Growing Japanese Maples in Wisconsin

Japanese Maples are a highly coveted landscape plant for many good reasons. They have a lot going for them, such as distinctive foliage in leaf form and color, interesting shape, overall size, and beautiful fall color. They are sure to inspire awe and are some of the easiest trees to identify.

The term “Japanese Maple” is somewhat of a misleading name; it has two meanings. One is applied in the nursery industry to a group of small ornamental trees. For the serious dendrologist, the second meaning indicates all the species of the genus Acer which are endemic to Japan and portions of neighboring regions. Many species labeled as Japanese Maple may also be native to China, Korea, eastern Mongolia, and even southeast Russia. In the United States, all cultivars of a few species of Acer are grouped into this general term of Japanese Maples. Included are all the cultivars and forms of Acer palmatum; however, we also find listed cultivars of A. japonicum, A. sieboldianum, A. pseudosieboldianum, and in some cases, A. buergerianum and A. crataegifolium.

A. palmatum (like the ‘Bloodgood’ variety shown above) and A. japonicum are at the center of this labeling. The cultivars and variations of these two species have been bred, selected, and propagated for over 400 years by the Japanese resulting in more than 250 cultivars between these two species alone.

During the last 200 years, these cultivars have found their way into horticultural collections, arboreta, and the nursery industry. Today, there are at least a thousand varieties of Japanese Maples. The genus all maples come from, Acer, is known to readily interbreed, crossing with one another easily, which further creates a considerable variation in their form, habit, bark, leaf shape, and color.

Throughout this article, we will use the term “Japanese Maple” when referring to the many different maple species commonly called Japanese Maples, not one species in particular. Japanese Maples thrive best in zones 5-9 but can be successfully grown in colder climates. Check out our article on USDA Hardiness Zones if you would like to understand better what hardiness zones are, how they work, and to see a map.

Despite much of Southeastern Wisconsin being listed as zone 5, our windy winters and late spring frosts make growing Japanese Maples tricky. Wisconsin’s winter winds are often closer to temperatures in zones 4 and sometimes even 3. For this reason, Japanese Maples are considered marginally hardy in Wisconsin. But don’t despair! They can and have thrived here, but only under ideal conditions. You can succeed in growing zone 5 hardy Japanese Maples, but special precautions must be taken to increase the chances of survival and longevity.

Ideal light conditions for a Japanese Maple would be dappled light or part shade. Japanese Maples can grow in full sun but will still need some shade throughout the day as those grown in full sun are prone to leaf scorch, especially in hot and dry locations. Some varieties are less tolerant than others of full sun, such as dissectum Japanese Maples, which are especially prone to leaf scorch. Dissectum Japanese Maples are easy to tell apart from others as the foliage looks like lace from a distance, but up close, you’ll see that the leaves have long, slender “fingers” that are deeply lobed. With foliage much finer than other Japanese Maples, intense sunlight can burn leaves quickly if allowed to dry out.

Japanese Maples need a couple of hours of unfiltered sun, but if the planting location is primarily shady, you will have a much happier plant.

Examples of dissectum Japanese Maples include:

Crimson Queen (Acer palmatum var. dissectum ‘Crimson Queen’)
Red Dragon (Acer palmatum var. dissectum ‘Red Dragon’)
Waterfall (Acer palmatum var. dissectum ‘Waterfall’)
Tamukeyama’ (Acer palmatum var. dissectum ‘Tamukeyama’)

Dissectum maples often have a weeping form but are not exclusively found as such.

Successfully growing Japanese Maples in Wisconsin begins with proper siting. You’ll want to choose a planting location that will naturally give your tree permanent protection from the winter winds. The prevailing wind direction in Wisconsin is from the West. The best spots to plant a Japanese Maple are those on the eastern sides of things like buildings or evergreen hedges. This protects the tree from sweeping western winds and strong sun. In general, Japanese Maples are best grown on the South to Southeast side of your home.

You will also need to apply a generous layer of bark mulch over the tree’s root zone and water it thoroughly throughout the fall before the ground freezes. Your tree will benefit from having more water stored up going into the winter season and will come out of dormancy refreshed and ready to grow.

It is important to keep in mind that you should refrain from using rock or stone mulch as it can harm the health of the Japanese Maple. Rock and stone mulch raises the temperature of the soil, can change the pH level to be more alkaline, and because it doesn’t break down, provides no benefit to the soil in the way that wood mulch does.

In addition to cold temperatures, sunscald and frost cracks are also issues that can impact the health of Japanese Maples.

Sunscald happens during sunny, cold winter days on the south to the southwest side of the tree. When the bark on the tree warms up on sunny days, the dormant cells within the plant become active in response to the sun’s warmth. The activated cells lose some of their cold hardiness and are injured when the temperatures drop during the nighttime. This damage can cause cells to die, leading to the discoloration of the bark. The repeated switch from warm to freezing temperatures causes the inner layers of bark to expand and shrink repeatedly; eventually, this tension causes a frost crack.

Frost cracks themselves likely won’t kill a tree, but they are an open invitation for insects and disease. Younger trees have thin bark, making them more susceptible to this damage. As most trees mature, they develop thicker bark and become less prone to sunscald or frost crack injury.

Fortunately, protecting trees from this kind of damage is easy and inexpensive. Sunscald and frost cracking can be prevented by wrapping the tree trunk with a white or light-colored guard to reflect the sun and will also keep the bark at a more consistent temperature. Don’t use brown paper tree wraps or black-colored guards as they absorb heat from the sun. The best time to put on a guard is in the fall, removing it in the spring after the last frost.

