Grow Japanese maples as ornamentals

When it comes to growing ornamental trees, nearly everyone these days has a dwarf weeping cherry or two somewhere near the house.

Everyone except me, that is.

While I think weeping cherry trees are attractive and I’m not ruling out ever owning one, when I browse a garden center looking for something interesting my attention is always drawn to Japanese maples, particularly the palm-leaf maples and especially the dwarf varieties.

Unlike the weeping cherry, also called Japanese cherry, maples don’t burst into flower in early spring. Instead, the hundreds of varieties of Acer palmatum have leaves of nearly every color making it impossible to miss the flowers. With weeping cherry, the flowers fade and drop and what’s left is an umbrella shaped tree that, while attractive, has already had its most interesting show of the season.

Palm-leaf maples, however, have interesting leaves that can be described like lace or feathers that last all summer until they change color in the fall and continue to put on a show until the leaves fall. And yet even when all that is left by November are bare branches, the interesting shape of their growth is still an attraction in the winter garden.

Depending on the variety, Japanese maples can range from small shrub-like trees to as tall as 25 feet. I prefer dwarf Japanese maples, slow-growing trees that don’t grow taller than 6 feet.

Also depending on the variety, trees can grow upright with spreading branches or they can be umbrella shaped, similar to the weeping cherry. Leaf color can include pale to emerald green, deep burgundy, maroon, bronze, orange, yellow and bright red. Leaves can be very small and have the familiar maple shape or they can be long, narrow and palm-like, as their name implies.

Most of these dwarf trees are grafted onto sturdier rootstock. Many varieties are excellent choices for bonzai enthusiasts as long the graft is low on the trunk and very clean with little sign of a scar.

I once attended a garden conference where a vendor who specialized in dwarf Japanese maples had so many different varieties, it was difficult to choose which I liked the best. I came home with five trees, all different in one way or another.

Here’s the catch. Dwarf Japanese maples need protection from winter winds and some varieties should be planted in containers so they can be moved to a protected area over the winter. Most are hardy to our area, but some won’t be happy if we should have a particularly cold winter for a long period of time.

My sturdiest tree is still protected from winter winds because I purposely planted it as an understory tree near taller conifers. It’s leaves are deep crimson and even after they burst out in spring, I have been known to cover the tree with a sheet or blanket if a late frost is predicted. While a light frost won’t kill the leaves, it can cause them to turn pale and spotty, which is how they remain all summer.

Trees planted in the ground require a planting hole at least two to three times the width of the root ball, but no deeper than they are planted in their container. Be sure to keep the graft above the soil line. Thoroughly soak the root ball while planting and continue to water at least once a week until you start to see new growth, indicating the roots have begun to establish themselves.

Japanese maples, particularly those with colorful leaves, should be planted as understory trees where they can get plenty of bright light, but not the hottest sunlight of the day.

Adding two to three inches of mulch can also help the tree retain moisture, but never put mulch against the trunk of any tree.