Some of the most spectacular trees in the garden are from the Acer palmatum family – Japanese Maples. Some varieties have vivid spring foliage while others are more striking during the fall or winter. Some have yellow leaves, others have green leaves and still others have various shades of pink, red or purple leaves. Fall colors vary from yellow to orange to red. Starting in the early 1600’s many Japanese gardeners started cultivating and breeding Japanese Maples.
There are more than 300 different varieties or cultivars available today, ranging in size from 2′ tall mature trees, to 35′ tall by 40′ wide Japanese maples.
The biggest challenge in using Japanese maples in the garden is choosing the one you like the best because there are so many types, colors, shapes, and rates of growth from which to choose.
Soil Conditions
The ideal soil for Japanese maples is a sandy soil with plenty of organic matter in the soil.
However –Japanese Maples will grow in almost any soil condition as long as the soil does not stay soggy wet. The better the soil conditions are, the better Japanese Maples can withstand other poor growing conditions, such as wind, water related problems, heat stress, insect pests, and diseases.
Planting
Prepare your soil properly before you plant and you will not have as many problems in the future. Dig your hole at least twice as large as the rootball. Mix 20% to 30% Acid Planting Mix with the soil you remove from the hole, along with one cup of Dr. Earth Starter Fertilizer. This fertilizer contains Mycorrhizae and other beneficial bacteria that really help Japanese maples flourish in your soil. Don’t plant your Japanese maple too deep. Keep the graft at ground level, or a little above the ground. It is better to plant your tree too shallow than too deep.
Fertilize your new tree every two weeks for the first two months with Root Starter. Water your tree every day the first week. Make sure that you water it with a hose and not just let the sprinklers water it for you. After the first week, water your tree a least once a week with a hose. Give it 5 to 10 gallons of water each time you water, not just a cup or two. Again, don’t rely on sprinklers to water your tree the first summer.
Fertilizer and pH requirements
Japanese maples will grow in almost any soil pH but they prefer a soil with a slightly acid pH. Unfortunately we do not have acid soil conditions in Utah so you will need to make your soil more acidic. At planting time you can amend your soil with Acid Planting Mix to give your tree a quick start. After the first year you will need to apply sulfur, every spring, around the dripline of your tree to help keep the soil acidic.
High alkaline soil conditions prevent the roots from absorb- ing nutrients and water quickly enough to satisfy their needs, so the trees often show signs of leaf scorch even when the soil is kept moist. High alkaline soil conditions prevent Japanese maples from surviving in some conditions that the tree would otherwise tolerate such as ‘full sun’ areas, windy areas, or wet areas.
Japanese maples do not need a lot of fertilizer. In fact, too much fertilizer stimu-
lates too much growth and makes the tree more ‘leggy’ and weak. Fertilize Japanese maples once a year, in the early spring, with the same type of fertilizer that you use for rhododendrons, azaleas or other acid-loving plants. A monthly application of a soluble, acid-type fertilizer, from May through August, will also help keep the roots growing strong. Do not apply any liquid fertilizers directly to the leaves, it will burn them. Japanese maples flourish in the same growing conditions as Rhododendrons and Azaleas.
Water
Japanese maples do not have any particular, or special water requirements, other than consistency. They can survive on limited water or with plentiful water, just as long as it is applied consis- tently. Do not give the trees a lot of water for a while and then drastically reduce the amount of water. The trees may struggle and the leaves may either dry up or burn. The opposite is also true, do not give the trees limited water and then dramatically increase the water. You may stimulate unwanted growth at the wrong time of year.
Water Japanese maples regularly, especially during the hot, windy weather of July and August. Do not sprinkle the leaves, or the water may actually burn the leaves instead of helping to prevent summer leaf scorch. Proper water management is one key to successful results when growing Japanese maples.
Placement
Most Japanese Maples prefer morning sun with some light afternoon shade. However, Jap- anese maples can grow almost anywhere in the yard. They will tolerate full sun, partial sun, or a lot of shade. The longer the tree has been planted in the yard, the more stress the plant can tolerate. A newly planted Japanese maple may struggle the first summer or two in the full sun. As the roots become established in good soil conditions, and the tree is watered and fertilized properly, the tree will grow just fine in most any area of your yard, including the hot, sunny areas. Green-leaf Japanese Maples tolerate the hot, sunny areas the best but many of the ‘larger-leaf’, red-leaf Japanese Maples will also tolerate the sun. The smaller laceleaf Japanese Maples will struggle in the hottest areas of the yard.
