Tree · Sapindaceae
Silver Maple
Acer saccharinum
Fast, tough, and happy with wet feet, the silver maple throws up shade quicker than almost any other tree.
Full sun
Every 7–14 days
USDA 3–9
50–80 ft · 15.2–24.4 m
Overview
Silver maple earns its name from the pale, silvery undersides of its deeply cut leaves, which flash and shimmer the moment a breeze turns them over. It's a large native tree of riverbanks and floodplains, and you'll often hear it called river, swamp, or water maple for the wet ground it loves. Few shade trees grow as fast.
That speed is the trade-off. The wood comes in weak and brittle, so limbs tend to crack in ice and high wind, and the greedy surface roots buckle sidewalks, clog drains, and push into sewer lines. Give it room far from the house, the driveway, and the utilities, and most of that trouble stays out of your way.
Where it shines is on a big, open, damp site that defeats fussier trees. It shrugs off wet soil, cold winters, and some drought once it's settled in, casts deep shade in a hurry, and flowers in late winter before almost anything else has woken up. Plant it for what it does well and site it with care, and it's one of the easiest trees you can grow.
Care
The short version: full sun and moist to wet, slightly acidic soil suit it best, it asks for almost no feeding, and the one real job is structural pruning while the tree is young so the brittle wood holds up to storms.
Light
Plant in full sun for the strongest, fullest tree, though it takes partial shade without much complaint. The more sun it gets, the denser the canopy and the better the form.
Water
This is a floodplain tree at heart, so it's right at home in moist to wet ground and even tolerates poorly drained spots. Water young trees regularly until they're established, after which they handle some drought on their own.
Soil
Silver maple is very adaptable about soil, taking everything from average to wet and from well-drained to soggy. It does best on the slightly acidic side, a pH of 5.5 to 7.0, and alkaline ground tends to bring on yellow, chlorotic leaves.
Temperature
It's a cold-tough tree, riding out winters down to -29°F (-34°C) and summers up to 100°F (38°C). That range is what makes it plantable across so much of the country.
Humidity
Ordinary outdoor air suits it fine, so there's no humidity figure to manage. The tree's needs are met by the soil moisture far more than by the air around it.
Feeding
A silver maple rarely needs feeding, and a soil test should come first. Use a balanced slow-release tree fertilizer in early spring only if the soil shows a deficiency, and on alkaline ground treat chlorosis with iron or manganese instead.
Pruning
Pruning is the one job that really matters here. Work in summer or while the tree is dormant, cutting out dead, weak, crossing, or co-dominant stems and any included bark, and shape young trees early so the brittle wood is far less likely to break in a storm.
Repotting
This is a landscape tree, so repotting rarely comes up. If you're holding a young one in a nursery container, move it on before the roots start circling or pushing out the drainage holes.
Size & spacing
Give it serious room. A mature silver maple reaches 50 to 80 feet (15 to 24 m) tall and spreads 35 to 70 feet (11 to 21 m) wide, so set it far from buildings, walks, and pipes the roots could reach.
When to plant
Silver maple is hardy across zones 3 to 9 and goes in the ground in either spring or fall, while the tree is dormant or just stirring. Its flowers open early, from February to April, well before the leaves unfold. Plant it young so it can settle its roots before the first hard season.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring or fall
- Harvest: February to April (flowers before leaves)
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
Most silver maple trouble traces back to its fast, brittle growth or to soil that doesn't suit it. Catch the early signs on the limbs and leaves and you can head off the worst of it. Match what you see below, then act while it still helps.
Limbs that crack and tear off in storms
Silver maple grows fast, and that speed leaves the wood weak and brittle. Tight V-shaped crotches with bark pinched inside split open under ice, snow, or a hard wind. Prune young trees to one strong leader with wide branch angles, take off any cracked or hanging limbs right away, and bring in a certified arborist for the big ones overhead.
Fix:
- Remove broken and hanging limbs promptly
- Make clean cuts back to the branch collar
- Have large or hazardous limbs assessed by a certified arborist
Branches that wilt and die back
Sudden wilting on one side, often with olive streaks in the sapwood, points to verticillium wilt, a soil fungus that clogs the tree from within. In a cool, wet spring anthracnose can also blotch the leaves along their veins. There's no spray that cures wilt, so prune dead wood well below the symptoms, keep the tree watered and vigorous, and don't replant a susceptible species where wilt has struck before.
