Japanese maples, trees for all seasons

By Lynette L. Walther | Jan 12, 2018
Photo by: Lynette L. Walther The new Japanese maple cultivar, North Wind, is ultra-cold-hardy down to Zone 4 and -30. But don’t let its tough exterior fool you; this is a true Japanese maple with finely cut foliage and stunning form and color, spring, summer and fall.

A few years back, I attended a garden writers' conference in Portland, Ore., where I discovered Japanese maples. It isn’t that I was not already familiar with these distinctive little trees. But the sheer numbers of Japanese maples that I saw there, and their extensive uses made me think that Portland must surely be the center of the Japanese maple universe — outside of Japan, of course.

They were everywhere and they were gorgeous. Never had I seen so many of these unique trees in so many applications and situations. Japanese maples (Acer palmatum) are represented by more than 300 cultivars with varying leaf shapes and colorations. Dwarf, small and medium-sized trees, Japanese maples are often used as specimen trees in a landscape due to their spectacular, finely-cut leaves and foliage colors, as well as their Bonzai-like growth forms.

Crabby comment of the day:

I shouldn’t have to tell you this, but if you are using rock (or any other type) salt to de-ice your walkways, steps or drive — stop that right now! Not only are you risking damage to stone and other paved surfaces, you are going to kill grass or any other growing thing that comes in contact with salt. And salt loses its effectiveness at about 15 degrees F. Use sand instead. Sand will help provide traction, and come spring can be swept or raked and spread into the lawn or ornamental beds. In most cases, plain sand is actually good to add to local soils. It helps to loosen up heavy clay soils, improves drainage and will benefit your landscape. Keep a galvanized can covered with a lid and filled with sand near the door. Scatter as needed.

Leaf colors range from brilliant reds and pinks to variegations of green, pink, gold, yellow, red, orange, purple and bronze. And leaf shapes go to the extreme, some with almost “snowflake” complexity.

Most Japanese maples are rated for growing in Zones 5 to 8 with a few heat-hardy to Zone 9, and a few that are cold-hardy to Zone 4. One series of ultra-cold-hardy Japanese maples is the Jack Frost series cold-tested to Zone 4 and -30 F.

From Iseli Nursery in Boring, Ore., “Jack Frost maples are an exciting new line of small to medium-sized landscape trees that were hybridized over the last 20-plus years using Acer pseudosieboldianum as the foundation for hardiness combined with the beauty in leaf and branching of Acer palmatum. They have been evaluated and selected to tolerate the dramatic weather shifts in the upper Midwest of North America. Jack Frost maples bring a new level of durability to a popular group of landscape trees.

“North Wind in the Jack Frost series has been unscathed in field testing, surviving temperatures of -30 F. The palmate leaves emerge red it the spring, changing to green by midsummer. Showy pink samaras standout against the three summer folate. When other fall color has faded in northern landscapes, North Wind continues the show with dramatic tones of orange and scarlet. 20 feet high by 15 feet wide, with broad, upright growth form.”

According to J.D. Vertrees’ “Pocket Guide to Japanese Maples," these colorful trees are easy to plant, because they often have a relatively shallow root system. Given that, regular irrigation is often required when establishing a newly planted tree, and regular watering helps to maintain their unique root systems, whicht lack a deep taproot. This enables Japanese maples to be established where other trees might not survive when there is a hard stratum or ledge beneath the surface, making them good candidates for rock gardens and other landscape uses as well, with these maples preferring a lightly acid soil with good drainage.

Japanese maples do not tolerate saturated or soggy soil locations, nor excessive fertilizing. A rose-type fertilizer or slow-release nutrients applied in early spring should be adequate, according to Vertrees’ guide. The green-leaved varieties do well in full-sun situations, and those with variegated, dark red or other dark-colored foliage prefer some sun protection. All appreciate protection from hot afternoon sunshine, and this, along with mature tree size, should be considered when situating Japanese maples in the landscape.

Whether used as a specimen tree or combined with other Japanese maples, these unique trees add drama, color, texture and interest to almost any landscape all year long.

A topiary cedar stands in stark contrast to a feathery Japanese maple, at the Iseli Nursery’s gardens in Boring, Ore., outside of Portland. (Photo by: Lynette L. Walther)
Comments (2)
Posted by: Lynette Walther | Jan 19, 2018 13:42

You make an excellent point, George Terrien, and one that merits investigation.Your point is well taken, and something that I certainly will consider in future columns. Currently Japanese maples are listed as "moderately" invasive in states south of Maine, especially in mid-Atlantic states such as Virginia. However the Japanese maple is not on Maine's list of invasive plants. Thank you for your thoughtful comment.

Posted by: George Terrien | Jan 15, 2018 13:17

How well do Japanese Maples support Maine's pollinators?  Do they harbor any threat to our ecology, whether parasitic or simply competitive?  Please, editors, when you publish articles like this one, insist that the author educate us on whether selecting what is being promoted will have significant effect on our surroundings, positive or negative, incidental or profound.  At least, take the advantage of the opportunity to sensitize us to the environmental effect of what we think might to be purely aesthetic or economic.

If you wish to comment, please login.