Maple trees are known for their fall colors, and the Amur maple certainly lives up to this reputation. With a variety of names like "Flame" and "Embers," this small tree (or large shrub) will set your yard ablaze in autumn with its red or orange leaves. These two varieties, along with "Red Wing," also have red samaras or seeds with wings often called wingnuts or whirlybirds. The green leaves are 1 1/2 to four inches long. They feature three lobes with the side lobes being shorter than the middle lobe. Fall colors will be green, red, or orange depending on the variety. In April and May, panicles of small fragrant white flowers are produced.
Planted in yards for their burst of color, they are also useful for controlling soil erosion and windbreaks. Windbreaks can help during harsh winter conditions by absorbing some of the impacts of winter storms and reducing home heating costs during winter months.
- Botanical Name: Acer ginnala or Acer tataricum subsp. ginnala
- Common Name: Amur maple or Siberian maple
- Plant Type: Deciduous tree or tall shrub
- Mature Size: Grows about 30 feet tall with a trunk about 8 to 16 inches in diameter
- Sun Exposure: Can grow in full sun to shady conditions
- Soil Type: Clay, loam, sand, well-drained
- Soil pH: Acidic or neutral
- Bloom Time: Spring
- Flower Color: White
- Hardiness Zones: 3 through 8
- Native Area: Northeast Asia
How to Grow Amur Maple Trees
The Amur maple works well in the urban garden. It is on the smaller side so that it can fit in most residential landscapes. This tree can handle some shade, salt, and drought.
If your chosen spot has full sun or part shade, it will provide the best type of sunlight for your new tree. Better fall colors will come from trees in full sun.
The Amur maple tree can tolerate a wide variety of soils, poor soil fertility, and is pH adaptable. It might be best to choose a site with an acidic or neutral pH. If the soil is too alkaline, it can cause the tree to develop iron chlorosis. Make the soil more acidic as needed.
The tree also prefers to have moist soil that drains well. It is moderately drought tolerant.
Temperature and Humidity
The Amur maple grows best in U.S. Department of Agriculture plant hardiness zones 3 through 8, which means it can tolerate low temperatures and ice and snow. It prefers cold to hot and grows best where summer temperatures are not high and where humidity is low. If it has too much moisture, it can develop leaf spots or is more prone to disease.
Fertilizer is generally unnecessary for Amur maple trees growing on lawns and in gardens—particularly if those areas receive regular feedings. However, you might want to give fertilizer to a newly planted Amur maple. Use about one cup of a well-balanced 10-10-10 granular fertilizer around the base of a newly planted Amur maple in the early spring after fall planting, or six to eight weeks after spring planting, to encourage rapid growth. Apply the same amount in early summer and again in early fall in the tree's first year, watering it in well after each application. The trees commonly grow 12 to 24 inches a year until they reach their mature height.
Propagating Amur Maple Trees
New trees can be propagated by seeds that have been soaked in water for a day and stratified for a few months. They can also be grown from cuttings, which is necessary to preserve the characteristics of varieties since seeds may not be true to type.
Stem cuttings of young shoots should be done in June or July. The cuttings should consist of two to three pairs of leaves and one pair of buds on the base. Trim the cuttings below the lowest node to remove the lower leaves leaving three or four at the tip. A rooting hormone may be applied to improve rooting before planting. Insert the cuttings in the rooting medium up to half their length; the leaves should not touch. The cuttings should root in two to three weeks, and then can be potted.
Prune and train the tree in winter to have a single trunk if desired by choosing a central leader. If you leave it as a multi-trunked shrub, it can be pruned and trained for use as a hedge. The Amur maple tree has the potential to be invasive depending on the area.
Common Pests and Diseases
This maple species is sometimes prone to a few pests and diseases. If you notice holes in your trunk that are lined up, you might have a yellow-bellied sapsucker (Sphyrapicus varius) in the neighborhood. You can use woodpecker deterrent methods to help keep your trunk healthier. Other pests include:
- Two-spotted spider mite (Tetranychus urticae)
Diseases like giant tar spot (Rhytisma acerinum) and leaf spots are possible but are not serious problems for the Amur maple. More serious potential diseases include:
- Anthracnose: This fungus can cause defoliation if severe. It can be avoided by destroying the diseased parts of the plant early, or by applying fungicides or by controlling the insects that spread the fungus to other plants or different parts of the same plant.
- Crown gall (Agrobacterium tumefaciens): A bacterial disease, it causes round, wart-like growths—two inches or larger in diameter—to appear at or just above the soil line, or on lower branches and stems. Plants with several galls may become weakened, stunted and unproductive. Young plants can be killed by developing gall tissue. Sometimes existing galls can be removed with a sharp pruning knife but unless the bacteria is eliminated from the soil, it can spread to other plants. So it may be best to remove and destroy the diseased plant.
- Phytophthora cankers and rots (Phytophthora spp.): Diseases are caused by the Phytophthora fungus which lives in the soil. Symptoms include early fall color or pale green leaves, reduced size of leaves and shoots, and bleeding of a reddish-brown colored liquid from the stems. Remove infected branches as soon as possible to control spreading.
- Verticillium wilt (Verticillium spp.): This disease causes the branches of the tree to wilt or die. Very rarely the infected sapwood will be stained dark or olive green in color. If the infection is severe, the tree cannot be saved, however, if the infection is in the early stages, pruning the infected branches and fertilizing the tree can help to save it.
- Iron chlorosis: Plants grown in alkaline soils or poor-draining soils can develop his iron deficiency. Treatment is not easy and can be expensive, but it is possible to replace lost iron through soil applications, foliar spraying, and trunk injections.