The sunset maple tree (Acer rubrum “Red Sunset”) is a cultivar of red maple prized because of its rapid development and brilliant fall foliage. Hardy in U.S. Department of Agriculture zones 4b through 8b, the sunset maple thrives in both wet and dry conditions, and tolerates a wide array of soils. However, as a tall tree with a broad canopy spread and an extensive root system, sunset maples require plenty of open space to stay healthy and grow to their full potential.
The sunset maple typically rises to a height of 45 to 50 feet, and prefers full to partial sunlight. Therefore you should not plant sunset maples under power lines or other overhanging structures which will obstruct their vertical growth, or near tall buildings or other trees which may block their lighting in the south.
The sunset maple includes a spread of 25 to 40 feet. The tree’s dense canopy makes it popular as a shade tree in parks and yards, and as a street tree in places where sidewalks do not inhibit root development. However, for long term landscaping, do not plant sunset maples within 40 feet of different trees or structures, since this could stunt their canopy development.
Sunset maples can adapt to constrained spaces if regularly irrigated, but prefer open areas with ample soil space for root development. The tree’s root system can extend for as many as 80 feet, and often includes large surface roots which could upheave lawns or paving stones. Sunset maples which are prevented from developing adequate root systems might show signs of anxiety including dry or yellowing leaves, and might eventually die if unable to obtain sufficient nutrients and water.
In good circumstances, sunset maples can grow up to 24 inches per year. While a seedling begins small, it is going to expand quickly in both spread and height, and will soon come into battle with neighboring trees or structures if not given sufficient distance. Plan ahead to permit your sunset maple the space it has to obtain enough sunlight, nutrients and water to thrive for years to come.