Being mindful of your landscape can help avoid these types of injuries. Consider using any buildings for protection or plant evergreens to the south to southwest of your Japanese Maple for additional shelter. If your tree does suffer a wound from sunscald or frost cracks, don’t panic! Trees have an incredible ability to seal their wounds. Through a process called compartmentalization, trees will cover the wound with tissue and produce new, healthy wood over the once-damaged area. They don’t exactly “heal” the wound but form new healthy tissue over it.

If your property does not have a suitable location for a Japanese Maple, consider an alternative such as other East-Asian Maples hardy to zone 4. For example, Paperbark Maple (Acer griseum), Three-flower Maple (Acer triflorum), Manchurian Striped Maple (Acer tegmentosum) and Korean Maple (Acer pseudosieboldianum) are all wonderful alternatives that are more cold-hardy, and just as beautiful and unique.

As Maples interbreed so readily, there are hybrid Maples bred from crossing Zone 5 Japanese Maples with maples hardy to Zone 4, resulting in a tree hardy to Zone 4 with some of the sought-after ornamental characteristics of Japanese Maples.

Japanese x Korean maple hybrids are perhaps the most commonly seen, such as:

Northern Glow® (Acer pseudosieboldianum x palmatum ‘Hasselkus’), developed by Professor Ed Hasselkus in Madison, Wisconsin
Arctic Jade (Acer x pseudosieboldianum ‘Arctic Jade’)
North Wind (Acer x pseudosieboldianum ‘North Wind’)
Final Fire (Acer x pseudosieboldianum ‘Final Fire’)

Although there are other Japanese Maple hybrids hardy to zone 4, they are far less common than Korean Maple hybrids and include the Gingerbread Maple, which is a cross between Acer griseum, the Paperbark Maple, and Acer maximowiczianum, formally known as Acer nikoense, the Nikko maple

‘Bloodgood’ is one of the most popular cultivars of Acer palmatum, particularly in the northern United States. Its stature, form, and color make it well-suited as an ornamental or accent tree.

Height: 12-20’
Width: 15-20’
Growth Form: Upright, rounded habit. Broader with age
Foliage: Bright red in spring, matures to deep purple
Fall Color: Crimson-red

‘Emperor 1’  is a great choice for those looking for a small-statured specimen. Its form becomes rounded with age but tends to be upright in youth. The foliage emerges later in spring than ‘Bloodgood’ which helps avoid late spring frost damage.

Height: 12-20’
Width: 12-20’
Growth Form: Upright, rounded habit. Broader with age
Foliage: Dark red
Fall Color: Crimson-red

‘Crimson Queen’ is a well-known weeping variety of Japanese maple. It has a short, mounded form, dense with dark red foliage, and features weeping and spreading branches.

Height: 8-10’
Width: 10-12’
Growth Form: Dense, broadly spreading habit with cascading branches
Foliage: Fine-textured, dissected foliage emerges bright red, matures to burgundy
Fall Color: Brilliant bright red

‘Mikawa Yatsubusa’ is a highly unique, dwarf, and compact cultivar. Featuring attractive bark, tight growing foliage, and sculptural branch structure.

Height: 3-5’
Width: 3-5’
Growth Form: Compact Dwarf Multi-branched Sculptural, nearly spherical form
Foliage: Medium green foliage grows closely together, overlapping one another
Fall Color: Brilliant red to burgundy

‘Waterfall’ stands out from other dissectum maples with its green foliage when most are red. It grows with a similar habit to the others, with weeping and spreading branches. Bright red flowers stand out against its first flush of foliage.

Height: 8-12’
Width: 10-12’
Growth Form: Dense, broadly spreading habit with cascading branches
Foliage: Fine-textured, highly dissected deep green foliage
Fall Color: Golden orange to red

‘Tamukeyama’ is yet another iconic red-leafed dissectum maple. What separates this cultivar from the others in its group is its slightly smaller mature stature. This cultivar tends to leaf out slightly later in spring than ‘Crimson Queen’.

Height: 6-10’
Width: 10-12’
Growth Form: A dwarf tree with a mounding, weeping habit and cascading branches
Foliage: Purple-red deeply dissected foliage
Fall Color: Bright red

‘Shishigashira’, also known as “Lion’s Head” is an old variety of Acer palmatum that is somewhat rare today in the nursery world. Its densely packed foliage adds a unique texture to the landscape. A very interesting tree! This cultivar is a favorite in the bonsai trade.

Height: 10’
Width: 7’
Growth Form: Upright to broadly rounded
Foliage: Small, crinkled, deeply lobed green leaves
Fall Color: Golden yellow to crimson

Patience! While fairly vigorous in youth, its growth slows down with age. It has large chartreuse leaves with bright red petioles making this one of the most desired maples.

Height: 8-10’
Width: 8-10’
Growth Form: Dwarf Upright Rounded
Foliage: Large, rounded palmate lime green – chartreuse leaves with 7-9 pointed lobes
Fall Color: Variable Golden yellow, orange-red

Having received an Award of Garden Merit from the Royal Horticultural Society in 1984. It is reputedly hardier than other forms of Acer japonicum. Noted for its delicate foliage and superb fall color.

Height: 10-12’
Width: 15’
Growth Form: Low-branched, rounded form
Foliage: Dark green Deeply cut, fern-like
Fall Color: Scarlet to purple