Sienna Glen® Maple is an excellent alternative to the commonly planted Autumn Blaze Maple with stronger wood and denser branching. Its uniform pyramidal shape and strong central leader make it a close substitute for Ash trees, but with better overall form. Its rich, dark green foliage turns from vibrant yellow-orange to burgundy in fall. This is a superb tree for tough sites with low maintenance.
Sienna Glen® Maple is an excellent street or specimen tree and is tolerant of salt, drought, flooding, alkaline soils, and pollution. Its stronger wood and tighter branch angles are less prone to breaking in wind storms and are easier to prune with age. The denser form of the tree provides excellent shade for patio spaces or western exposures.
Sienna Glen® Maple produces fewer samaras than the species and produces little direct food for wildlife. However, its tighter branching provides ample habitat for nesting birds and insects living on the tree will provide food for insectivores during the summer.
Sienna Glen® Maple requires little more than first year watering and a healthy mulch ring to perform well in most sites. As it has better branch angles and apical dominance (forms a strong central leader), Sienna Glen® Maple requires less frequent pruning than Autumn Blaze® Maple. However, the tree should be inspected by a certified arborist every 5-9 years depending on its growth rate. We invite you to check out the Arborist For Hire lookup at the Wisconsin Arborist Association website to find an ISA Certified Arborist near you.
The thin bark of Freeman Maples is prone to mechanical damage by animals or eager lawn enthusiasts with mowers. The trunk should be protected by a vinyl tree guard from Halloween to Memorial Day as a rule to prevent buck rub. Avoiding mower and yard equipment damage is easy if you use a mulch ring to avoid mowing near the trunk.
Like all maples, Sienna Glen® Maple can develop Tar Spot (Rhystima spp.) fungus, which is purely cosmetic and unlikely to cause any lasting damage to the tree.
Suckering may be present on old pruning wounds or damaged trunks. While this is best avoided by having a professional arborist care for your tree, suckers can be pruned as they appear to slow/stop their presence. Take care to avoid damaging the trunk tissue as this will cause even more suckers to appear.
Leafhopper, scale, and other insects can feed on the leaf tissues of Sienna Glen® Maple. If excessive damage is observed, or you see individual branches dying (also called Flagging), contact a certified arborist to develop a plant health management plan. Flagging can be a sign of fungal diseases like Verticillium Wilt, which are best diagnosed by a professional.
Freeman Maples are noted for their fast growth, uniform habit, and reliable fall color. However, these trees have been heavily planted in the last 30 years since the introduction of the original Autumn Blaze® Maple (US Plant Patent 4864) in 1980. While the trees have beautiful fall color, please consider diversity when selecting them for planting. If you or your neighbors already have a Freeman Maple cultivar in the landscape, it is recommended to pick a different, non-maple (Acer) species for your landscape. Remember, Emerald Ash Borer and Dutch Elm Disease were problematic because we relied on only one tree for our boulevards. Let’s not make the same mistake with Freeman Maples.
Sienna Glen® Maple was discovered in 1990 on an abandoned farmstead in Lake Elmo, Minnesota by Dennis Heins of Heins Nursery. It was selected for its denser branching and uniform, pyramidal habit when compared to other common cultivars. In trials, Sienna Glen® Maple has demonstrated excellent resistance to wind damage and better tolerance of alkaline soils. It is less prone to chlorosis (yellowing leaves) compared to other Acer x freemanii cultivars.
If you’re grouping trees, pair Sienna Glen® Maple with trees that are of fine or coarse texture and provide different fall color. Consider using Kentucky Coffeetree, Northern Catalpa, or Exclamation! London Planetree as coarse-textured plants to complement the average texture of Sienna Glen® Maple. For more fine textured plants, use Katsura Tree, Corneliancherry Dogwood, or J.N. Strain Musclewood.