With an extensive variety of growth forms, distinctive leaf shapes, and striking autumn color, the Japanese Maple is the must-have specimen tree. Read on to learn more about this magnificent species, and how to cultivate your own.
All About the Japanese Maple Tree
Also known as “Acer palmatum”, this species contains a wide range of ornamental, deciduous trees. You’ll see dwarfed and weeping varieties as well as full-sized, wide-branching marvels. Their elegant form and vivid color combinations embody their Far Eastern roots. Best of all, they integrate easily into both new and mature gardens in almost any decent well-drained soil.
The palmate leaves of the Japanese maple tree are among its most renowned features. They’re deeply lobed color chameleons throughout the seasons, creating a remarkable, ever-changing focal point in any garden.
Today I’m looking at the different growth forms of the Acer genus, and finding out how to pick the right type of Japanese maple tree for your own garden. To start, let’s take a look at the two most common types available, and their distinguishable characteristics.
The Acer japonicum species consists of a selection of deciduous, small bushy trees or shrubs. These are fully frost hardy with rounded, lobed palmate leaves.
In contrast, the Acer palmatum species is comprised of deciduous, bushy-headed trees or shrubs, often broader than they are tall. These species are also fully frost-hardy with deeply lobed, palmate leaves. There are simply hundreds of cultivars to choose from, all bringing a highly sought-after, individual quality to the garden.
Both species above offer the enthusiast a variety of growth habits, including upright, mound-forming, and weeping.
Generally, Acers are known to be slow-growing. In fact, some species have the potential to reach up to 8 meters tall in 50 years. However, most are smaller in size, making them the ideal choice for smaller gardens and container planting.
History of the Acer palmatum species
The Acer palmatum is native to Japan, and has been cultivated in its homeland for centuries. In the late 18th Century, Swedish botanist Carl Thunberg came across this unusual tree whilst travelling in the far East. He recorded his findings through a set of drawings, which he secretly sent out of the country.
Thunberg named the species “palmatum”, with reference to its hand-shaped, palm-like leaves. The first specimen tree reached Britain in around 1820. Since then, Japanese horticulturalists have spent years developing different maple cultivars from Korea and China.
Nowadays, numerous Japanese maple tree cultivars are intensely popular throughout Europe and Northern America. Their widespread following prefers the red-leafed varieties, and the delicate “dissectum” species, with their intricate leaves and cascading growth habit.
Growth Habit of the Acer palmatum tree
Japanese maple trees can be upright, pendulous or cascading in structure. In fact, their habit can be as diverse as their leaf colors. In their natural habitat, they’re found growing across hillsides in Japan, Korea, Mongolia, and even Russia. They can reach between 25 and 30 feet tall, and often grow as a forest canopy under-story.
They receive perfect amounts of light, shade and nutrients from the forest floor to thrive in this environment. Their mature bark is smooth and grey-green in hue, with contrasting young growth of green, pink and even red.
When cultivated for a Western garden, many specimens will reach the size of a small tree. In contrast, others may never grow taller than 4–5 feet in height, with a spread of maybe double that.
Let’s have a look at some of the most well-known and decorative ornamental maple trees available. I’ll list each under their common growth habit.
Japanese Maple Trees with Upright Forms
Acer palmatum “Osakazuki”
Here we have one of the most intense, long-lasting autumnal coloring of all the Japanese maple trees. This is a dramatic, small tree reaching a height and spread of 4m x 3m. The Osakazuki is a tough, fairly fast-growing specimen with a rounded upright form and an open habit.
Its leaves are green throughout the spring and summer, slowly transforming as autumn approaches. Then, you’ll see the richest shades of golds, oranges, copper, and fiery red imaginable. This is a truly bewitching specimen tree, sure to cause a stir. It’s also perfect for a lightly shaded spot in a sheltered location.
Acer palmatum “Bloodgood”
This is the hardiest of all Japanese maple trees, and one of the most popular red-leaved cultivars. When it’s mature, you can expect a height of around 20 feet tall. It has an upright, branching habit with substantially lobed, glorious blood-red leaves.
