Amur Maple (Acer ginnala): Facts, Uses, Pests and Diseases
The Amur maples being an invasive species, are tolerant to pests and most diseases. However they are sometimes prone to these pests and diseases, and have to be looked after, which one can definitely do. We will look into details of the different pests that can affect the Amur maple, the different diseases that they are prone to and the actions that need to be taken to prevent the plant from dying. In addition to these, we will also be looking into the various uses of the Amur maple, the different cultivars, some interesting facts and also different styles (mainly bonsai) in which these maples can be grown.
If you wish to read in detail about how to grow the Amur maple (acer ginnala), please follow the link below. It has detailed steps that are involved in growing the Amur maple.
Before getting into the details, I have listed the explanation of a few terms that are used in this hub.
Explanation of terms used:
Deciduous – plants shedding foliage at the end of the growing season
Iron chlorosis – Iron deficiency
Cultivars – a variety of plant developed from a natural species
Stump – base part of a tree
Samaras – winged one seeded indehiscent fruit
Indehiscent - doesn’t open spontaneously at maturity to release seeds
Acidic - having an excess of hydrogen atoms (having a pH of less than 7)
Alkaline soil - clay soils with high pH, poor soil structure and a low infiltration capacity
Xeriscaping - landscaping designed for dry conditions to conserve water
Astringent - a drug that causes contraction of body tissues and canals
Herbicides - a chemical agent that destroys plants or inhibits their growth
Pests and other problems that affect the Amur Maple (Acer ginnala):
- Mostly Amur Maples are free from pests. They are sometimes damaged by the Yellow bellied sap-sucker (Sphyrapicus varius) and this can be confirmed if there are holes on the tree trunk.
- Other pests that affect the Amur maple are aphids that can cause leaf drop. Other symptoms of aphid infestation can be honey dew underneath the leaf or on objects beneath the tree. Aphids can be brought under control by spraying, but other predatory insects usually bring the population of the aphids under control.
- Another pest on the Amur maple are the scales like horse chestnut scales . The most common scales are the cottony maple scale that form cottony masses on the lower sides of branches. These can be controlled or eliminated by spraying with horticultural sprays during the early spring season to prevent them from growing.
- Borers are another pest that indicate that the tree is not healthy. These pests are difficult to control. The type of borer infecting the tree has to be identified and proper insecticides for that particular borer has to be sprayed at a very early stage.
- Twospotted spider mites (Tetranychus urticae) are another type of pests that affect the Amur maple.
- Amur maple are also sensitive to phenoxy herbicides
Diseases that the Amur Maple (Acer ginnala) can be prone to:
- They are prone to bacterial diseases like Crown gall (Agrobacterium tumefaciens) and also prone to fungal diseases like Anthracnose, Phytophthora Canker, Basal Rot, & Root Rot, Verticillium Wilt, giant tar spot (Rhytisma acerinum), leaf spots, iron chlorosis and Wood Rots and Decays.
- Maple Anthracnose is caused by a certain type of fungi (for example K. apocrypta). This disease causes sunken spots or scorch during late spring or early summer and severe infection may lead to defoliation. This can be serious during rainy seasons and sometimes masses of fungus can be found on the lower surface of the leaves. This can be avoided by destroying the diseased parts of the plant at an early stage of infection or by applying fungicides or by controlling the insects that spread the fungus to other plants or different parts of the same plant.
- Phytophthora Canker is caused by Phytophthora, which is a fungus that causes bleeding canker in maple and many other trees. They disrupt the water transport within the plant. The symptoms of this infection are early fall colour or pale green leaves, reduced size of leaves and shoots and bleeding of a reddish-brown coloured liquid from the stems. The Phytophthora fungus lives in the soil. This can be controlled at an early stage by removing infected branches. Diseased large branches and trunks maybe scraped to remove the outer bark to reveal the infection and exposure to dry conditions can cause the infection to dry out. Small infections on the trunks can be removed by cutting off the dead barks.
- Verticillium wilt is a disease where the branches of the tree wilt or die. Very rarely the infected sapwood will be stained dark or olive green in colour. 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 the tree if the tree will outgrow the infections.
- Scorch as the name indicates, occurs during very high temperatures accompanied by wind. The reasons for this disease are not enough water or diseased roots. Scorch due to dry soil or not enough water can be treated by watering the tree, whereas scorching due to diseased root cannot be cured this way. Symptoms of scorch are brown dead areas between veins in the leaf.
- Tar spot and other leaf spots are other concerns with the Amur Maple, but they are not serious diseases.
- Iron chlorosis develops as a result of iron deficiency when the plants grow in alkaline soils or poorly drained soils
How to protect the Amur Maple (Acer ginnala) from pests and diseases?
- For the Yellow bellied sapsucker, you can use woodpecker deterrent methods to avoid them from making holes on the tree trunk, thereby maintaining a healthy trunk for the tree.
- Visual deterrants - aluminium foils or tapes, or balloons with faces of owl, noisy tins, anything that is shiny and noisy
- Auditory deterrants - devices that create a noise (similar to their predators) when they sense any movements
- Using nets - covering the branches with hardware cloth. Enough space has to be left between the branch and the cover so that the woodpecker does not peck through the covering
- Sprays - there are certain non-toxic chemicals or sprays that can be sprayed on the land around the tree, These create an odour that the woodpeckers do not like and hence will deter them
- Woodpecker deterrant hole fillers - these are used to fill the pecked holes and when the woodpecker pecks on them, they create a foul taste and odour which will deter the woodpecker
- Adding bird reflective objects is another tactic to frighten the woodpeckers
- Aphids, scales and borers can be controlled by spraying them with insecticides or horticultural sprays, whichever is relevant to keep them under control or eliminate them.
