Acer rubrum

Red Maple Care & Identification Guide

The magnificent Red Maple (Acer rubrum) is a colossal and highly spectacular deciduous native of Eastern North America, celebrated globally for its rapid growth rate, broad soil adaptability, and vibrant red features. Frequently called the Swamp Maple, it thrives in wet soils where other trees suffocate. It exhibits three-lobed leaves with sharply serrated margins, carried on long red petioles. Warning: Its wilted leaves are extremely toxic to horses. It requires consistent moisture, full sun, and acidic soil.

Sunlight Full Sun

Watering Moderate to High

Soil Mix Wet Acidic Soil

Temperature -35°C to 28°C

Toxicity Toxic to Horses

Botanical photography of Red Maple (Acer rubrum) - Plant AI care database

How to Identify Red Maple

Identify Red Maple immediately by its highly distinct biological features. Native to its specific ecosystem, it showcases spectacular foliage and structural habits optimized for its environment.

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Distinctive Features: Broad symmetrical crown, three-lobed leaves with sharply serrated edges on bright red stems, and smooth silver-grey bark that turns furrowed with age.
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Typical Coloration: Medium green summer foliage with pale silver undersides, turning to a breathtaking, uniform fiery crimson or glowing orange-scarlet in autumn.
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Potential Confusions: Similar to Sugar Maple, but easily distinguished by its sharply serrated leaf margins (Sugar Maple has smooth margins) and V-shaped sinuses.

11-Step Professional Care & Planting Guide

💧 【Watering & Moisture】 Water moderately to highly. Prefers consistently damp, moist soils and can easily tolerate temporary flooding. Never allow the soil to dry out completely.

☀️ 【Sunlight & Exposure】 Requires full direct sun. Highly valued as a fast-growing shade tree; needs open sky to develop its brilliant red autumn color.

🪴 【Ideal Soil Mix】 Requires moisture-retentive, highly acidic soil. Blend 50% clay-loam, 30% organic peat moss, and 20% compost (pH 5.0-6.0).

🌡️ 【Temperature & Winter Care】 Extremely cold-hardy (USDA Zone 3-9). Highly resilient to sub-zero temperatures and icy winters. No protection required.

✂ 【Pruning & Grooming】 Prune in late summer or early winter to remove crossing branches. Avoid spring pruning to prevent excessive sap bleeding.

🧪 【Fertilization】 Feed in early spring with an acidic slow-release organic fertilizer. Mulch with pine bark to maintain soil acidity.

🏺 【Potting & Garden Planting】 Plant in wet, low-lying garden areas or near ponds. Dig a wide hole twice the root ball, backfill with acidic loam, and mulch deeply.

🌱 【Propagation】 Propagated by sowing seeds in summer. Unlike other maples, Red Maple seeds mature in spring and germinate immediately without stratification.

🐛 【Common Pests】 Watch out for leafhoppers or gall mites. Spray with organic neem oil or manually prune heavily infected twigs.

🦠 【Common Diseases】 Susceptible to tar spot or verticillium wilt. Maintain highly acidic soil to prevent iron chlorosis (yellow leaves with green veins).

🎓 【Botanist Advice】 Extremely critical warning for horse owners: Wilted red maple leaves are highly toxic to horses, causing severe hemolytic anemia. Never plant them near pastures or horse paddocks!

Frequently Asked Questions

Why is it called Red Maple?

Because red is its signature color! It produces red flowers in early spring, red young twigs, red leaf stalks (petioles), and brilliant red autumn foliage.

Is the Red Maple safe for dogs and cats?

Yes, Acer rubrum is completely non-toxic and pet-safe for cats and dogs. However, its wilted leaves are highly toxic to horses.

Can the Red Maple grow in wet, boggy clay?

Yes! Also known as the swamp maple, it is one of the few large trees that thrives in wet, poorly drained soils and can withstand seasonal flooding.

How do I fix yellow leaves with green veins (chlorosis)?

This indicates iron chlorosis due to alkaline soil. Apply elemental sulfur, peat moss, or chelated iron to lower the pH and release trapped iron to the roots.