Acer

( AY - ser )

At-A-Glance Information

Commonly referred to as Maple, this genus of trees and shrubs needs full sun or partial shade, and moderate to regular water, though this can vary somewhat depending on the species grown. They are native to Asia, Europe, Africa, and North America. These trees are admired for their brilliant fall colors and delicate foliage. All Maple trees produce winged seed pods, and do well in the Pacific Northwest and Northern California. The generic Maple species is featured as the official arboreal emblem of Canada. Take care when planting these trees in the garden, as some species are toxic to humans and animals.

Acer Species and Varietals

The genus Acer includes 132 species, and is a member of the Soapberry plant family Sapindaceae, making them relatives of Lychee and Horsechestnut (Aesculus). The best growing zones for Maple vary depending on the species. For more information, consult the descriptions below. To find your zone, click here: Zone Map.

Acer buergerianum (Trident Maple)
This species of Maple tree grows best in zones 2-9, 14-17, 20 and 21. It is native to China and Japan and grows to be 20-25 feet tall and wide. Glossy green leaves are pale underneath, and fall color is usually red but can be orange and yellow as well. Older wood has flaky bark. Low, spreading habit, but can be pruned into a formal tree. Great for bonsai.
Acer campestre (Hedge Maple)
This tree grows best in zones 2-9 and 14-17. This native to Europe and Western Asia is a slow grower, reaching 70 feet tall in its native environment and about 30 feet tall and wide in cultivation. Dense, compact shape, with leaves that are green above, downy underneath and turn yellow in the fall. Varieties are outlined below.
'Carnival'
Slow grower to 10 feet tall and wide. New leaves are pink, and mature to green with white margins.
'Metro Gold'
35 feet tall, 20 feet wide with great fall color. Does not produce many seedlings.
'Postelense'
Spreading habit, reaches around 10 feet tall. New leaves are gold, and turn lime green in summertime.
'Pulverentum'
This variety has variegated leaves, and gets to 12 feet tall in about 10 years.

​Acer capillipes
This tree grows best in zones 2-9, 12, and 14-24. Native to Japan, this Maple grows to 30 feet tall and wide. Branches are red when young and gradually turn brown with white stripes. Leaves are red when young, and turn red in fall when mature. Needs partial shade in warmer climates.
Acer circinatum (Vine Maple)
Can be a shrub or a tree. This Maple grows best in zones 14-17. Grows well on moist stream banks and in coastal mountains. In shaded areas, it is multi-trunked with a spreading habit, and in the open, it forms a small tree 5-35 feet tall with either one or several trunks. Leaves are tinted red when new, and turn green with maturity. In fall, leaves are red, orange, scarlet or yellow. Spring flowers are reddish-purple. Varieties are outlined below.
'Monroe'
Deeply lobed leaves. 
'Pacific Fire'
Waxy, fire-red bark in winter and yellow fall foliage tinted with orange. Gets to 12 feet tall; slow grower.
'Pacific Purple'
Leaves are bronze-green when young and turn purple in summertime. Red leaves in fall.
'Sunglow'
Slow-grower to 6-10 feet tall and wide. New growth is orange-pink.

​Acer x conspicuum 'Phoenix'
This tree grows best in zones 2-6, 15-17, 20 and 21. This is a garden-size tree that gets to about 20 feet tall with a shrub-like habit. Green leaves turn yellow in fall. Branches are yellow in the summertime, coral-red with white stripes in winter.

​Acer davidii (David's Maple)
This tree, native to central China, has snake bark that is shiny green striped with silvery white. Leaves are glossy green and deep-veined, turning yellow, red-orange, and purple in fall. New foliage is bronze. Greenish yellow flowers bloom in spring. Needs part shade in warmer areas. Best in zones 2-6, 15-17, 20 and 21. Grows to 20-35 feet tall and wide.

​Acer griseum (Paperbark Maple)
This maple tree grows best in zones 2-9 and 14-21. Gets to 25 feet or taller, but about half as tall and wide in gardens. Reddish bark peels away in paper-thin sheets. This species is late to leaf out in spring, and has dark green leaves above, silvery beneath. Small red flowers bloom in spring followed by showy red seed pods. Brilliant red foliage in autumn.
Acer japonicum (Fullmoon Maple)
Can be grown as a shrub or tree, this native to Japan is best when grown in zones 2-6 or 14-16. Gets 20-30 feet tall and equally wide. Fall foliage is red, orange, and golden. Needs regular watering and partial shade in warmer climates.
'Aconitifolium'
(Fernleaf Fullmoon Maple)
Fast grower to about 15 feet tall and 20 feet wide. Leaves are deeply cut.
'Aureum'
(Golden Fullmoon Maple)
Best in zones 3b-6 and 14-16. Gets to 20 feet tall and wide. Pale gold leaves in spring, pale chartreuse through summer.
'Ed Wood'
About the same size as Acer japonicum 'Aconitifolium', but with more vigorous growth.

