overly wet. Bigleaf hydrangeas may wilt in the afternoon’s heat, even with moist soil, but they’ll revive in cooler evening temperatures.

For container-grown plants, move them to a sheltered location to overwinter. For best success, overwinter pots in a sheltered garage or basement.

Fertilizing

Close-up of a gardener's hand full of blue granular fertilizer over a young hydrangea bush in the garden.
Boost hydrangeas’ beauty with compost and phosphorous-rich fertilizer.

Hydrangeas benefit from compost amendments at planting and each fall or spring. As heavy repeat bloomers, they’ll appreciate a spring fertilizer application. Look for an organic granular slow-release high in phosphorous, like 10-30-10, to promote growth and flowering.

A spring dose is usually enough, but if you notice a decrease in flowering after mid-summer, give plants one more application. Avoid overfertilizing, as too much nitrogen produces leafy growth with less flowering. Stop fertilizing in the fall as plants stop actively growing and prepare for winter dormancy.

Maintenance

Close-up of female hands pruning a faded spherical hydrangea inflorescence with green-pinkish flowers using pruning shears.
Maintain hydrangeas’ natural beauty with selective pruning and care.

These shrubs generally don’t need pruning. If you choose to prune for shaping, do so immediately after plants flower. Prune out any dead, weak, or winter-damaged stems in late winter or early spring. Avoid pruning Endless SummerⓇ in the fall to retain old wood buds.

Enjoy fresh hydrangeas in summer floral arrangements, or preserve them for drying by clipping stems back to a pair of healthy buds. Deadhead spent flowers in late summer to promote continued flowering. Stop deadheading in the fall and allow flowers to remain for continued seasonal interest.

As regular maintenance, keep hydrangeas mulched with a healthy three-inch layer of pine bark, compost, pine needles, or leaves.

Propagation

Close-up of female hands planting young cuttings of Hydrangea macrophylla in black plastic pots indoors.
Propagate hydrangeas easily through stem or leaf cuttings.

Hydrangeas propagate through stem cuttings, leaf cuttings, and layering. However, Endless SummerⓇ hydrangeas are protected by a plant patent that prohibits propagation. Purchase Endless Summer from retail nurseries to add them to your landscape.

Six varieties are available in the collection. Each boasts unique blooms and forms for exciting color in the summer garden. All produce flowers on both old and new wood for a long-lasting display and hardiness against winter damage. In addition to Hydrangea macrophylla ‘Bailmer’ The Original are the following selections:

BloomstruckⓇ

This hydrangea BloomstruckⓇ has dark green, glossy leaves and produces large, round clusters of vibrant blue to purple.
This hydrangea variety captivates with vibrant blooms, resilient foliage, and compact size.

Bloomstruck boasts large mophead blooms in violet blue (acidic soils) and rose pink (alkaline soils) among glossy green foliage with red veins and petioles. Burgundy stems are sturdy and add visual interest.

‘Bloomstruck’ is disease-resistant, particularly to powdery mildew. It features improved heat tolerance. Like ‘The Original’, plants reach three to four feet tall and wide.

Blushing BrideⓇ

Hydrangea macrophylla ‘Blushing Bride’ features glossy green leaves and large, rounded flower clusters that start white and gradually blush to soft pink.
Experience the enchanting transition from white to blush pink blooms.

‘Blushing Bride’ brings pure white double blooms to the Endless Summer collection. As they age, the blooms transition to blush pink. The large flowers are beautiful on the bush and in floral arrangements.

‘Blushing Bride’ is hardy in zones 5-9, making it slightly less winter-hardy than the other selections. Plants grow four to six feet tall and wide. The white blooms of ‘Blushing Bride’ aren’t affected by soil pH levels for coloration.

Pop StarⓇ

Hydrangea macrophylla ‘BAILMACSIX’ has dark green leaves and dense, vibrant blue flower cluster of small, fertile flowers surrounded by larger, showy sterile florets.
Add vibrant hues to compact spaces with Pop Star hydrangeas.

