Acer saccharinum 'Pyramidale': 'Pyramidale' Silver Maple

Introduction

This cultivar of silver maple has a broad columnar shape with essentially one trunk and is a rapidly growing, fairly weak-wooded tree that reaches a height of about 60 to 70 feet on a moist to wet site. The tree is useful in wet areas, transplants easily, and can grow where few others can. It should be saved for planting in wet areas away from people or where nothing else will thrive. Roots often grow on the surface of the soil, making mowing grass difficult under the canopy. They also are aggressive, growing into septic tank drain fields and into broken or leaky water and sewer pipes. It is also hard to plant shrubs and other plants beneath the branches due to the dense root system.

General Information

Scientific name: Acer saccharinum

Pronunciation: AY-ser sack-uh-RYE-num

Common name(s): 'Pyramidale' silver maple

Family: Aceraceae

USDA hardiness zones: 3A through 9B (Figure 2)

Origin: native to North America

Invasive potential: native cultivar

Uses: urban tolerant; reclamation

Description

Height: 60 to 70 feet

Spread: 25 to 35 feet

Crown uniformity: symmetrical

Crown shape: columnar, pyramidal

Crown density: moderate

Growth rate: fast

Texture: medium

Foliage

Leaf arrangement: opposite/subopposite (Figure 3)

Leaf type: simple

Leaf margin: parted

Leaf shape: star-shaped

Leaf venation: palmate

Leaf type and persistence: deciduous

Leaf blade length: 2 to 4 inches, 4 to 8 inches

Leaf color: green

Fall color: yellow

Fall characteristic: showy

Flower

Flower color: red

Flower characteristics: showy

Fruit

Fruit shape: elongated

Fruit length: 1 to 3 inches

Fruit covering: dry or hard

Fruit color: green, brown

Fruit characteristics: does not attract wildlife; showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; not showy; typically one trunk; thorns

Pruning requirement: needed for strong structure

Breakage: susceptible to breakage

Current year twig color: reddish, brown

Current year twig thickness: thin, medium

Wood specific gravity: 0.47

Culture

Light requirement: full sun, partial sun or partial shade

Soil tolerances: sand; loam; clay; acidic; well-drained; extended flooding

Drought tolerance: high

Aerosol salt tolerance: moderate

Other

Roots: can form large surface roots

Winter interest: no

Outstanding tree: no

Ozone sensitivity: unknown

Verticillium wilt susceptibility: susceptible

Pest resistance: resistant to pests/diseases

Use and Management

Silver maple will grow in areas that have standing water for several weeks at a time. It grows best on acidic soil, which remains moist, but adapts to very dry, alkaline soil. Leaves may scorch in areas with restricted soil space during dry spells in the summer but will tolerate drought if roots can grow unrestricted into a large soil volume.

The bright yellow fall color can attract attention in early fall, but you will pay the price with the abundant number of leaves to rake. To develop a stronger, more durable tree, prune so that major limbs remain smaller than half the diameter of the trunk.

Silver maple can be a prolific seed producer giving rise to many volunteer trees. It often sends up sprouts from the trunk and branches, producing an unkempt appearance. There are numerous insect and disease problems. There are too many other superior trees to warrant wide use of this species, but it does have its place in tough sites away from buildings and people. The species grows extremely fast so creates almost instant shade, making it a popular tree among homeowners throughout its hardiness range. This cultivar shares the fast growth rate.

Trees are susceptible to many pest problems.

There are a few cultivars, but these also have weak wood: 'Silver Queen'—bright green leaves with lower leaf surfaces silvery; 'Skinneri'—somewhat weeping, pyramidal form, dissected leaves with a better branching habit; 'Weiri'—cutleaved form with pendulous branches.

Trees are propagated from seeds and from cuttings.

Pests

Leaf stalk borer and petiole borer cause the same type of injury. Both insects bore into the leaf stalk just below the leaf blade. The leaf stalk shrivels, turns black, and the leaf blade falls off. The leaf drop may appear heavy but serious injury to a healthy tree is rare.

Gall mites stimulate the formation of growths or galls on the leaves. The galls are small but can be so numerous that individual leaves curl up. The most common gall is bladder gall mite found on silver maple. The galls are round and at first green but later turn red, then black, then dry up. Galls of other shapes are seen less frequently on other types of maples. Galls are not serious, so chemical controls are not needed.

Crimson erineum mite is usually found on silver maple and causes the formation of red fuzzy patches on the lower leaf surfaces. The problem is not serious, so control measures are not suggested.

Aphids infest maples, usually Norway maple, and may be numerous at times. High populations can cause leaf drop. Another sign of heavy aphid infestation is honey dew on lower leaves and objects beneath the tree. Aphids are controlled by spraying or they may be left alone. If not sprayed, predatory insects will bring the aphid population under control.

Scales are an occasional problem on maples. Perhaps the most common is cottony maple scale. The insect forms a cottony mass on the lower sides of branches. Scales are usually controlled with horticultural oil sprays. Scales may also be controlled with well-timed sprays to kill the crawlers.

If borers become a problem, it is an indication the tree is not growing well. Controlling borers involves keeping trees healthy. Chemical controls of existing infestations are more difficult. Proper control involves identification of the borer infesting the tree then applying insecticides at the proper time.

Diseases

Verticillium wilt symptoms are wilting and death of branches. Infected sapwood will be stained a dark or olive green, but staining can't always be found. If staining cannot be found, do not assume the problem is not verticillium wilt. Severely infected trees probably cannot be saved. Lightly infected trees showing only a few wilted branches may be pulled through. Fertilize and prune lightly infected trees. This treatment will not cure the problem but may allow the tree to outgrow the infection. Girdling roots will cause symptoms that mimic verticillium wilt.

Scorch occurs during periods of high temperatures accompanied by wind. Trees with diseased or inadequate root systems will also show scorching. When trees do not get enough water, they scorch. Scorch symptoms are light brown or tan dead areas between leaf veins. The symptoms are on all parts of the tree or only on the side exposed to sun and wind. Scorching due to dry soil may be overcome by watering. If scorching is due to an inadequate or diseased root system, watering will have no effect.

Tar spot and a variety of leaf spots cause some concern among homeowners but are rarely serious enough for control.