​Acer macrophyllum (Bigleaf Maple)
This tree grows best in zones 2-9 and 14-24. This is native to stream banks and canyons in southern Alaska and Southern California. This is a dense shade tree and gets to 30-75 feet tall and 30-50 feet wide. Leaves are green and turn yellow in fall; color is more brilliant in cooler temperatures. Tassels of greenish-yellow spring flowers followed by winged seeds that hang in chains. Resistant to Oak Root Fungus.
Acer negundo (Box Elder)
Grows best in zones A2, A3, 1-10 and 12-24. This tree is native to most of the United States, and seeds readily. Considered invasive in some areas. Fast growing to 60 feet tall and as wide. Leaves are green, and turn yellow in fall. Varieties improve on the issues of this species:
'Sensation'
Male form (no seeds, so it does not attract Box Elder Bugs), and is slower-growing to 40 feet tall and 30 feet wide. Does not sucker. New growth is bronze, fall color is pink-red.
'Variegatum' (Variegated Box Elder)
Not as large or 'weedy' as the species, and has a combination of green and creamy white leaves.

​Acer nigrum (Black Maple)
Grows best in zones 1-10 and 14-20. Resistant to heat and drought. Light green leaves that turn yellow in fall. Variety 'Greencolumn' can reach 65 feet tall and 25 feet wide.

​Acer palmatum (Japanese Maple)
This can grow as a shrub or tree, best in zones A3, 2b-10, 12 and 14-24. It is native to Japan and Korea. Slow grower to 20 feet tall and equal width. Airy and delicate with deeply cut leaves. Spring growth is red, summer leaves are green, fall foliage is scarlet, orange or yellow. There are many varieties of Japanese Maple available, generally divided into Dissectum and Non-Dissectum types. They are listed below.
Acer palmatum dissectum
Sometimes called lace-leaf maples, these are slow growers to about 6-8 feet tall and 8-12 feet wide. Almost all have an umbrella-form when mature, with sinuous trunks and branches.
'Contorta'
Gets 8 feet tall and 12 feet wide. Finely divided leaves and a weeping growth pattern. Yellow-orange fall color.
'Crimson Queen'
Small, shrubby Maple, to 9 feet tall. Holds leaves through the summer and turn scarlet in the fall before they drop.
'Dissectum'
​(Laceleaf Japanese Maple)
This 6 foot tall, 12 foot wide shrub has drooping branches and green bark. Pale green leaves turn gold in fall.
'Emerald Lace'
​Small tree with a cascading look, to 8 feet tall and 10 feet wide. Has dark green leaves that turn bright red in fall.
'Ever Red' 
​('Dissectum Nigrum')
7-foot mound with weeping branches and tinged purple leaves that turn crimson in fall.
'Orangeola'
Compact, to 6 feet tall and a little less wide. Orange new leaves turn green with age. Orange-red fall color.
'Seiryu' (Threadleaf Japanese Maple)
Upright, to 10-12 feet tall and wide. Lacy leaves are red in spring, green in summer, and gold with a bit of crimson in fall.
'Viridis'
6 feet tall, 8 feet wide with a clumping habit. Lacy green leaves turn golden orange in fall.
'Waterfall'
4-6 foot tall mound that gets twice as wide. Green leaves are fern-like. Brilliant yellow-gold fall color.
Acer palmatum
These Non-Dissectum types are, generally, more upright and larger than dissectum-type maples, and they do not have 'lacy' leaves.
'Atropurupureum'
(Red Japanese Maple)
Gets to 20-30 feet tall, has dark red-wine summer color, red leaves in fall.
'Bloodgood'
Vigorous grower to 18 feet tall with deep red spring and summer leaves that turn scarlet in fall. Dark red bark.
'Burgundy Lace'
​Gets to 12 feet tall and 15 feet wide. Leaves are deeply cut, and branches are bright green.
'Butterfly'
Grows 10 feet tall and 5 feet wide. Light green leaves in spring have pink margins and mature to green with creamy white variegation. Magenta tint in fall.
'Crimson Prince'
Gets 20 feet tall and 22 feet wide. Purple-red foliage that turns red in fall. Tolerates heat and humidity.
'Emperor I' ('Wolff')
Vigorous, upright growth to 20-25 feet tall, with red leaves that hold their color into summer. Deep crimson fall foliage.
'Fireglow'
Grows to 15-20 feet tall and has red leaves that do not fade in summer's heat.
'Osakazuki'
Upright growth to 20-25 feet tall with large leaves that turn to crimson in fall. Tolerates sun and heat.
'Sango Kaku' ('Senkaki')
(Coral Bark Maple)
Vigorous grower, to 20-25 feet tall and 18-20 feet wide. Green summer leaves are slightly gold and turn yellow in fall.
'Shaina'
Dwarf variety of 'Bloodgood'; gets up to 5 feet tall with dark red-wine summer leaves and red fall foliage.
'Shishigashira' 
(Lion's Head Maple)
Upright growth to 12-20 feet tall with deeply cut leaves. Slow grower; great choice for a bonzai.

