Japanese maples

Flower & Garden Magazine, Dec, 1996 by Pam Waterman

Most Japanese maples -- upright? medium growers as well as dissectums -- are grafted onto seedling rootstocks for several reasons. Not all cultivars grow well on their own roots? but will perform with a strong root system in place. Some cultivars are notoriously difficult to root and would be in constant short supply if they were propagated only by cuttings. And although the seedling offspring of Japanese maples show considerable variation? grafting reproduces the desirable characteristics of the most popular cultivars.

Because of its slow growth and labor-intensive care before and after grafting? a large specimen of a dissectum such as 'Tamukeyama' may be the most expensive garden purchase you make in a year. But like a fine piece of art or furniture, it won't take long to recoup your investment from this cascading maple in the pleasure it brings. Plants that have been grown from seed? and therefore don't carry a cultivar "name?" still make excellent trees for the landscape and are less expensive than grafted cultivars. Seedlings of both red- and green-leafed varieties of maple are often sold in nurseries marked simply as Acer palmatum atropurpureum or A. palmatum.

Conditions suiting azaleas and camellias -- well-drained, slightly acid soil enriched with organic matter -- also suit Japanese maples. They can be grown in sun or partial shade, but the red varieties won't achieve brilliant color in heavy shade. Too much midday sun, especially in the warmer, drier areas of the country, results in leaf burn on some delicate cultivars, such as golden fullmoon maple (A. japonicum 'Aureum'). Filtered sun conditions appropriate for an understory tree satisfy a wide group of maples.

Both A. palmacum and A. japonicum are hardy to Zone 6, but certain cultivars can be grown in Zone 5 in protected sites. Where the soil freezes, a winter mulch provides extra protection for the roots.

Most gardeners find Japanese maples easy to grow. The occasional aphid attack in spring can be treated in the same manner as roses are treated. Spider mites may appear on maples located in areas with poor air circulation. Hosing off the plants daily may mitigate the problem. Chemical controls are also available.

A certain amount of natural grooming will cause isolated maple twigs to die. When more than an occasional twig is affected, the problem may be caused by one of the diseases that strike maples, usually as the result of poor drainage, excessive water or insufficient air circulation. Avoid these problems with proper planting and culture.

Occasionally maple breeders become overstocked with particular plants. That's when the bargain-hungry gardener needs to shop. A year ago I found grafted plants in gallon containers on sale for $5.98 at a local discount nursery. I snapped up five of the dozen or so maples available. Depending on the varieties, one-gallon cultivars usually retail between $15 and $30. With my five-tree "forest" of potted maples, I can experiment with pruning and even take the chance of planting one on a difficult hillside.