Fix:
- Prune out dead wood well below symptoms
- Water during drought and maintain tree vigor
- Do not replant susceptible species in known Verticillium sites
Yellow leaves with veins that stay green
This is chlorosis, and it shows up when the soil runs alkaline and the tree can't pull up enough manganese or iron. The new leaves go pale and washed out while the veins hold their color. Test the soil pH, lower it where you can, work in chelated iron or manganese, and keep lime away from the root zone.
Fix:
- Test and lower soil pH where feasible
- Apply chelated manganese or iron amendments
- Mulch and avoid lime near the root zone
White cottony fluff on the branches with sticky leaves below
Those cottony lumps on the undersides of the branches are the egg sacs of cottony maple scale, and the sticky honeydew they drip turns into black sooty mold underneath. The damage is mostly cosmetic on a healthy tree. Watch the branches through late spring and early summer, treat the crawlers with horticultural oil, and leave the predator insects alone to do their part.
Fix:
- Apply horticultural oil during dormancy
- Spot-treat crawlers with horticultural oil
- Conserve natural predators and parasitoids
Toxicity
Good news for most households: silver maple, like the rest of the maples, is non-toxic to cats and dogs and harmless to people, who have long tapped it for syrup. The one real exception is horses. Wilted or dried maple leaves can damage a horse's red blood cells, so keep fallen and storm-broken foliage well away from any paddock.
Toxic to
Horses
Safe for
People · Cats · Dogs · Rabbits · Livestock · Birds
Horses Caution
Fresh leaves on the tree are fine, but wilted or dried leaves are the real hazard. After eating them a horse may turn dull and weak, go off its feed, and pass dark red to brown urine as its red blood cells break down. Rake up storm-downed branches and fallen leaves before they reach a paddock, and call a vet at once if a horse has gotten into them.
Cats Safe
Maples are on the ASPCA non-toxic list, so a cat that nibbles a leaf has nothing to fear here.
Dogs Safe
A dog can chew the foliage or carry a fallen twig around the yard without any poisoning risk.
Rabbits Safe
Silver maple poses no toxicity problem for rabbits.
Livestock Safe
Cattle, goats, and sheep can graze near a silver maple without trouble, though the wilted-leaf risk that hits horses is worth keeping in mind for grazing animals.
Birds Safe
Birds nest in the canopy and feed on the seeds with no ill effect.
People Safe
The tree isn't poisonous to people, and its spring sap has long been tapped for a light syrup.
Keep wilted, fallen, or storm-downed silver maple leaves and branches away from horses; wilted leaves can cause red blood cell damage (hemolytic anemia) in horses.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Most silver maples are grown straight from seed, but a couple of named selections fix the species' worst habits. These are the two you're most likely to find.
Silver Queen
Carries a tidier oval crown, sets little or no seed to clean up, and finishes the year in yellow.
Skinneri (Skinner's Cutleaf)
Stands out for its deeply cut, lacy leaves and the soft, weeping sweep of its branches.
How to propagate
Silver maple is easy to start, mostly because its seed sprouts so willingly. You can grow it from the fresh winged seeds it sheds or, with more effort, from summer cuttings.
SeedEasy
Sow fresh seed in late spring to early summer as soon as samaras ripen · 2 to 4 weeks to germinate; fresh seed germinates readily without stratification
Seed is the easy way to raise a silver maple. The winged samaras ripen in late spring to early summer, and because they barely go dormant you should sow them fresh the moment they drop. Planted right away they sprout in 2 to 4 weeks with no cold treatment needed.
Stem cuttingsModerate
Early summer from softwood · Several weeks to root under mist
You can also root softwood cuttings taken in early summer, standing them under mist where they strike roots over several weeks. It works, but the results are less sure than seed, so most growers reach for the samaras first.
Myths
All maples are poisonous to dogs and cats.
The ASPCA lists silver maple and the rest of the maples as non-toxic to both dogs and cats, so a curious pet that chews a leaf is in no danger. The real risk belongs to horses, and only from wilted or dried leaves, not the green ones on the tree. Keep fallen and storm-broken foliage out of any paddock and the worry disappears.