Culture Notes
The tree is easily transplanted, grows quickly, is adapted to a wide variety of soils (including alkaline) and has brilliant yellow fall color unmatched by most trees. It can also tolerate coastal conditions. Well adapted to street tree plantings, it is often overused. Norway Maple's dense shade and shallow root system competes with lawn grasses, and the shallow roots can make mowing under the tree difficult. Be certain to locate the tree 4 to 6 feet away from walks and patios to prevent damage to the hard surfaces.
Trunks occasionally crack on the southern side during the winter initiating some trunk decay. This may be due to the trunk receiving an injury several years back. Branches sometimes fail from too much weight toward the end of the branch. The dense canopy causes this situation and it can be aggravated by pruning inappropriately. Minimize this by thinning these branches on a regular basis and removing some of the main branches when the tree is young to allow those that remain to develop secondary branches closer to the trunk. When you thin the plant, be sure to remove some secondary branches toward the ends of the main branches leaving interior secondary branches intact.
Seeds of the species germinate readily in the landscape and could become a nuisance. The species has formed thickets in native woodlands in parts of the US choking out native vegetation. Pollen can cause some allergy problems for some people.
Maintain adequate mulch area
Clear all turf away from beneath the branches and mulch to the drip line, especially on young trees, to reduce competition with turf and weeds. This will allow roots to become well established and keep plants healthier. Prune the tree so trunks and branches will not rub each other. Remove some secondary branches on main branches with included bark. This reduces the likelihood of the main branch splitting from the tree later when it has grown to become an important part of the landscape. Locate the tree properly, taking into account the ultimate size, since the tree looks best if it is not pruned to control size. The tree can enhance any landscape with its delightful spring flush of foliage. It can be the centerpiece of your landscape if properly located.Â
Pests, Diseases and Damaging Agents
Aphids, scales and borers can be found on the Maples. Scorch occurs during periods of high temperatures accompanied by wind. Verticillium wilt can kill plants. Girdling roots often encircle and can cause serious decline in tree health. Asian long-horned beetle, a new pest in certain regions of the country since 1996, attacks and kills trees. Tunneling by beetle larvae girdles tree stems and branches. Potentially resistant trees include Metasequoia (Dawn Redwood), Taxodium (Baldcypress), Corylus colurna (Turkish Hazelnut), Quercus (Oak), Gleditsia (Honeylocust), Tilia (Linden), Ginkgo, and Gymnocladus dioica (Kentucky Coffee Tree).
This genus is sensitive to fluoride air pollution, sources of which include glass and brick manufacturing plants and other facilities that heat or treat with acid materials containing fluoride. Symptoms due to fluoride injury are more prominent on the side of the plant facing the pollution source. In deciduous plants, symptoms include leaf browning along the margins of the leaves. A dark brownish band may appear along the boundary between healthy green tissue and the affected brown tissue. Eventually, the entire leaf may turn brown. In conifers, the tips of the current year's needles turn reddish brown. Older needles are typically unaffected. If you suspect fluoride has injured this plant, look in the neighborhood for gladiolus plants. They serve as indicator plants for fluoride air pollution damage because they are very sensitive to it. Other sensitive plants include ash, maple, oak, white pine, poplar, and redbud. Plants that resist injury include birch, flowering cherry, dogwood, hawthorn, American linden, juniper, pear, spirea and sweet gum.