‘Pop Star’ brings bold color to a compact but mighty plant. This bigleaf hydrangea grows only 18-36 inches tall and wide and produces loads of flower clusters in vivid blue or bright pink, depending on soil pH. The rich flower pigments pop against the dark, lush foliage. 

‘Pop Star’ makes a showy, low-growing grouped planting arrangement or container specimen. ‘Pop Star’ is an excellent option for growing bigleaf hydrangeas with continual seasonal color in small space gardens.

Twist-n-ShoutⓇ

Hydrangea macrophylla Twist-n-Shout showcases glossy green leaves and lacecap flowers with pink and blue centers surrounded by lighter outer blooms.
Elevate your garden with profuse blooms and sturdy stems.

‘Twist-n-Shout’ dazzles the garden with lacecap blooms in hues of rosy pinks and periwinkle blues according to soil pH. The plants bloom profusely, and sturdy stems in rich red hold the blooms upright.

Plants grow three to five feet tall by three to four feet wide. These cold hardy growers (zones 4-9) are reliable bloomers and garden performers.

Summer CrushⓇ

Hydrangea macrophylla ‘BAILMACFIVE’ Summer Crush displays rich green leaves and large, mophead clusters of deep pink to raspberry-red flowers.
Inject vibrant hues into your garden with Summer Crush blooms.

‘Summer Crush’ shakes up the series in vibrant raspberry and violet tones with chartreuse buds. Huge blooms cover compact plants, which are the same size as Pop Star, at a tidy 18 to 36 inches tall and wide.  

‘Summer Crush’ adds bright pigment to container planting arrangements or low borders. These are hardy in zones 4-9.

Common Problems

Fortunately, this hydrangea series is free of most pests and resists many common diseases. Occasionally, aphids visit hydrangeas. Fungal diseases like leaf spot and powdery mildew are sometimes problems for hydrangeas. The best prevention is ensuring proper cultural conditions through even watering, partial shade, air circulation, and healthy soils.

Pests

Close-up of a hydrangea stem infested with a swarm of tiny pale green aphids and a few ants.
Combat insects on hydrangeas with early detection and treatment.

The best way to control insects is through early detection. Aphids are common sap-sucking garden insects that feed on a variety of plants. They don’t often cause a severe threat, but they can cause plants stress and leave behind a sticky honeydew that can lead to black, sooty mold. 

If you notice curled leaves, stunted growth, or signs of the insect, spray plants with a stream of water early in the day to knock them off the stems and deter further damage. A simple horticultural soap or Neem oil treats infestations, but improper use will harm beneficial insects. Follow label instructions and spray only when pollinators are not as active.

Deer may nibble or rub on your hydrangeas. You can bolster prevention of deer by planting your hydrangeas with deer-resistant plants. Borders of these should keep deer at bay.

Spider mites may also attack your hydrangeas, sucking plant sap. They are most active in dry, warm seasons. Keep the soil moist to prevent them. Encourage their natural predators with plantings of beneficial host plants. If you see Japanese beetles feeding on leaves, manually remove them.

Diseases

Close-up of hydrangea leaves affected by powdery mildew with a grayish powdery coating on the surface.
Prevent fungal diseases with proper cultural practices and early intervention.

As with pests, the best disease control is prevention through cultural conditions. While this shrub is resistant, common fungal diseases may be an issue with water fluctuations or humid conditions in hot climates.

Cercospora leaf spot commonly affects bigleaf, smooth, panicle, and oakleaf hydrangea types. Rainfall and overhead watering promote the spread of this fungal disease, which is visible by brown dots on leaf surfaces. Cercospora rarely kills an established hydrangea, though heavily impacted plants may show less blooming and vigor.

To prevent the spread of Cercospora, remove fallen leaves from around plants and remove affected leaves from the plant during the growing season. While chemical fungicides offer treatments, they won’t prevent the disease from appearing on new growth.

Powdery mildew is another common fungal disease impacting bigleaf hydrangeas. Powdery mildew appears as a gray-white powdery substance on leaves, stems, and buds. Leaves may distort and drop.

As with Cercospora, remove affected plant parts and any dropped leaves. Horticultural oils like Neem can treat fungal diseases early on (but these impact beneficial insects, so be sure to follow application requirements).

