Which Trees Absorb More Sunlight?

Maple leaves absorb much light.

The shape and size of a tree's leaves determines the amount of sunlight it absorbs. While all foliage takes in light and uses chlorophyll transforming energy through photosynthesis, trees with broad, flat leaves take in more light as compared to trees with smaller or needlelike foliage. The larger the leaf surface, the more light absorbency. When planting broadleaved trees in your landscape, consider both their mature size and the amount of shade they create.

Maples

Maple trees (Acer spp.) absorb large amounts of sunlight with their wide, flat foliage. These deciduous trees range in size from 8-foot tall, shrublike varieties to the 100-foot tall sugar maple. Most maples have palmate, three- to 11-lobed leaves displaying showy, fall colors. At up to 15 inches wide, bigleaf maples (A. macrophylla) have the largest leaves. The Norway maple (A. planatoides) has five-lobed leaves and a dense canopy creating very deep shade on the ground. The redvein (A. rufinerve) has 6-inch, three-lobed foliage, as does the Manchu striped maple (A. tegmentosum). Other large-leaved, light-absorbing maples include the fullmoon (A. japonicum) and devil (A. diabolicum).

Oaks

Oaks (Quercus spp.) are among the most light-absorbing trees. These deciduous trees range from small, evergreen species growing to 30 feet tall to large, deciduous shade trees reaching heights to 100 feet. Oak tree foliage either has pointed, slightly bristly tips, or smooth, rounded tips. The red oak (Q. rubra) has 8-1/2-inch leaves with seven to 11 lobes. It casts very dense shade beneath its spreading canopy. The post oak (Q. stellata) has 8-inch wide foliage with two or three lobes and the shumard red oak (Q. schumardii) has 8-inch, simple foliage. Other large-leaved oaks include the white (Q. alba), sawtooth (Q. acutissima) and Southern red (Q. falcate).

Lindens

Lindens (Tilia spp.) have large, light-absorbing leaves. These deciduous trees grow rapidly creating dense shade under their canopies. Commonly grown ornamentals include the bigleaf linden (T. platyphyllos), an 80-foot tall tree with 5-inch, simple foliage. The bee tree linden (T. heterophylla) has 7-inch, lustrous foliage with fuzzy undersides. Other large-leaved lindens include the silver (T. tomentosa) and Crimean (T. x euchlora).

Other Absorbent Trees

Other trees absorbing large amounts of sunlight with their large, broad leaves include catalpas (Catalpa spp.) and magnolias (Magnolia spp.). The deciduous Southern catalpa (C. bignonioides) has 8-inch foliage that grows in a whorled form. The Northern catalpa (C. speciosa) has 12-inch leaves that turn yellow-brown in fall. Both are native to North America. The bigleaf magnolia (M. macrophylla) has 12- to 32-inch, light-green foliage and a very low canopy. The saucer magnolia (M. x soulangiana) has deciduous, 6-inch leaves. This small, multistemmed tree has a low, spreading canopy.

References

• Penn State; Leaf Shapes and Strategies; July 2009
• University of Connecticut; Growing Lawns Under Shaded Conditions; Steven Rackliffe
• Virginia Cooperative Extension; Selecting Landscape Plants: Shade Trees; Diane Relf, et al.
• University of Nebraska - Lincoln; Trees in the Home Landscape; Anne M. Streich, et al.; August 2007
• University of Missouri Extension; Tree Placement on Home Grounds; Tree Placement on Home Grounds; Christopher J. Starbuck; October 1999
• Clemson Cooperative Extension; Maples; Debbie Shaughnessy, et al.; November 2006

Resources

• Reed College; Maples; August 2004
• The Ohio State University: Tilia
• N.C. State University; Trees; Erv Evans