Bloom Period and Seasonal Color
Grown mostly for it’s unique vase shape
Mature Height x Spread
60 to 90 feet x 30 x 70 feet
The American elm was the quintessential, deciduous street tree throughout many towns and cities in New England until the Dutch elm disease wiped out many of the trees in the early 1900s. You can see why this was such a prized tree. The large trunk grows up to 90 feet tall and has a huge, vase-shaped top making it perfect to provide shade, but also not so much of a space hog on the ground level. Through breeding and selection, there are now American elms on the market with improved resistance to the disease, so this tree is starting to be seen again in landscapes. Because of its size, make sure you have a large enough space to accommodate this beautiful tree in your yard.
When, Where and How to Plant
American elms are hardy to zone 3 and are found throughout New England. Purchase disease-resistant trees from a local garden center or nursery. Plant in spring to early fall in a full sun location. Elms in the wild grow well near streams and wetlands, so make sure the soil is consistently moist. The tree also is tolerant of salty soils.
Keep young trees well watered and mulched with bark mulch to maintain soil moisture conditions and reduce competition from lawn grass and weeds. Fertilize in spring with a layer of compost and an organic plant food sprinkled around the drip line.
Regional Advice and Care
Even though they’re medium-fast growers, it will take many years to grow a sizable elm tree in your yard. Keep the tree healthy by removing dead, diseased or broken branches in fall, keeping it well watered, and fed regularly. Protect young trees from elm beetles and deer browsing.
Companion Planting and Design
You can plant American elms in lawn areas, abandoned meadows or as street trees. They make good shade trees. Elms are striking in the landscape, so plant where you can enjoy the full view of the tree’s structure. Keep a large mulch ring around the tree to reduce grass competition and damage from lawn mowers and string trimmers.
Since Dutch elm disease is still present in the environment, it’s important to choose newer varieties that are reportedly more resistant to the disease. One of the best is ‘Valley Forge’. It has the classic, tall, vase-shape with green leaves that turn yellow in autumn. ‘Princeton’ grows only 70 feet tall, and has also shown good resistance to the disease. ‘Jefferson’ is a hybrid that grows 50 feet tall and wide with good arching branches. ‘Liberty’ is a widely touted variety, but its disease resistance isn’t as good as others and it’s also susceptible to other diseases beyond Dutch elm disease. The Chinese elm (U. parvifolia) is a smaller tree than the American types, but is resistant to this disease and is often used to create disease resistant hybrids.
Excerpted from the New England Getting Started Garden Guide.