One factor to consider when you place your red Japanese maple is that they do need a little sunlight to maintain their brightest-red color. Too much shade minimizes the red shades. The leaves will not be as striking in the shade as they would be if the tree was planted in another area with more sunlight. Leaves tend to be greenish-red or a bronze color in the shade.
Wind
Japanese maple trees hate hot, dry winds. South winds are the worst. There is not much you can do to prevent damage from these south winds during July and August so keep your tree as healthy as possible. The best prevention for this leaf scorch is to water your trees during, or immediately following, a hot wind. This extra water may help minimize any leaf damage. Remember to keep the water off the leaves during these hot, windy periods.
Temperature
Japanese Maples are very hardy. They can tolerate most winter temperatures when they are healthy. Most Japanese maples that die during the winter either die from root rot, or from the soil drying out too much during the late-fall or winter. Root rot is a soil disease that usually starts by keeping the soil too wet, for too long of a time period during the spring and summer. Many gardeners kill their Japanese maples with kindness.
More Japanese maples die from the hot-dry summer weather conditions than die from the cold winter weather. One factor to remember is that it can be 15 to 25 degrees hotter right next to a house than it is out in the middle of the lawn or garden. This temperature variation can be just enough of a factor that the tree will not survive in that sunny condition, right next to the house, but it will grow just fine in a sunny area out in the yard. The same is true for trees planted next to white vinyl fences.
Pruning
Prune Japanese Maples as little as possible. Do major prun- ing just before the leaves emerge in the spring. Japanese Maples do not respond well to major pruning. They do not send out new leaves or branches on the old wood. Be sure that you make all major pruning cuts just above another side branch that already has plenty of smaller twigs.
Minor corrective pruning and shaping can be done all sum- mer. The only regularly pruning that might need attention is to remove any excessive ‘twiggy’ growth that makes the tree too dense, especially when it is young.
Pest Problems
Japanese Maples are relatively trouble free. The biggest dis- ease problem is from the root rot diseases; pythium, verticillium or fusarium. Keeping your tree healthy is the best way to prevent root rot. Adding sulfur to the soil each spring also helps prevent many root diseases from becoming a problem. Keep your soil consistently moist and not constantly wet.
Aphids, spider mites, and beetle or moth larvae can be an occasional pest that may need to be controlled once in awhile. If all plants had as few pests as the Japanese Maples, gardening would be much simpler.
Container Gardening
In many areas Japanese Maples are used extensively in containers on the porch or patio. In our climate they do not survive without some major winter protection. Many Japanese maple roots die if the soil temperature drops below 14 degrees F. If you can protect your Japa- nese maple, in its container, from getting below 14 degrees F., you can usually have Japanese maple trees grow and flourish in pots on your patio. You may have to move the pots into an unheated shed, put them next to the house, bury them in straw, or make a structure to hold straw around them during the winter. This straw may help to keep them above the critical temperature.
Another important part of winter protection is water. Do not let the container completely dry out during the winter months. Water it when it starts to dry out. The best way to water plants during the winter is with snow. As the snow melts just give the container another shovelful of it
Varieties
Listed below are just some of the many varieties of Japanese maples that are cur- rently available. Not all of these varieties are
available all season long. Some varieties are not even available every year. Some of the more exotic varieties are scarce or in such high demand that their availability is limited from year to year. Sometimes we cannot even order any a year in advance.
The height and width measurements for each variety may vary tremendously. Water, fertilizer, soil, weather conditions, physical injury, and soil pH all influence how fast or slow a tree grows and to what ultimate height the tree reaches.
Acer palmatum
Height 25′ Width 20′ The common ‘green-leaf’ Japanese maple is one of the hardiest varieties. It grows relatively fast and can tolerate a wide range of soil conditions and climatic variations. It is a vase-like tree. It can have single or multiple stems and it becomes rounded with age. The leaves turn yellow to red in the fall
Acer palmatum ‘Aka shigatatsu sawa’
Height 6′ Width 4′ A small tree with intricately patterned leaves which are especially attractive as they unfurl in spring. The leaves are deeply lobed with the margins being sharply toothed. It has light yellow, or yellow-green, leaves with dark green veins. It also has a pink to red blush.
Acer palmatum ‘Beni schichihenge’
Height 9′ Width 8′ The strongly variegated leaves of this cultivar are similar to ‘Kagiri nishiki’ and ‘Butterfly’. The green leaves have a pink-orange-with-white margin. This delicate-look- ing, small tree can be planted where it is admired up close, such as next to a house or in a Japanese Garden. The edges can sunburn during hot, dry, sunny, or windy conditions.
