Common Name: American Elm

General Information

Ulmus americana is a deciduous tree with a spreading, commonly vase-shaped crown; it usually grows 18 - 25 metres tal, occasionally reaching 35 metres[, ]. In woodland conditions on good soils the bole can be 120 - 150cm in diameter and free of branches for 15 metres or more[].
The tree has a wide range of traditional uses as a food, medicine and source of materials. The wood is commonly harvested from the wild and traded internationally. Prior to the onset of Dutch Elm Disease, the tree was commonly planted as a street and shade tree of choice because of its fast growth and pleasant shape and size[].
The plant is occasionally cultivated outside its native distribution, and it has escaped sporadically from cultivation[].

Known Hazards

None known

Botanical References

, ,

Range

Eastern N. America - Saskatchewan to Nova Scotia, south to Texas and northern Florida

Habitat

Rich soils, especially by streams and in lowlands[, ]. Alluvial woods, swamp forests, deciduous woodlands, fencerows, pastures, old fields, waste areas; at elevations up to 1,400 metres[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	21.00 m
Growth Rate	Medium
Pollinators	Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

Within the natural range of Ulmus americana, the climate varies from warm and humid in the southeast to cold and dry in the northwest. Winter temperatures can fall as low as -18°c (with extremes down to -40°c) in the north of its range, whilst in the far south even mild frosts are very rare. Summer temperatures can vary from 16 - 27°c, with extremes to 40°c[]. The average frost-free period can range from 80 to 320 days. Mean annual precipitation can be as low as 380min, or as high as 1,520mm, with a preferred range of 760 - 1,270mm, with most of it occurring during the growing season[].
Prefers a position in full sun, but tolerates light shade[, ]. Grows best in a moist, fertile, well-drained loamy soil, but can adapt to most soils and drier sites[]. Plants are tolerant of urban pollution[]. Plants are found in the wild on a range of soil types, ranging from acidic to mildly alkaline[]. Prefers a pH in the range 5.5 - 8[].
Trees are moderately fast-growing and live for at least 300 years in the wild[, ].
Seed production usually starts when a tree is around 15 years old from seed, though rarely becomes abundant before the tree is around 40 years old[].
When cut down, mature trees usually produce vigorous stump and root sprouts - trees killed by Dutch Elm Disease also resprout from the roots and these new growths can persist for 20 years or more before becoming large enough to be attacked by the disease again[].
This species is particularly susceptible to 'Dutch elm disease'[], a disease that has destroyed the greater part of all the native elm trees growing in countries such as Britain and USA. The disease is spread by means of beetles. Mature trees killed back by the disease will often regrow from suckers, but these too will succumb when they get larger. There is no effective cure (1992) for the problem, but most E. Asian, though not Himalayan, species are resistant (though not immune) to the disease so the potential exists to use these resistant species to develop new resistant hybrids with the native species[].
Some cultivars, such as 'Valley Forge', 'Jefferson' and 'Princeton' have been developed that show moderate to strong resistance to Dutch Elm Disease[].
The various species of this genus hybridize freely with each other and pollen is easily saved, so even those species with different flowering times can be hybridized[].

Edible Uses

Leaves - raw or cooked. We have no specific information for this species, but the very young leaves of all Ulmus species can be eaten, and generally have a mild flavour[].

The red inner bark has been used to make a coffee-like drink[].

Medicinal

An infusion made from the bark has been used in the treatment of bleeding from the lungs, ruptures, coughs, colds, influenza, dysentery, eye infections, cramps and diarrhoea[, ]. An infusion of the bark has been taken by pregnant women to secure stability of children[].
Applied externally, a decoction of the bark has been used as a wash on wounds[].

A decoction of the inner bark has been taken in the treatment of severe coughs, colds, menstrual cramps[]. An infusion of the inner bark has been drunk, and used as a bath, in the treatment of appendicitis[]. The inner bark has been used as an emollient on tumours[].

An infusion of the root bark has been used in the treatment of coughs, colds and excessive menstruation[]. A decoction has been used as an eye wash in the treatment of sore eyes[].

Agroforestry Uses:

The tree is a prominent early invader of abandoned fields and makes a very good pioneer species for restoring woodland[]. However, due to its susceptibility to Dutch Elm Disease, it is probably not suited to this purpose at the present time[].
The leaf litter decomposes more rapidly than that of many other trees, usua;lly crumbling readily afterabout 18 months on the ground. They have a relatively high content of potassium and also of calcium (1 - 2%). Because its litter decomposes rapidly and contains many desirable nutrients, the tree is considered a "soil-improving" species[].

Other Uses

A fibre obtained from the stems is used in making paper[]. The stems are harvested in spring, the leaves are removed and the stems steamed until the fibres can be stripped. The outer bark is removed from the inner bark by scraping or peeling. The fibres are cooked for 2 hours with lye and then beaten with mallets. The paper is beige in colour[].

The inner bark is very fibrous and is used in making string and strong ropes[, ].

The bark has been used to make various containers, including those used for gathering maple syrup[].

The wood is hard, strong, moderately heavy, durable. It has a coarse, interlocked grain which means it bends well and also makes it difficult to split. It shrinks moderately, though it also tends to warp and twist. The wood is very durable in water. It is harvested commercially and is used for a variety of purposes including flooring, wheel hubs, cooperage, agricultural implements, mining timbers and many other items[, , , , , , , ]. It is a favoured wood for making hockey sticks[]. Some elm wood goes into veneer for making boxes, crates, and baskets, and a small quantity is used for pulp and paper manufacture[].
The wood is used for fuel[].

Propagation

Seed - if sown in a cold frame as soon as it is ripe, it usually germinates within a few days[]. Stored seed does not germinate so well and should be sown in early spring[]. The seed can also be harvested 'green' (when it has fully developed but before it dries on the tree) and sown immediately in a cold frame. It should germinate very quickly and will produce a larger plant by the end of the growing season[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Plants should not be allowed to grow for more than two years in a nursery bed since they form a tap root and will then move badly.
Layering of suckers or coppiced shoots[].