- Diseases that occur in the Amur maple can be controlled or avoided by proper pruning, looking after the health of the tree, watering the tree well and by providing proper fertilisers.
Uses of Amur Maple (Acer ginnala):
- They are used as ornamental plants / trees in northern parts of Europe and North America in patios and parks for their brilliant foliage and fruits / seeds in Autumn season.
- Due to their short and smaller size, they can be used as an excellent privacy screen on decks and patios and they fit into almost any landscape.
- They can be used as parkland trees or in public gardens or on highways for their beautiful foliage.
- They can also be pruned and used in hedges.
- They can be used as tree lawns or as a specimen tree
- They can be used in streets that lack a sidewalk
- They make good bonsais and are suitable for xeriscaping
Medicinal and culinary uses:
- Their extracts have astringent properties and are used in cancer research
- The young leaves of the Amur Maple have been used as a tea substitute
- The dried leaves of the Acer ginnala are used to prepare black, blue and brown dyes. These dyes contain quercetin (a dye stuff) and around 30% of tannin.
Agro forestry products:
- They are used for their sugary sap
- The leaves are used while packaging apples and other root-crops to help keep them fresh.
- Used as tree strips for windbreaks, using these as windbreaks help handle the impact of winter storms.
- Planted to protect livestock, enhance production and to prevent soil erosion.
- They are used in various conservation methods and as windbreaks in farms which have buildings near them
- Used as riparian plantings - these are vegetated areas next to water resources that protect water resources from pollution and provide bank stabilization. They also provide space for aquatic and wildlife habitat
- The leaves are eaten by deer and rabbits and the seeds are eaten by squirrels
- They provide home or cover for songbirds
Facts about the Amur Maple (Acer ginnala):
- The name of the tree comes from the Amur river in the Amur valley that divides China and Russia.
- The Amur Maple has gained the Award of Garden Merit from the Royal Horticultural Society in the UK
- They are best known for their vibrant fall colours.
- They are commonly sold under the name Amur Maple but are sometimes sold as Siberian Maple.
- They are an invasive species that are non-native, but naturalised in parts of North America. The invasive nature depends on the area or region where they grow.
- The beauty of the fall colours of the leaves depends on the amount of sunlight the tree gets and soil conditions. Brilliant colours are portrayed if it gets full sunlight and healthy soil.
- They are drought and wind resistant
- Their growth is slow and they remain small when mature and hence can be planted below or close to power lines on the streets.
- Extracts of Acer species have been found to be toxic to pests like insects.
- This species of maple is found as a suitable one for bonsai in countries like Japan and others.
- The Amur Maples were introduced in North America in the 1860s
- They thrive well in colder climates up to -38 degree Celsius and live for around 20 to 30 years or even more till 50 years if they are in healthy soil and environment
- They are not toxic to livestock or other plants and trees.
- It requires a minimum of 130 frost free days a year.
- These invasive species are sold in the markets while many others spend time and money removing them, as they ruin native wildflowers and wildlife habitat.
- They can be injured by weed-killers like plant growth regulators
- Amur maples have fragrant flowers
Different cultivars or varieties of the Amur Maple:
They have different cultivars like
- Flame Amur Maple – Acer ginnala ” Flame”
- Embers Amur Maple – Acer ginnala “Embers” that have red leaves and red fruits (samaras)
- Red wing Amur Maple – Acer ginnala ‘Red wing’ or “Red fruit” that has yellow or red leaves with red fruits (samaras)
- Compact Amur Maple – Acer ginnala “Compactum” or Acer ginnala “Bailey compact” has compact, dark green leaves and round crown without need for pruning. This is a pest free cultivar of a smaller size
- “Durand’s dwarf” is a shrub type plant with branches denser than compactum
Threats from the Amur maple and how to control it:
- Due to its invasive nature, it can inhibit growth or displace native shrubs and understory trees in the open woods
- It can shade out native grasses and herbs in the savanna habitat.
- It is an abundant seed producer and re-sprouts easily from cut stump
- They can be controlled by burning them but cannot be eliminated.
- Small infestations of the Amur maple can be removed easily
- Cut stumps of the Amur maple can be treated with glyphosate or, bark spray treatment around the stem with triclopyr can help to kill the plant or tree
Crimson leaved maple
Amur maple can be used for the following styles of planting:
Most of these styles are preferable for bonsai.
Formal Upright - the plant stands upright without slanting and with a tapering trunk
Informal upright - the plant is upright with the apex of the plant above the base, but still grows upwards with twists or curves in the branches
Slanting - the plant is in a slanting position in upright style, with the apex of the tree to the left or right of the base
Cascade - the plant has branches that fall down like a cascade with the apex of the tree falling below the base of the pot
Semi-cascade - part of the plant has a cascaded style and part of them an informal upright style
Root-over-rock - the roots of the plant are over a rock, clasping the rock
Clinging to a rock - the roots of the plant are close to the small rocks in the pot following the contours of the rocks.
Twin trunk - there are two trunks emerging from the base of the plant or tree
Group planting - group of plants or trees planted together
Saikei - miniature landscapes with bonsai
Although an invasive species in some parts of the world, would you ever like to grow an Amur Maple for any of its beneficial purposes?
I would appreciate your thoughts, ideas, experiences, knowledge and feedback on this hub. The information provided here are after a thorough research through various sources. This is not an advice from an expert, but general information on how to grow the Amur maple trees. Please feedback on any errors if any.
I hope you found this hub useful and interesting. Thank you for reading. I would like to hear from you.