Acer palmatum ‘Bloodgood’
Height 15′ Width 12′ This is one of the most popular Japanese maples and deservedly so. This robust, upright tree has large, deep-red leaves which mature to a deep, rich-purple. It retains its color well, even during the heat of summer. The scarlet winged seeds are an extra bonus with this strong-growing garden standby. Its fall leaf color is crimson.
Acer palmatum ‘Burgundy Lace’
Height 10′ Width 8′ When you need a delicate red maple, consider ‘Burgundy Lace’. This small, low-branched, spreading tree has a generous canopy of burgundy-red, deeply-divided leaves with serrated edges. Its fall leaf color is red. It will sunburn in full sun or with hot winds.
Acer palmatum ‘Butterfly’
Height 6′ Width 3′-5′ This small, dainty, upright, vase- shaped tree has small, variegated blue-green-and-white leaves that are lightly tinged with pink. A good tree to consider for an elegant entry planting. In the fall, the white and cream margins become a blazing magenta. It grows best in partial sun or light shade.
Acer palmatum ‘Emperor I’
Height 12′ Width 8′ This extraordinary cultivar is sure to become the new standard upright Japanese red maple. The leaves have a typical palmatum shape and are a beautiful deep red with a transparent quality that gives them the appearance of stained glass with sunlight streaming through. It is a strong, vigorous grower with upright branching, developing a broad shape with age. The leaves hold their color well during the summer heat.
Acer palmatum ‘Fireglow’
Height 12′ Width 8′ Of the red, upright Japanese maples, this cultivar stands out for its cherry-red foliage which holds well throughout the summer. A refreshing alternative to the dark purple foliage of most ‘red’ upright palmatums.
Acer palmatum ‘Hogyoku’
Height 10′ Width 6′ This is the upright tree with all the typical ‘palmatum’ habits, leaf shape and color. The new growth is often thick and stubby, adding to the unusual appearance of this variety. During the summer the leaves are star-shaped, shiny, and dark green. The fall leaf color is dark, pumpkin-orange instead of the traditional yellow-orange leaf color.
Acer palmatum ‘Kagiri nishiki’
Height 9′ Width 5′ This upright, vase-shaped tree has small green leaves with pink and white variegated margins. The pink and white margins sunburn in hot areas, even in the shade. The leaves turn maroon in the fall. The habit is more open and arching, compared to the stiffly upright, twiggy ‘Butterfly’. The leaves are not uniform in shape so you can have a very interesting leaf pattern on a single tree.
Acer palmatum ‘Karasugawa’
Height 6′ Width 3′ You won’t believe it until you see for yourself. Dramatic, variegated leaves, light-pink new growth, with older leaves mottled white and pink. Some older leaves will have specks of green in them. The stems are also pink and cream streaked. Although somewhat tender, this is a most worthwhile plant. Put this tree in the most protected area of your yard; both from heat and cold.
Acer palmatum ‘Katsura’
Height 3′-4′ Width 2′-3′ It is one of the first Japanese maples to leaf out. The small, five-lobed leaves of ‘Katsura’ are brilliant yellow-orange, turning to a rich green. Fall colors are pastel tones of yellow and orange. This is a small upright dwarf tree. This tree does not like hot, sunny areas.
Acer palmatum ‘Linearilobum’
Height 12′ Width 10′ This green maple has narrow, deep- ly-lobed, green leaves presenting a light and airy appearance reminiscent of bamboo. There are many cultivars but they all have this very unusual appearance. They do not like hot, dry winds but they grow well in semi-protected areas of the yard.
Acer palmatum ‘Moonfire’
Height 12′-15′ Width 10′ This variety has purple-red, almost black-red leaves in the spring. The leaves hold their color well during the summer. The leaves turn crimson in the fall. It is a fast growing tree when young but it slows down with age.
Acer palmatum ‘Nigrum’
Height 12′ Width 10′ It has very dark, purple-red leaves which can turn black-red in some soil conditions. The leaves have a white pubescence as they unfold. The leaf color turns bronze-red in summer and then crimson-red in the fall. The tree grows fast when young but slows considerably with age.
Acer palmatum ‘Nuresagi’
Height 15′ Width 10′ A deep purple-red, upright selection. The leaves are similar in color, shape and size to the well known ‘Bloodgood’ but are held on the tree in such a way as to impart a more refined, airier canopy compared with the dense, heavy canopy of ‘Bloodgood’.
