Preserving a Masterpiece: The Next Generation of the Conservatory Garden's Crabapple Allées

Central Park’s only formal garden has long remained a favorite spot and must-see destination for New Yorkers and visitors from around the world alike. The Conservatory Garden offers an abundance of floral displays and other highlights: the colorful greeting of tulips each spring, the babble of its striking fountains, the smell of lilacs, its intimate rows of crabapple allées. Meanwhile, hidden details like lighting, pavement, sanitation, drainage, or tree health aren’t what visitors notice about the space.

THE HIDDEN ESSENTIALS OF AN URBAN OASIS

Over 85 years after the Garden first opened in 1937, the Central Park Conservancy is currently restoring these vital components to protect this space for many generations to come. The project includes the replacement of one its most prominent features: magnificent allées of 44 flowering crabapple trees in the Italianate Center Garden. After decades of enjoyment and constant care, they are deteriorating and reaching the end of their sustainable lives.

Given the overall health of the allées, the Conservancy made the decision to replace all the remaining crabapple trees at the same time. The comprehensive replacement will also maintain the consistency and beauty of the allées’ unique architecture and design. We first noticed the onset of the crabapples’ decline many years ago, and our team of landscape architects, horticulturalists, arborists, and other experts have been planning for their replacement ever since.

This is not the first time the Garden’s crabapples have been replaced in their entirety. Through extensive historical research, the Conservancy’s team determined that the existing trees mark the second full planting of the allées in the Garden’s 85-year history. They were planted in the mid-1950s to replace the original trees from 1937, making the incoming batch its third planting. “The Conservancy is looking at both the Garden and its allées holistically with their longevity at the center of our work. People see what’s on the surface. But every project we do has important invisible pieces to them: irrigation, path accessibility, planting health. All of these elements are vital to visitors’ experience of the Garden. They are what make things work,” explains Bob Rumsey, Landscape Architect Studio Director at the Conservancy.

The Conservancy’s current effort is the most comprehensive restoration of the Conservatory Garden to-date, a multi-phased plan that began in early 2022.

“Prior to our current restoration project, much of the infrastructure that exists in the Conservatory Garden today is from the original garden construction—but everything has a lifespan,” says Bob. He oversees a team of eight landscape architects, has been a landscape architect himself for 30 years, and has worked for the Conservancy for a decade. “The Garden’s infrastructure is outdated and, in some cases, failing—especially the drainage, which has significantly deteriorated to the point where a lot of the pipes are broken or collapsed.”

THE CRABAPPLE’S FINITE LIFECYCLE

As the Conservancy began planning for the restoration of the Conservatory Garden, the replacement of its crabapple centerpiece demanded years of careful arboricultural and historical research, sourcing, cultivation, and selection. Not only are the allées one of the most spectacular sites in Central Park—both in and out of bloom—the specific planting from which they are composed presents unique challenges and considerations.

Flowering crabapples have a much shorter lifespan than many other tree varieties, especially compared to most of the large canopy trees found throughout Central Park. Typically, crabapples only live between 40 and 60 years, depending on their species, where they are planted, and the quality of their care.

“It’s very, very rare for crabapples to extend into that 80- or 100-year life expectancy that we associate with trees, which is what the existing trees are approaching,” explains arborist Paul Cowie of the urban forestry consulting firm Paul Cowie and Associates. Paul worked closely with the Conservancy on this project, and his previous work includes consultation for the National 9/11 Memorial, the Constitution Gardens, and Ellis Island. A large gap in Park records during the mid-20th century, along with challenges to determining the age of trees with multi-stemmed trunks, made it difficult for the Conservancy to know the exact age of the existing trees. However, through extensive research of other records and arboricultural tree-core analysis, our team determined that they were planted in the mid-1950s, placing them past their expected lifespan.

While it’s natural to become attached to the beloved trees that are part of our daily lives, communities, and special memories, Paul says it’s important for people to understand that no tree lives forever. “When a tree dies, it’s not like an animal where it’s alive, its heart stops, and then it’s no longer alive. It’s more of a process—a progressive deterioration in the health of the tree. There might be something that triggered it, and then other stressors often pile on the declining tree and portions of it will die. We call that ‘die back:’ the progressive loss of tree parts and loss of physiological function. That’s the phase the existing trees are in now,” Paul says.

In addition to having relatively short lifespans, crabapples are especially prone to various diseases. While the lists of ailments that can plague this genus is long, among the most common and persistent concerns are two varieties of fungal infections: ordinarily referred to as “apple scab” and “cedar apple rust.” If you look closely at the Garden’s current trees, you may notice spotting on their leaves, a symptom of the scab and rust infections that cause leaves to yellow and drop every summer.

Our arborists and experts can spot certain indicators of structural deterioration such as branches that may fall or require removal. The Conservancy has closely monitored the structural integrity of these crabapples for many years, tending to them with extensive pruning and special treatments to extend their longevity as much as possible.

