Manchurian Ash

There are times when we want TOUGH. That’s when we turn to trees like the Manchurian Ash. This tree is hardy even in zone 2, and its shapely, rounded crown, bright green foliage and golden fall colors make it the perfect shade or screening tree where toughness counts for a lot. Cold-resistant for sure, it’s ideal for the prairies and the Midwest, as well as in the harshest urban locations, where most other trees simply won’t make it. It grows well in wet and swampy ground too, such as along ditches and creeks. It seems to also have some resistance to the dreaded emerald ash borer, which is decimating ash trees everywhere. If you want a tough tree that is also attractive, and a tree that is almost guaranteed to grow anywhere, then here it is.

Growing the Manchurian Ash

Size and Appearance

The Manchurian Ash is an upright shade tree, with a single straight trunk and a rounded, tear-drop shaped crown when young, becoming more spreading at maturity. It will reach about 50 feet in height and up to 30 feet in spread, although trees of 100 feet have been recorded in old age, under ideal conditions. The bark is gray, with a fine network of light gray lines, running vertically, over a dark gray background. The winter buds are large and black. The leaves are up to 15 inches long, but divided into 7 to 13 – usually 9 or 11 – leaflets, with one at the tip and the rest in pairs along a short stem. Each leaflet is mid green, and lighter green on the lower side, up to 4½ inches long and 2 inches wide, oval, with a toothed edge. The leaf is slightly rough to the touch because of scattered bristles on its surface, especially along the veins. One of the first trees to color in fall, the leaves turn attractive shades of golden yellow, sometimes with red highlights.

Before the leaves appear in spring, clusters of inconspicuous greenish-yellow flowers may be seen. These can become clusters of 2-inch long seeds, like a maple key, but with just one ‘wing’. A tree with a crop of seeds looks attractive after the leaves fall, although seed production is not definite, and depends on spring weather conditions.

Using the Manchurian Ash in Your Garden

The Manchurian Ash is a great choice for cold regions, where it thrives. In areas with milder winters it may leaf-out early and be damaged by spring frost, but in cold regions, where tree choices are more limited, and for difficult soil conditions, it is a premium selection really worth planting. It is an interesting selection for a collection of trees on a large property. Grow it as a lawn specimen, as a boundary marker or screen, or in open areas on rough or wet ground. It grows well in low-lying spots and beside water, as well as in difficult urban soils and polluted environments.

Hardiness

The Manchurian Ash is hardy in warmer parts of zone 2, and through all the cool zones including zone 6. In zone 7 it may suffer if your summers are very hot and winter not very long. It grows best in interior parts of the country, where the climate is of the continental type.

Sun Exposure and Soil Conditions

Full sun is best for the Manchurian Ash, although it will tolerate a little shade when young, if it rises into the sun as it grows. It grows well in all moist soils, including poor soils, swampy ground, and all but the heaviest clays and driest sands. Once established it will tolerate ordinary summer drought without difficulty, and will grow under ordinary to poor garden conditions.

Maintenance and Pruning

Although not deeply researched, there is evidence to suggest that this ash is much less susceptible to attack by the emerald ash borer (they both come from Asia). This pest is making growing ash trees very difficult, so the Manchurian Ash is a good tree to try. Although susceptible to some other pests and diseases, these are rarely serious and don’t normally prevent normal development. Some removal of over-crowded branches in the crown as it develops can be useful to create a sturdy tree, but it is often not necessary.

History and Origin of the Manchurian Ash

The Manchurian Ash, Fraxinus mandshurica, is native to northern Japan, Korea, and in north-eastern China and Russia, in the area once called ‘Manchuria’. It grows in wet valleys and on slopes among other trees. It was introduced into England in 1882 from St. Petersburg, Russia, but probably arrived in America separately, directly from Japan or China. Botanically it is close to the European ash, Fraxinus nigra, and if it does prove to be reliably resistant to emerald ash borer, it could be a good replacement for that badly threatened tree.

Buying the Manchurian Ash at the Tree Center

If you live in our most northern areas, in the interior of the country, and need a tough tree, the Manchurian Ash is a great choice. We are glad to be able to offer this tree to these clients, knowing how difficult it can be to find suitable tough plants for those areas. If you are interested in testing it for emerald ash borer, in a milder northern area, we encourage that too. But order now, as supplies of ash trees are dwindling, and we don’t know when we will see these trees again.