As new growth emerges in the springtime, the leaves are deep pink, resulting in striking spring color. Leaves turn a more purple-red in the summer sun until becoming an autumnal shade of crimson-red. This is a great, reliable showpiece for a medium-sized garden, with a spread of up to 12 feet. “Bloodgood” dislikes heavy or water-logged soils and prefers a sunny position where its leaf color will be enhanced.
Acer palmatum “Sango-Kaku”
Also known as The Coral Bark Tree, the “Sango-Kaku” has the unique appeal of brightly colored coral-pink bark throughout the drab winter months. In spring, young palmate leaves grow yellow-orange in color, gradually turning shades of lush green throughout the summer months.
Autumn brings shades of soft, buttery yellow foliage until early winter, when all the leaves fall. The subsequent cold spell triggers the bark and stems to turn a vibrant shade of coral pink, until the following spring.
In my opinion, this is one of the most superb, easy-growing, small Acer trees. It will reach a height and spread of around 4m x 2m, and offers year-round interest to the garden.
Acer palmatum “Westonbirt Seedling”
This is a rare, long-lobed variety of Japanese maple that was first grown at the Westonbirt Arboretum in the U.K.’s Costwolds area. It has an upright habit and medium growth rate, comfortably reaching a height and spread of 4m x 3m in maturity.
New green growth emerges with hint of red in springtime, turning a fresh apple-green throughout the summer months. Autumn brings red and orange hues to the existing green leaves, resulting in a magnificent autumnal show. Overall, a worthy addition to any medium-sized garden with a sunny or partly-shaded, sheltered spot.
Mound forming Japanese Maple Trees
Acer palmatum “Shindeshojo”
For the first of our mound-forming cultivars, I have chosen this elegant, small tree also known as the “Spring Ruby Tree”. This has a bushy, wide-growing stature with elegant upright branches and reaches a mature height and spread of about 2.5m x 2.5m.
Its young, spring foliage appears a brilliant shrimp-pink color, gradually turning green towards the summer months. Note that it keeps the red and shrimp-pink leaf margins. As autumn approaches, it brings a color sensation as leaves turn shades of orange, red, and bronze. A true gem in the Japanese maple genera, perfect for both container and garden planting, with best color achieved in a slightly shaded spot.
Acer palmatum dissectum “Crimson Queen”
The “Crimson Queen” is one of the larger bushy shrubs available, reaching around ten feet tall in both height and spread. Its branches are pendulous, gracefully arching whilst bearing rich red, deeply incised, palmate leaves from springtime.
In the summer, the delicate leaves turn a purple shade of red until autumn, when they reach a brighter, scarlet shade of red. This is a truly lovely cultivar with a cascading form and vibrant year-round color. It grows best in a full sun or partly shaded spot, and is especially effective in a mixed border.
Acer palmatum dissectum “Garnet”
“Garnet” is one of the “dissectum” group of Maple trees. These have very fine, almost lace-like leaves and are less cold-tolerant than the standard palmatum cultivars. However, their beauty outweighs their tenderness, bringing me to my personal favorite in this category.
I love the gentle, arching form of this Japanese maple cultivar and its eye-catching, deep red-purple leaves that turn to fiery flame-red in the Autumn. As a medium sized shrub, you can expect a height and spread of 1.5 m x 2.5 m in a mature specimen, making them an easy option for container growing as they will remain quite short and stout.
Acer palmatum dissectum “Orangeola”
This “Orangeola” cultivar is a relatively recent addition. It has the same lacy-textured leaves as that above, with a similar height and spread of 1.2 m x 2.4 m. This is a much-admired Japanese maple tree with a curved, mounding form and vibrant, blazing orange leaves throughout the springtime.
In summer, the delicate leaves turn a more bronze-red color, gradually brightening towards the autumn when they reach a fiery orange shade. This is another good specimen for container growing, bringing the garden to life throughout the seasons.
Weeping Japanese Maple Trees
Acer palmatum dissectum “Ever Red”
This dwarf Japanese maple has an elegant, weeping form with the delicate, feathery-fine leaves so treasured in the “dissectum” species With a compact height of just a meter and a mature spread of 1.5m, the “Ever Red” is the perfect choice for the Acer enthusiast with a small garden.