​Acer pensylvanicum (Striped Maple)
This tree grows best in zones 3-6, 15-17, 20 and 21. Native to North America, this snakebark maple gets up to 25 feet tall and 20 feet wide. Bark is vertically striped with green and white. Fall foliage is yellow.
Acer platanoides (Norway Maple)
This species of Maple has many varieties and grows best in zones A2, A3, 1-9 and 14-17. This tree is native to Europe and western Asia, and gets 50-60 feet tall and about as wide. Leaves are deep green above and lighter beneath. Leaves are yellow in fall. Small, greenish-yellow flowers bloom in spring. The species has some issues, including aggressive roots, self-sowing seedlings, and sooty mold. Varieties are outlined below.
'Columnare'
Slow grower, with a narrow habit, gets to about 20 feet wide and 50-60 feet tall.
'Crimson King'
Purple foliage until leaves drop off, slow-grower. Great in the northwest and foothills of California.
'Crimson Sentry'
Compact growth to 25 feet tall. Foliage is dense and bright red.
'Deborah'
Gets to 45 feet tall and 40 feet wide, and has purple-red leaves in summer. Bronze fall foliage.
'Drummondii'
Leaves on this species are edged with silver-white. Needs some shade in warmer climates.
'Easy Street'
Similar to 'Columnare' but a little wider and more pyramid-shaped. Foliage is dark green and turns yellow in fall.
'Emerald Queen'
Fast growing, takes on an ovular shape 40-50 feet tall and 25-30 feet wide. New growth is reddish, and matures to glossy green, turning yellow in fall. 
'Fairview'
Gets to 45 feet tall and 35 feet wide. Reddish-purple new growth matures to bronze-green. 
'Globosum'
Slow-grower with a dense habit, eventually reaches 20-25 feet tall. 
'Parkway'
Gets to about 25 feet wide, with a dense canopy.
'Princeton Gold'
Oval-shaped tree to 35 feet tall, with golden yellow leaves that hold color all season, turning bright gold in fall.
Acer pseudoplatanus (Sycamore Maple)
This tree grows best in zones 1-9 and 14-20, and is native to Europe and western Asia. Gets to 40 feet tall or more and almost as wide. Leaves are prominently veined and dark green above, paler below. No particular fall color; varies by variety. Types are outlined below.
'Atropurpureum' ('Spaethii')
Leaves are rich purple on the undersides.
'Esk Sunset' ('Eskimo Sunset')
Leaves are blotched green, salmon, and light yellow on top, purple-red underneath.
'Leopoldii'
Gets to 50 feet tall, and has green leaves interestingly variegated with cream. 
'Prinz Handjery'
Leaves are pink when new, and mature to develop purple undersides. Grows to about 10 feet in as many years. 

