Tree of the Season: Japanese maple

Japanese maples have an elegance and sculptural quality that resembles dance. Careful study of their form, in any season, can call the viewer back to the natural world. In winter, the falling leaves raise the curtain on the form of the trunks, and put the dance on center stage. Winter rain intensifies the show by adding a sensuality to the movement of stem and bough, one that beckons to even the unpracticed eye. In spring, certain varieties of Japanese maples send out new leaves so bright a green they appear lit from within. In summer, upright cultivars that are well pruned have spaces between the branches, giving the canopy the appearance of being composed of many floating islands. And in fall, Japanese maples mark the change of season by turning colors ranging from yellow to scarlet, depending on the variety of maple; there are many varieties. 

Luckily, Japanese maples are relatively easy to grow, and relatively tough. In their long evolutionary dance–fossilized maple leaves date back over 60 million years–Japanese maples have developed the genetic information necessary to protect them against most common garden afflictions. They are, however, subject to verticillium wilt, a soil-borne fungal disease that can cause dieback, and sometimes death. There is no known cure for verticillium, but you can decrease the likelihood of your new maple getting the disease if you 1) don’t plant it in ground known to have verticillium, 2) make sure the soil around the tree is well drained so that the roots don’t remain soggy throughout the winter, and 3) protect the tree against environmental stresses by giving it summer water and keeping it well mulched. Maples can grow and remain healthy in gardens with a history of verticillium. If they are not stressed by soils too damp, too dry, or too compacted, some individual maples can thrive even though a near neighbor may die. It depends on the genetics of the individual. If your mature maple shows significant dieback, it may be fighting a case of verticillium. It is not necessarily a death sentence. Some trees succeed in fighting off the disease. You can help them recover by pruning out the deadwood and improving the soil environment by mulching and aerating.

Though some varieties can withstand full sun, Japanese maples do best in part shade. They do not thrive when exposed to the drying effect of constant wind. If you live on an exposed hillside, it is best to plant them in the lee of a larger tree. Dieback in Japanese maple crowns often is the result of too much sun, too much wind, or the even more deadly combination of the two. Maples need water. Keeping them moist throughout the summer and fall, and into the early winter in dry years, will make them happier and more disease resistant.

Pruning, besides benefiting the mental health of the pruner, can enhance the grace of the plant. If your pruner is an artist, removing deadwood and teasing apart the plant’s natural layering opens little windows that reveal and accentuate the tree’s natural form. A well-pruned tree looks as if it hasn’t been pruned. Paradoxically, it looks more natural after pruning than before. Though it is sometimes necessary to lower the crown of a maple, as when it is beginning to block a treasured view, lowering should be done only when necessary, and the lowering should not be so drastic as to involve topping cuts (see the article on topping). Lowering a maple to gain a view is not something that you can do just once. Pruning down the crown stimulates new growth, and maintaining the view, or the size reduction, will require yearly pruning. No matter how good the artist, you can’t make a topped maple look as good as a natural tree. Much pruning, and therefore expense, can be avoided by planting the right variety in the right place. When planting a new tree, plant a cultivar that won’t exceed the desired height when it matures. This is almost always preferable to containing a variety that will grow beyond the desired size.

It is our hope at Brende & Lamb that the pleasure our clients derive from their well-pruned trees exceeds the considerable pleasure we get from revealing the beauty inherent in their trees.

If your trees and shrubs need a little TLC - call us to schedule a free estimate.

Blaine Brende & Joe Lamb
510-486-TREE (8733)
bl@brendelamb.com
www.brendelamb.com