Grow it in part-shade, and you’ll see new foliage growth appear in shades of crimson red. In summer, that red matures into a rich burgundy. In autumn, the lacy leaves turn varying shades of bronze with an almost golden appearance. This is a wonderful small Acer that packs a colourful punch, and is especially stunning against conifers like cedars in a Japanese themed garden.
Acer palmatum “Orido-Nishiki”
This fast-growing cultivar is one of the best variegated Japanese maples. In spring, new growth emerges with a pretty cream and pink variegation on and around the palmate leaf margins. As the season progresses, the substantial leaves darken to deep pink and white variegation on predominantly green leaves.
In autumn, the leaves take on shades of yellow and gold, resulting in a spectacular sight. With a height and spread of around 3 meters and a preference for partial shade, this stunning is best suited as a specimen tree or in a mixed border. With such wonderful colors, I personally would position it in full view.
Acer palmatum dissectum “Viridis Tree”
My final choice is a low, weeping Japanese maple with bright, lime-green, deeply dissected, lacy foliage and a height and spread of about 2m x 3m. The bright green foliage turns intense shades of gold, red and orange as the autumn comes close, contrasting tastefully amidst the surrounding trees.
This cultivar has a particularly good form, with a rounded crown and bright thread leaf maple leaves. The perfect addition to a smaller garden, best suited to a semi-shaded, sheltered position.
Choosing your Japanese Maple Tree
When choosing your tree, be sure you have ample planting space for it to mature. Always choose a tree that looks healthy and has a balanced framework of branches. If this means taking a good look at all available trees, then so be it.
Successful Growing Tips
Planting your Japanese Maple Tree
The ideal time of year to plant your Japanese Maple tree is between October to March. Dig a large enough planting hole, twice the size of your root-ball and once planted, back-fill the soil adding soil conditioners as you go. Heel-in your newly planted Maple tree and water well.
The Acer palmatum species will grow in any well-drained soil, providing it’s rich in nutrients and drains easily. That said, they seem to prefer a slightly acidic soil, which can be obtained by adding a little sand and well-rotted garden compost or organic matter.
Try to choose a site that’s sheltered and away from strong winds as these can damage your Japanese maple tree. They like plenty of space for their root systems to grow, without competing against other trees. As a result, they should be shallow planted with only an inch of soil over the main root system.
Red-leaved cultivars will need plenty of sunlight to help develop their rich coloring. The green-leaved forms also tolerate a sunny site, but prefer indirect, filtered sunlight that will avoid leaf scorch damage. Variegated cultivars need to be planted in a partially shaded site because direct afternoon sunlight will also cause scorch damage.
Most Acer trees are hardy from zone 5 to 8, with some cultivars tolerating zones 4 and 9 too. Sun scorch is the main problem in very hot areas, whereas very cold temperatures can sometimes cause branch die-back.
The winter cold will help your tree bud-up for the following year, hence areas with tropical temperatures are not really a suitable growing environment
Caring for your Japanese Maple Tree
Once planted into the ground, your Japanese maple tree will need to be watered regularly for the first couple of years to help its root systems establish. Container-planted trees will need more frequent watering than those planted directly in the ground. Ensure your potting soil doesn’t dry out, watering well when the top inch of the potting soil is dry to the touch.
You’ll need to top up your compost every year and re-pot your Japanese maple every couple of years. For this, I use an Ericaceous potting compost with around 25% course sand added. When re-potting, it’s a good time to root prune your tree, should it need it.
Feed young trees with a well-diluted liquid feed once every six weeks throughout the spring and summer months. In maturity, this can be changed to a top-dressing of good quality ornamental tree fertilizer, once a year in the springtime.
Regardless of age, container-grown trees will need to be fed once per month throughout the growing period, with a well-diluted liquid feed.
Use bark mulch or garden compost once every springtime. This will transfer nutrients to the roots and help retain moisture in the ground.
There are a host of planting companions for your Japanese maple, and their foliage contrasts well with plants in shades of white, yellow and green.
I have seen some lovely Japanese-themed gardens in the past few years. In a themed or Zen garden, Acers are planted with azaleas, rhodedendrons, conifers, weeping cherries and bamboo. Try under-planting your Japanese Maple Tree with hostas or heuchera. Both these plant families work well in semi shade and contrast beautifully with the maple’s foliage.