Acer palmatum ‘Okushimo’
Height 20′ Width 20′ Rich-green leaves turn golden-yel- low in the fall. The fall color is one of its most striking charac- teristics. It has a stiff upright vase-like appearance rather than the traditional umbrella-like shape of most Japanese maples. It grows fast when young and can become a large tree fairly quickly. It can tolerate pruning to keep the tree much smaller.
Acer palmatum ‘Omuryama’
Height 9′-15′ Width 12′-15′ This is a tree worth consider- ing. The new leaves emerge with a bright orange cast. They soon turn brilliant green for the summer. The fall color varies from golden-orange and crimson combinations. The outer branches cascade downward. It is not a weeping tree, it just has a fun cascading effect because the branches start upward and then hang down with age.
Acer palmatum ‘Oshio beni’
Height 20′ Width 15′ This medium-sized upright tree has bright orange-red, broad, seven-lobed leaves that turn bright scarlet in the fall. The leaves do not hold their color well in the summer. They turn bronze-green in the heat and will sunburn easily in the hot areas. Consider this lovely cultivar when you need a red maple for fine form and color in a partially shaded area.
Acer palmatum ‘Red Pygmy’
Height 3′ Width 3′ This cultivar has a broad growth habit; it may get as wide as it gets tall. It has maroon-red leaves which are exceptionally narrow. It will often produce large, palmate-type leaves on new wood. Don’t be alarmed, these branches will produce the normal, smaller leaves the following year. Many gardeners think the tree is reverting to another variety but it is just one of the distinctive characteristic traits of this tree.
Acer palmatum ‘Sango kaku’
Height 20′ Width 15′ Widely known as the ‘Coral Bark’ maple, this cultivar is popular due to its flaming, coral-red bark. New branches are green until the first winter when they turn the coral-red. The soft, green leaves are a sharp contrast to the bril- liant coral bark. In the winter the coral stems increase in intensity and stand out against the white drifts of snow. Watch for bright, golden fall leaf color for another surprise effect.
Acer palmatum ‘Shaina’
Height 4′-6′ Width 4′ This cultivar originated as a witch’s broom on a ‘Bloodgood’ maple. It has dark-red leaves with the center leaf lobe shorter and rounded. It has relatively large leaves for such a dwarf maple. The leaves are very closely arranged to give the tree a unique, dense, layered look.
Acer palmatum ‘Sharp’s Pygmy’
Height 4′-6′ Width 4′ This is an outstanding miniature maple; a seedling selection from Sharp Nursery in Oregon. It has small, regular palmatum leaves on a compact, densely branched, rounded shrub turning a deep red in fall. It is one of the most attractive dwarf maples and it is useful in a variety of landscape situations.
Acer palmatum ‘Sherwood Flame’
Height 12′ Width 10′ A vigorous, small tree with deeply divided leaves. One of the best for retaining strong rich-red color throughout the season. A selection discovered in Sherwood, Oregon, which is becoming increasingly popular.
Acer palmatum ‘Shirasawanum Aureum’
Height 15′ Width 10′ A very hard tree to find because it is difficult to propagate and it is extremely popular among the avid Japanese Maple enthusiasts. The spring leaf color is pale-yellow that turns green during the summer. It will retain its yellow color longer in a shady area than it will in the sun. The leaves sunburn easily in the hot sunny areas of the yard. It has a spectacular fall color varying from orange through red and occasionally purple. These colors may vary even on the same leaf. The seeds are bright red that contrast with the yellow leaves.
Acer palmatum ‘Shishigashira’
Height 6′-9′ Width 4′-5′ The “Lion’s Head” maple. Once seen, you’ll always remember this maple! Its distinctive, up- right branches are thickly covered with small, heavy textured, deep green, crinkled leaves that are layered densely on out- ward-spreading branches. Fall color is a brilliant golden-orange. It does not turn colors until very late in the fall, extending your garden’s color display. A true garden aristocrat. It has been cul- tivated for more than 100 years around the world.
Acer palmatum ‘Tobiosho’
Height 20′ Width 20′ A special garden tree. This upright tree has all the typical ‘palmatum’ habits, leaf shape and color. The fall color is it’s main attribute. It has an unmatched electric-scarlet leaf color that will electrify your yard every fall.