“There are not many organizations that care for trees at the level that the Central Park Conservancy does,” Paul shares.

Despite this special care, the Conservancy has already had to remove a half dozen of the trees that make up the current allées due to the progression of similar disease, decay, and damage that we see in many of the remaining trees. The accumulation of wood decay is a serious safety concern for trees in urban environments like Central Park.

ENHANCING RESILIENCE THROUGH MODERN CULTIVARS

The Conservancy’s team of experts prioritized resilience when considering new varieties of crabapples to replace the current ones. Modern varieties can offer better protection from the same diseases that have caused damage to the Garden’s current trees.

“It wouldn’t have been responsible or wise for the Conservancy to put the same type of tree back into the Garden knowing that they’re not very resistant to disease. So, we began looking for today’s contemporary cultivars that could provide disease resistance, while still possessing the same kind of aesthetic attributes that are characteristic of and essential to the Conservatory Garden allées,” Bob shares.

While the Garden’s new crabapple trees are better equipped to fend off potential threats, they can still be prone to infection under the right conditions and will require ongoing care, monitoring, and treatments from the Conservancy as they grow and age following planting.

UNDERSTANDING THE GARDEN’S ORIGINAL DESIGN INTENT

Though the Conservancy opted for a new species of crabapple, it was paramount for our team to understand the qualities of the current trees—as well as the botanical, design, and planting history of crabapples in the Conservatory Garden—to inform the tree selection.

Taking the Conservatory Garden’s distinct aesthetic requirements and the historical precedent of these previous plantings into consideration, Conservancy experts determined a list of desirable qualities for the new variety of crabapple and set out in search of a tree could fit this extensive bill. Their goal was to find one whose blossoms were congruent with the historical seasonal attributes of the Garden. The new trees needed to have green leaves (which in crabapples, can be various shades of green, red, or a combination of the two) and pink or white blossoms. Perhaps above all, their form and branching structure had to maintain the magnificent and everlasting sculptural quality that make the Conservatory Garden allées so special.

“How complicated can you make tree planting?” Paul jokes. “I actually took photos of the existing trees and drew lines to measure the angle of their branches. A cool quality of those trees is that there is angle variation among their branches, but it is all within a certain range. We wanted to know that we could recreate that same form to the extent that the new tree stems are all at similar angles.”

THE SEARCH FOR THE NEW CRABAPPLE TREES

Our experts considered an extensive list of crabapple cultivars—of which there are around 900—and ultimately found an ideal selection in Malus x. zumi var. calocarpa, or the redbud crabapple. Its fragrant blossoms begin as reddish-pink buds in the spring, unfurl into soft pink petals, and gradually fade into a white hue. The redbud crabapple displays a higher resistance to disease than the previous batch of trees. It possesses a dense form, with a multi-stemmed trunk and upright arching branches—consistent with the crabapples that have presided along the allées throughout the Garden’s history.

The Conservancy found and selected 70 of the redbud crabapples, dug them from the ground, and have been growing them at the renowned Halka nurseries in New Jersey since 2019. In hopes of minimizing the damage that can occur when they are transported to and planted in the Garden, our experts utilized a novel approach: a technology called “air pots.” In the years since the trees were selected, the Conservancy’s team, along with Paul, has pruned the trees annually to help shape their branching structure to further match that of the existing trees.

In the months leading up to their planting, the Conservancy’s landscape architects also vetted each of the 70 trees, and carefully selected 44 with the most appropriate form and fullness for the Conservatory Garden. Acting as curators, they also painstakingly selected the facing of each individual tree, considering how visitors would view each specimen from the angle at which they passed. While visitors to the Garden are seldom aware of this hidden work or meticulous attention to detail, these decisions come together to create a special feeling for the many who will walk the path of the allées in the coming decades—the opportunity for a magical experience in each visit.

At the time of planting, the trees will be approximately one decade old, with plenty of growing to look forward to as they progress toward their mature height and form. Patient visitors will notice new phases of tree growth over the years. “You don’t actually see trees grow, right? But if you were to, say, snap a photograph from the same spot every year, I think it would be impressive how quickly you’ll notice them maturing,” Paul says.

Thanks to the expertise and ongoing work of our dedicated staff, the iconic and historic Conservatory Garden—and the crabapple allées—will remain healthy, beautiful, and in optimal working order, now and for many years into the future. “We’re stewards of the landmark and stewards of Central Park, and we know how vital this space is to the public and to New York. Throughout this restoration, we’ve taken the utmost care to consider how people perceive, experience, and enjoy the Garden,” Bob says. “We can all see these trees grow up and mature together, and that was the intent of the original landscape architect.”

Amileah Sutliff is the Senior Marketing Writer & Editor at the Central Park Conservancy.