​Acer pseudosieboldianum
This tree grows best in zones 2-10 and 14-18, and is a native to Manchuria and Korea. It is a rounded tree growing to 20 feet tall and wide. Variety 'Northern Glow' (pictured left) is a hybrid of this species with A. palmatum, and is a graceful, spreading tree to 20 feet tall and 24 feet wide with brilliant orange-red foliage in fall.
Acer rubrum (Red Maple, Scarlet Maple)
This tree grows in zones A2, A3, 1-9 and 14-17. Grows quickly to 60 feet tall and 40 feet wide. Red twigs, branches and buds with showy flowers. Leaves are shiny green on top, pale underneath. Fall foliage is brilliant scarlet in cooler areas. Tolerates many soils. Varieties outlined below.
'Armstrong' (A. x freemanii)
Narrow tree (15 feet wide) that grows to 50-60 ft. tall. Poor orange-red fall color.
'Autumn Blaze'  ​(A. x freemanii)
Dense crown with amazing orange-red fall color.
'Autumn Fantasy' (A. x freemanii)
​Dense oval shape, with beautiful red fall foliage.
'Karpick'
Narrow (20 feet wide), 50-60 feet tall. Red twigs and yellow to red fall foliage.
'New World'
30 feet tall, 15 feet wide. Bright red-orange fall leaves.
'October Glory'
Tall, round-headed tree.
'Redpointe'
Grows quickly into a 45 foot tall, 30 foot wide tree that is pyramid-shaped with green leaves that turn bright red in fall.
'Red Sunset'
Upright, vigorous growth with an interesting branching pattern.
'Scarlet Sentinel'
​Columnar form, grows to about 25 feet wide. Fast grower.
'Somerset'
Narrow, oval shaped tree with brilliant long-lasting red fall color.
Acer saccharum (Sugar Maple)
Grows best in zones 1-10 and 14-20; Native to eastern North America. This tree is the source of Maple Sugar. Grows to 60 feet tall and 40 feet wide. Leaves are green above and pale underneath. In cold-winter climates, fall color is yellow, orange, and deep scarlet.
'Apollo'
Small, 25 feet tall by 10 feet, columnar growth. Yellow-orange to red fall color.
'Autumn Fest'
Grows to 50 feet tall and 35 feet wide. Upright ovular growing tree; Early orange-red to red fall foliage.
'Autumn Splendor'
Grows to 45 feet tall and 40 feet wide. Heat and drought tolerant. Great choice for the Southwest. Orange-red in fall.
'Bonfire'
Fast-growing to 50 feet tall and 40 feet wide. Fall foliage is orange to red.
'Fall Fiesta'
Gets to 50 feet tall and 40 feet wide. With orange, red, and yellow fall foliage. 
'Flashfire'
​Grows to 45 feet tall and 40 feet wide, and fall foliage is bright red.
'Green Mountain'
Tolerant of heat and drought; this tree has yellow-orange to reddish-orange fall foliage.
'Legacy'
Drought-resistant and fast-growing. Fall color can be red or yellow-orange.

​Acer shirasawanum 'Aureum' (Golden Fullmoon Maple)
Shrub or tree that grows best in 3b-6 and 14-16. Gets to 20 feet tall and wide. Leaves are pale gold in spring and pale chartreuse in summer. Needs to be planted in partial shade. Variety 'Autumn Moon' has burnt orange new growth, and orange-red fall foliage.

​Acer tataricum (Tatarian Maple)
Can be grown as a shrub or tree in zones A2, A3, 1-6 and 14-16. Native to southeastern Europe and western Asia; this plant gets to 20-25 feet tall and has red-winged seeds in summer. Fall foliage is yellow-red-brown. Varieties include 'Hot Wings' with bright red seed pods in summer, and 'Rugged Charm' with a narrow, ovular form.

​Acer tataricum ginnaia (Amur Maple)
This species, native to Manchuria, northern China, Japan, and Korea, grows best in zones A1-A3, 1-9 and 14-16. Gets 15-20 feet tall with clusters of small, fragrant yellow flowers in springtime followed by red seed pods. Fall foliage is red, especially red in varieties 'Flame', 'Red November' and 'Red Rhapsody'. This species needs regular waterings during hot periods.

​Acer truncatum 
This tree grows best in zones A2, A3, 1-9 and 14-23. This native of China grows quickly to 25 feet tall with equal width. New leaves are purple-red and mature to green. Fall foliage is yellow to red-orange. Great as a lawn or patio tree. Tolerates heat and drought. Hybrids of this species are popular, and are outlined below.

​Acer 'White Tigress' (White Tigress Maple)
Can be grown as a shrub or tree; Best in zones 2b-7 and 14-17. This is a multi-trunked varietal that has green bark striped with white and gray. Large green leaves turn yellow in fall. 