Acer palmatum ‘Trompenburg’
Height 15′-20′ Width 15′ A selection made at the Trompen- burg Arboretum, Rotterdam, Holland. This vigorous tree has shiny, deep purple-red leaves. The leaf holds its color well in the summer but will turn bronze-green by fall. The leaf edges roll down giving a most extraordinary, finger-like effect. It has a brilliant crimson-red fall color.
Acer palmatum ‘Tsukushigata’
Height 6′-8′ Width 3′-5′ This tree will attract attention in any garden. The rich, purple-red to black-red leaves are spec- tacular. The leaf color holds well in the summer. However, the shaded side of the leaves tend to show a green cast and the veins become noticeably green. It produces a chartreuse seed that tends to sparkle among the dark foliage. It is a fairly rare variety and it is often hard to find.
Acer palmatum ‘Tsuma gaki’
Height 4′-5′ Width 4′ Yellow-green leaves tipped with red. A small tree which is a pleasing sight in spring with its soft-colored leaves delicately drooping. The leaves tend to droop when they first emerge causing many gardeners to worry that the tree is unhealthy. The leaves stiffen and turn brilliant green in the summer. The leaves turn crimson or red in the fall. This tree sunburns easily in the sun.
Acer palmatum ‘Willow Leaf’
Height 20′ Width 20′ ‘Willow Leaf’ has long, narrow, lobed leaves in a strong, lasting, red-orange color. The finger-like leaves give this sturdy, upright tree an airy, elegant texture. This is one of the lineari- lobium varieties.
Laceleaf Japanese Maple Varieties
Acer palmatum dissectum ‘Crimson Queen’
Height 4′-7′ Width 3′-6′ One of the finest deep-red, laceleaf selections. It retains its color well during the summer on finely dissecting foliage. A dense, broad, mounding plant. It will tolerate the full sun gardens but it sunburns easily during hot, windy weather, especially if the soil conditions are not optimal. This tree will hold its color longer in a partial shaded area than it will in the hot sunny areas. You can increase it’s height by staking branches to grow upright instead of weeping.
Acer palmatum dissectum ‘Ever Red’
Height 4′-10′ Width 3′-12′ A popular, “older” red-leafed laceleaf maple whose merits will continue to make it a sought-af- ter garden plant. Very finely-dissected leaves which emerge in spring with the new shoots and are covered with fine, silvery hairs. A delicate, yet sturdy laceleaf. This tree will hold its color longer in a partial shaded area than it will in the hot sunny areas. This tree will only grow tall if you stake the branches upright, otherwise the branches tend to weep. This tree will sunburn in hot, sunny, and windy conditions, especially if the soil is not acidic.
Acer palmatum dissectum ‘Garnet’
Height 9′ Width 10′ A vigorous, spreading plant covered with large, broadly-dissected, garnet-colored leaves. The habit of ‘Garnet’ is more upright than the typical, mounding laceleaf types. It has the same sun and soil requirements as the other laceleaf maples.
Acer palmatum dissectum ‘Red Dragon’
Height 4′-6′ Width 3′-6′ An exciting new introduction from New Zealand introduced to the U.S. in 1990. This laceleaf selection has it all, and should become the nursery standard of the future. It has dark-purple-maroon foliage throughout the hot summer months. It is a vigorous and well branched tree. It has the same sun and soil requirements as the other laceleaf maples.
Acer palmatum dissectum ‘Inaba shidare’
Height 4′-6′ Width 3′-6′ It is one of the most vigorous laceleaf varieties. It has been cultivated since the 1800’s. It has larger leaves than many other varieties and has a purple-red color that holds well through the summer. The fall color is bright red. It grows in the familiar dense, cascading shape which one associates with the ‘red laceleaf.’ A distinctive tree even in the winter, as bare branches reveal a silhouette of great character. It has the same sun and soil requirements as the other laceleaf maples.
Acer palmatum dissectum ‘Seiryu’
Height 10′ Width 8′ A green-leafed ‘dissectum’ that is an upright grower instead of the traditional weeping form. It is a strong-growing tree, yet the green, dissected leaves give it a delicate appearance. Fall color is a wonderful display of strong- gold, light-yellow, and crimson leaves. It can sunburn easily if it is too hot or windy.
Acer palmatum dissectum ‘Viridis’
Height 4′-6′ Width 3′-6′ This variety grows in a cascading mound form. You can make the tree grow taller if you stake the branches upright. ‘Viridis’ has bright-green, dissected leaves that turn golden-yellow and red in the fall. This is the ‘green-leaf’ variety of the weeping Japanese maple. It has the same sun and soil requirements as the other red laceleaf maples.