Red maple

Sun

Full sun to partial shade; autumn colour is usually strongest in sun.

Water

Keep young trees evenly moist. Established trees tolerate periods of wet soil and some drought, but prolonged dry conditions can cause leaf scorch.

Soil

Moist, acidic soil is best; tolerates clay and seasonal waterlogging. Avoid chalky or alkaline ground, where leaves often yellow.

Height

40-70 ft (12-21 m)

Spread

30-50 ft (9-15 m)

Flowers

Small red flowers in late winter or early spring, before the leaves; followed by paired winged seeds, often reddish.

Foliage

Opposite, three- to five-lobed green leaves with toothed edges and pale undersides; yellow, orange or red in autumn.

Growth

Moderate to fast, often 1-2 ft (0.3-0.6 m) a year while young.

Care needed

Medium

• Plant with the root flare visible at soil level, allowing room for the mature crown and keeping well clear of paving, drains and buildings.
• Water deeply during dry spells for the first two or three growing seasons; check soil moisture rather than watering by a fixed schedule.
• Spread 2-3 in (5-8 cm) of organic mulch over the root area, keeping it away from the trunk.
• Do not feed routinely; use a soil test before adding fertiliser or treating yellow leaves.
• Stake only if the root ball moves in wind, and remove ties and stakes after the first growing season.
• Avoid digging, compacting soil or raising the soil level over its shallow roots.

Pruning. Train young trees in late summer to retain a strong central leader and remove competing or poorly attached branches while they are small. Remove dead or hazardous wood when needed; avoid topping and heavy late-winter or spring pruning, which causes conspicuous sap bleeding.

Late winter

Check young trees for rubbing branches, damaged ties and weak forks; arrange professional assessment of large defects.

Spring

Watch for flowers and emerging leaves; test soil pH if new leaves turn yellow between green veins.

Late spring

Refresh mulch and remove unwanted seedlings while they are small.

Summer

Water young trees deeply during dry spells and check for leaf scorch.

Late summer

Carry out light formative pruning on young trees, removing competing leaders and crossing branches.

Autumn

Plant while soil is workable and moist; keep fallen leaves and pruned branches away from horses.

• Use as a specimen in a large lawn, with a broad mulched area beneath the crown rather than grass against the trunk.
• Place at the edge of a woodland garden with acid-loving shrubs for layered foliage and autumn colour.
• Use on moist ground beside a pond or rain garden, leaving room for spreading roots and the mature canopy.
• Plant as a long-term shade tree in a spacious garden, well away from patios and paths.

Garden styles it suits: Woodland, Wildlife garden, Autumn colour, Grand estate, New England and Bog garden.

Plant it with: Virginia sweetspire, Summersweet, Highbush blueberry, Oakleaf hydrangea, Cinnamon fern and Foamflower.

Wildlife: Early flowers provide pollen and nectar for insects. Birds and small mammals eat the seeds, and the canopy provides nesting cover; native caterpillars also feed on the leaves in its North American range.

• Yellow leaves with green veins: alkaline soil can prevent iron or manganese uptake. Test the soil before treatment; on chalky ground, replacement with a better-suited tree is usually more practical than repeated corrective treatments.
• Leaf scorch: brown leaf margins often follow drought, heat or root damage. Water deeply, mulch and protect the root area from digging and compaction.
• Girdling roots: roots circling the trunk can restrict growth and cause decline. Check nursery stock before planting and have an arborist assess established trees with buried root flares or constricting roots.
• Tar spot and other leaf spots: these usually cause cosmetic damage rather than serious harm. Collect affected fallen leaves and avoid routine fungicide use.

Not known to be toxic to cats, dogs or people. Leaves are highly toxic to horses, particularly when wilted or dried, and can cause life-threatening destruction of red blood cells. Keep horses away from fallen leaves, storm-damaged limbs and prunings; suspected ingestion requires immediate veterinary attention.

• Silver maple (Acer saccharinum)

  Silver maple has much more deeply cut leaves with long, narrow lobes and strongly silvery undersides; red maple leaves have shallower divisions.

• Sugar maple (Acer saccharum)

  Sugar maple leaves have mostly smooth-edged lobes and rounded U-shaped valleys between them; red maple leaves have clearly toothed edges and more angular valleys.

• Freeman maple (Acer × freemanii)

  This hybrid of red and silver maple often has more deeply divided leaves than red maple, but features overlap and nursery records may be needed for reliable identification.

The Latin rubrum means red, referring to the red flowers, buds, twigs and fruits that also give the tree its common name.

Propagation. Grow the species from fresh seed collected when the winged fruits mature, usually in spring or early summer. Many seed lots germinate promptly, though dormancy varies with origin. Named cultivars are usually propagated by grafting or specialist softwood cuttings;

Accepted botanical name

Acer rubrum

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Alabama, Arkansas, Delaware, Florida, Georgia, Illinois, Indiana, Kentucky, Maryland, Minnesota, New Jersey and New Mexico.

Measured

Soil pH 4.7 to 7.3. Average height 1500 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.