Replacements for the Ash Tree

Andrew Bunting

The Emerald Ash Borer (EAB) has devastated all species of Fraxinus throughout the eastern half of the United States. All 16 native species of native ashes—including green ash (Fraxinus pennsylvanica), white ash (Fraxinus americana), black ash (Fraxinus nigra), blue ash (Fraxinus quadrangulata) and others—have been decimated. There’s ongoing research to find controls for EAB, but the destruction of the native forests and plantings in residential areas continues.

Pictured far left: American Dream oak tree • left: Redpointe maple tree

Most of the species of Fraxinus are tall and upright trees. They have compound leaves with many leaflets that create a filtered canopy compared to some oaks and maples, which can have a very dense canopy. Like many native trees, they’re important for supporting birds and insects. Depending on the species, they can have orange, yellow or purple fall color. Over the years there have been many selections of both Fraxinus pennsylvanica and Fraxinus americana for shade trees and street trees. With all ashes being impacted by EAB, it’s important to start considering alternative species that will fill the void in the landscape created by the disappearance of ashes.

There are several native oaks to consider as replacements for Fraxinus. The willow oak, Quercus phellos, has a thin willow-like leaf. This oak tree is pyramidal when it’s young and will broaden over time. Amongst the native oaks, it’s one of the fastest growing. At maturity, it’ll reach up to 75-ft. tall with a spread of 50 ft. It’s hardy to USDA Zones 6 to 9 with yellow to yellow-brown fall color. It has great urban tolerance and has been used successfully in myriad city plantings.

Equally durable in the urban environment is the swamp white oak (Quercus bicolor). As the common name implies, it’s one of the few oaks tolerant of moist soils,  but also thrives as a street tree, or a canopy or lawn tree. The leaves are broad and lobed and turn yellow in the fall. This pyramidal tree will broaden over time and very mature specimens can reach over 80-ft. tall. American Dream is a selection that’s shown great resistance to powdery mildew and Anthracnose, and Beacon is very upright, reaching 40-ft. tall with a much narrower spread. The swamp white oak is hardy to USDA Zone 4.

Adapted to the high pH or calcareous soils of the Midwest is the shingle oak, Quercus imbricaria. The leaves are similar to the willow oak, but a little broader, therefore providing a slightly denser shade. In the summer, the leaves are a dark glossy green and turn yellow to red in the fall. The canopy is upright and oval, and at maturity Quercus imbricaria can reach 50-ft. tall.

Many of the red maples, Acer rubrum have a similar stature to the ashes. In the wild, depending on the species, ashes can tolerate lowland wet conditions, as well as upland dryer conditions, and the same can be said for the red maples.

The red maples serve multiple niches in the landscape from growing in natural plantings to being one of the top landscape and street trees. Dozens of selections of red maples have been made. It’s called the red maple due to the fire engine-red fall color. While it can thrive in tough, dry, urban conditions, it’ll also thrive in wet, poorly drained soils or in areas where there are inundation events and flooding.

Acer rubrum Redpointe is a 2025 Gold Medal Plant winner from the Pennsylvania Horticultural Society. Redpointe has smaller leaves than the typical red maple, which creates a finer canopy. It has a strong central leader with a broad canopy and will reach 45- to 50-ft. tall at maturity and is hardy to USDA Zone 5.

October Glory is used in areas where there might be excessive heat. The canopy is more rounded than Redpointe. Red Sunset is one of the most widely used of the red maple selections. It’s vigorous and upright, and hardy to Zone 4. For extreme hardiness, Acer x freemanii Autumn Blaze is a great choice. This hybrid between Acer rubrum and the silver maple Acer saccharinum is hardy to USDA Zone 3 and is a great choice for central and more western parts of the U. S.  This tree is also a Pennsylvania Horticultural Society Gold Medal Plant recipient.

One of the most versatile of the native trees are the sour gums or tupelos (Nyssa sylvatica). It’s native from Massachusetts to Florida, and west to east in Texas, Arkansas and Missouri. It exhibits great tolerance for myriad soil types, including moist and poorly drained soils. In its youth, it’ll be a pyramidal tree and then become more upright, often with architectural twisting branches. Noted for its fall color, it’s often one of the first trees to exhibit fall color with yellows to vibrant red. It sets tiny purple-black fleshy fruits, which are an important seed source for many native songbirds. Wildfire is fast growing and the newly emerging leaves have a flush of red. Red Rage has vibrant red fall color and Green Gable has a more upright habit.

Gymnocladus dioicus, the Kentucky coffee tree, has compound leaves with many leaflets. When it’s young, it has a gawky stature, but as it matures it fills out and becomes an upright tree not that dissimilar to the ashes. It has a broad range reaching up into New York and can be found as far west as Nebraska. It’s in the legume family and does produce large broad pods that can be messy, therefore plant a male clone, such as Espresso or Skinny Latte from the Chicagoland Grows program. The Kentucky coffee tree has become one of the most popular street trees because of its durability. The fall color is yellow and it’s hardy to USDA Zone 4.

There are many great native trees to consider as substitutes for the ash tree. While they may not be exactly comparable, the options covered here do offer many of the ornamental attributes ashes are beloved for, along with important ecological functions. GP

Pictured: 3. Red Rage tupelo tree 4. Wildfire tupelo tree 5. Espresso Kentucky coffee tree

Andrew Bunting is the Vice President of Horticulture for the Pennsylvania Horticultural Society (PHS), which uses horticulture to advance the health and well-being of the Greater Philadelphia region. To learn more about PHS, or to become a member and support greening initiatives in over 250 neighborhoods, visit PHSonline.org.