Acer macrophyllum, known as bigleaf maple or Oregon maple, is a majestic and ornamental tree highly prized in gardening for the spectacular size of its leaves and the beauty of its appearance. This species belongs to the family sapindaceae and is native to the west coast of North America, extending from Alaska to California and even populating rivers, valleys and deep soils of cool, humid regions.
Acer macrophyllum characteristics
- Height and crown: The Acer macrophyllum can reach reach between 15 and 20 meters in cultivation and up to 30 meters in ideal conditions. It forms a wide, dense, rounded canopy that can measure 6 to 8 meters wide, providing abundant shade.
- Sheets: Its leaves are the biggest within the genre Acer, with dimensions ranging from 15 to 30 cm wide, divided into 3 to 5 deeply incised palmate lobes. The 15-30 cm petiole, green with reddish tints, contains a milky juiceThe foliage takes on a spectacular yellow-orange or copper-brown hue in autumn.
- Flowers and fruit: La spring flowering It is quite showy, with 10-30 cm hanging clusters of pale yellow, fragrant flowers. It later gives rise to winged samaras 4 to 7 cm, grouped in hanging clusters of brown-yellow color, which facilitate the dispersal of its seeds by the wind
- Bark and branches: When young, the bark is smooth and brown; over time, it develops square-shaped plates. The green branches have small lenticels and are not hairy.
Location and environmental requirements
- Light and temperature: The bigleaf maple needs semi-shadow or filtered light to thrive, avoiding direct sunlight during peak hours, especially in summer. Although it can withstand intense cold and frost, it can withstand up to -15°C without problems, but it is important to protect it from very dry winds and strong thermal changes.
- Ground: It is demanding in terms of substrate: it requires acid soil (pH 4-6), fertile, loose, rich in organic matter, fresh, and with excellent drainage. It does not tolerate compaction or nutritional poverty. For optimal growth, see our section on maple tree care.
- Space: Due to its large size, this tree is ideal for spacious gardens, parks or as an isolated specimen where it can develop its canopy freely.
Irrigation and water management
- Frequent watering: Acer macrophyllum requires regular waterings, especially in summer, to keep the substrate constantly cool but never waterlogged. In the warmer months, it's recommended to water three to four times a week; in spring and autumn, every two to three days; and even less so in winter.
- Avoid excess and drought: Prolonged drought or overwatering can cause wilting, yellowing, and leaf fallUse well-draining soil and adjust the frequency according to ambient humidity and soil type.
Fertilization and fertilization
- Organic fertilizer: During the growing season (spring to fall), fertilize monthly with a layer of compost or mature manure about 2-3 cm around the tree, ensuring essential nutrients for vigorous development and autumn color.
- Winter reduction: Avoid fertilizing during winter or periods of extreme heat, when the tree's metabolism is slower.
Propagation: seeds and cuttings
- By seeds: It is multiplied by the seed stratification in winter. Soak the seeds in water for two days before sowing and keep them at cool temperatures (10-15°C) until germination in spring.
- By cuttings: The woody cuttings They can be taken in spring. It is advisable to use rooting hormones to improve the success of the process.
Transplant and post-transplant care
- Planting time: Recommended planting or transplanting in spring before sprouting, allowing the roots to develop before the summer heat.
- Land preparation: Use an acidic substrate, mixing compost, peat, and coarse sand for drainage. Don't reuse soil from other crops, and protect the tree from direct sunlight for the first month after transplanting.
Pruning and shaping
- Formation pruning: It is carried out in autumn or winter, after the leaves have fallen. It removes crossed branches, shoots from the base and structures the canopy to allow light passage and good leaf development.
- Pinching: With rapid growth, it is advisable to pinch new shoots in summer, keeping 2-3 mature leaves to control shape and vigor.
- Wiring: It can be done in winter, using paper-covered wire and removing it if marks appear. Don't overuse the wire, and prioritize other shaping techniques.
Diseases and pests
- Gall mite: It causes bumps on the leaves, but is not dangerous. Remove the affected leaves.
- Fungi: They attack roots and leaves, causing spots or death of branches. Prevent with proper watering and preventive fungicide treatments in spring and autumn.
- Aphid: It attacks tender shoots, controlling the pest with specific products and avoiding indiscriminate treatments to avoid damaging the environment.
- Prevention: Proper irrigation and pruning management drastically reduces pest and disease problems.
Ecological value and ornamental uses
- Ecological importance: Acer macrophyllum provides nectar, shelter and materials for wildlife such as birds, butterflies, and small mammals. Mature trees serve as microhabitats for mosses, ferns, and a wide variety of invertebrates.
- Traditional uses: In addition to being ornamental in large gardens and parks, its sap has been used to make maple syrup, and its wood is used in fine carpentry, furniture and in the manufacture of musical instruments.
El Acer macrophyllum It stands out not only for its beauty and landscape value, but also for its robustness, easy adaptation, and ecological relevance. Provided with frequent watering, a good substrate, and sufficient space, you'll enjoy its spectacular foliage and its unique presence in the garden for many decades.