In heavy rain and subsequent hot weather, bacterial wilt can damage hydrangeas. If you notice bud clusters and leaves have contracted blight, or your hydrangea is wilting, this is most likely the case. There is no control but prevention. Do this by pruning away blighted areas of the plant as they arise.

Frequently Asked Questions

Why is my Endless Summer hydrangea not blooming?

They grow best with consistently moist soils in partial shade or dappled light, especially morning sun and afternoon shade, depending on your climate. If your hydrangea isn’t blooming, it may be related to too much sun exposure or water needs—too much or too little. Overfertilizing also leads to a decline in blooming.

When do Endless Summer hydrangeas bloom?

They bloom in spring in warm climates and early summer in cool climates. These repeat-bloomers flower until frost.

Are Endless Summer hydrangeas deer-resistant?

Unfortunately, no hydrangea is free from the browse of a hungry deer. An organic deer repellant applied often and switched occasionally may help deter deer. Planting hydrangeas in containers near active areas or among lesser-favored plants may be worth a try, too.

Final Thoughts

There’s nothing quite like a hydrangea in full bloom to mark the summer season. Endless SummerⓇ, whether The Original or a newer cultivar, is a showstopper that punctuates the warm-season display.

Overflowing with blooms from summer through fall and with an easy-care nature, Endless SummerⓇ is a top hydrangea pick for beginning gardeners and professionals alike. Enjoy the floriferous bounty of these favorite “endless” hydrangeas.

SHARE THIS POST
A woman arranges a bouquet of stunning cut hydrangea flowers in pink and purple hues in a white vase, placed on a white table in the kitchen.

Shrubs

5 Tips for Long-Lasting Cut Hydrangea Blooms

Hydrangeas delight us in the garden and fresh floral arrangements all summer long. Their stunning blooms, in a variety of shapes, sizes, and colors, offer boundless options for elegant and easy-going fresh flower displays. Drying hydrangea blooms makes the beauty last even longer. Join garden expert Katherine Rowe in exchanging simple tips for long-lasting cut hydrangeas.

The PeeGee Hydrangea features sturdy, woody stems, dark green, serrated leaves, and large, conical clusters of white flowers that turn pink as they mature.

Shrubs

How to Plant, Grow, and Care for ‘PeeGee’ Hydrangeas

For a classic, reliable hydrangea with old garden grace, look to the splendid ‘PeeGee’ panicle hydrangea. In cultivation for over 150 years, ‘PeeGee’ hydrangeas grow in a wide range of garden conditions. Here, garden expert Katherine Rowe explores the appeal of growing this old-fashioned, big-blooming hydrangea.

A sunlit Japanese barberry showcases vibrant foliage and clusters of red fruits, basking in the warm glow

Shrubs

21 Showy Shrubs to Plant Instead of Japanese Barberry

Are you searching for some shrubs to fill your landscape? You may be tempted to grow Japanese barberry because it is familiar and widely used commercially, but know that there are many showy and better-behaved alternatives to this invasive species. In this article, gardening expert Liessa Bowen offers 21 fantastic alternatives to growing Japanese barberry in your landscape.

A red-flowering currant, its vibrant leaves embracing clusters of delicate pink blooms, basks in the warm embrace of the radiant sun.

Shrubs

17 Best North American Native Shrubs For Your Garden

Do you want to diversify your landscape? By adding a few beautiful native shrubs, you can easily increase its structural diversity, color, and curb appeal. In this article, gardening expert Liessa Bowen introduces 17 of her favorite easy-to-grow and super-showy native shrubs.

A shrub adorned with clusters of crimson berries and lush green leaves, creating a rich tapestry of color and texture in the garden landscape.

Shrubs

16 Pretty Garden Shrubs with Red Berries

Perennial shrubs add a layer to your landscaping, creating a beautiful backdrop for other flowering plants. Shrubs also create a hedge row, windbreak, or create a boundary at a property line. But what makes these shrubs stand out from the endless varieties to choose from? Well, the contrast between red berries and green foliage makes them even more visually appealing. Gardening expert Kelli Klein provides a list of 17 garden shrubs with red berries.