Caring for and pruning Acer Trees

Plant your Maple tree in an area that gets partial to full sun. These trees should be getting between 4 and 6 hours of sun per day for best performance, though this varies somewhat depending on the species; some will need more, others less. Make sure to check the species-specific light requirements before planting. Maples generally do well in soil that is well-draining and that has a acidic pH of between 5.0 and 7.0, though this can also vary depending on the species. Amend soil with plenty of organic matter before planting. Mulch around the base of the tree after installing to discourage weed growth, moderate soil temperature, and increase soil moisture retention.. Water your tree regularly, especially during warmer times of the year. Fertilize in early springtime with a slow-release balanced fertilizer. As always, avoid over-fertilizing.

Pruning Acer trees is straightforward; it is best done in the springtime before new growth begins to pop out. At this time, remove any dead, damaged, or crossing branches and trim to maintain an attractive shape and size. Acers can be grown both in-ground and in containers. If your tree is a container specimen, ensure that there are adequate drainage holes in the pot, and provide well-draining soil to prevent root rot diseases from taking hold. Water regularly, and fertilize during the active growing season to support new growth. Repot your Acer every 2 to 3 years to ensure that it is not becoming root-bound. Although Acer trees are considered to be hardy, they may need some protection from prolonged periods of frosty temperatures.

​Harvesting Maple Trees
The product Maple Syrup is made from the sweet sap of the Sugar Maple (Acer saccharum). In springtime (late February or early March). A planted crop of Sugar Maples is referred to as a Sugarbush. To be able to be tapped for its sap, a tree must be around 40 years old, at least 10 inches in diameter, and be in good health. If done correctly, tapping a tree does no harm to the plant itself; a healthy Sugar Maple can provide sap for creating maple syrup for upwards of one hundred years if proper procedure is followed. During the tapping season, which commonly lasts between four and six weeks, trees can be tapped for around 10 gallons of sap, yielding about a quart of final product. The season begins when temperatures are not as extreme as they were in the winter months, and water is an abundant resource.
Harvesters of maple sap use a device called a spile, which is inserted into a drilled hole. The sap that is excreted by the tree through this hole either falls through the air into a bucket or travels through an attached tube that is connected to a pipeline. After the sap is collected, it is brought to a processing area where it is boiled and reduced into maple syrup. The maple-tapping season varies in length each year, depending on the weather conditions. Once buds on the branches of these trees have started to sprout, tapping season is finished.

Propagation

Acer can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Maple, follow the instructions below:

Propagating Acer by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots. 
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Acer by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds. The seeds on Acer plants are pretty easy to find; see the photos below for more information. Once they have dried out they can be harvested. Collect as many as you can, and place the paper bag in a dry, cool, dark area until you are ready to work with them. The seeds do not need to be separated from their wing in order to be planted, but they should be separated. Each winged piece will have two seeds; simply rip or cut it in half.
  3. The seeds need a cold snap to germinate; the best way to replicate these conditions is to place your seeds in a sealable bag or container filled with moistened peat or sphagnum moss and place that container in the refrigerator for three months.
  4. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  5. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Acer seeds are 'winged', allowing them to float through the air away from their parent tree.
Acer seeds.

Problems and Pests

Acers are susceptible to the following pests and diseases:
  • Aphids
  • Scale Insects
  • Caterpillars
  • Leaf Spot
  • Tar Spot
  • Powdery Mildew
For information on managing these plant issues, see the following links:
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Gallery

​Acer capillipes has beautiful, striped bark.
Chains of flowers hang off the branches of Acer macrophyllum.
Maple trees can either be grown in the ground or in containers.
Maple trees bring beautiful fall color to many gardens.
Plant Maple trees along pathways where their canopies can be admired from below.
Maple trees can add softness and color to more modern-style gardens.

Videos

All about Maple Trees.
How to harvest Maple Syrup.
Learn how to properly plant a container-grown Maple.
How to propagate these gorgeous trees.
All about growing Maple trees from seed.
A great example of how to use Maples in the landscape.
Tips and tricks for growing beautiful Japanese Maples.
Learn all about Sugar Maple trees.

Resources

How to Take a Cutting from an Acer Tree
How Maple Syrup is Made
Wikipedia: Maple
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 128 - 132, Acer 
If you have any questions, comments, concerns, or photos you’d like to add to the gallery, please let me know by sending me a message using the button below!
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