Maples have been widely planted in the urban landscape because they are so tough and tolerant of the urban environment. Not that we need even more maples on our tree lists, but if you are growing them or are planting more, you should know how the various forms and cultivars compare to each other. The Urban Sunset® Maple, Acer x platanoides ‘JFS -KW187’ 27545 is a close relative of the Pacific Sunset® and Norwegian Sunset® maples, relatively new maples that are so popular these days. The most significant difference between these three is that the Urban Sunset® has a more narrow growth habit than the others. Pacific Sunset® and Norwegian Sunset® maples can become incredibly wide.
Urban Sunset® Maple is noted to produce consistent red or burgundy fall color. They are relatively easy to transplant. They grow very fast, but usually do not exceed 35 to 40 feet tall by about 20 feet wide. From my experience, they appear to be drought tolerant and show none of the sagging leaf characteristics of red maple that looks pathetic during dry summers. The shade under mature specimens is so dense that turf will struggle. A ground treatment of arborist’s chips and woodland adapted groundcover plants and ferns is the best option.
Early and corrective pruning will be important to maintain a central leader on young trees. This type of maple is tolerant to wet or dry conditions and a variety of soil types. When planting, do not be afraid to disturb the outer root ball to cut away kinked, circling or girdling roots. You aren’t likely to harm these rugged roots and more likely to promote development of a stronger root structure.
Of some concern is that these ultra-tough maple trees are sometimes tough on urban infrastructure, with root strength to heave sidewalks and curbs. Roots are fast growing and aggressive, so don’t cram these trees into a small tree pit or narrow planting strip. However, if you have enough planting space and can contain or direct the roots, all of these Acer platanoides crosses are worth the effort.
The biggest downside to this cultivar is in the Acer platanoides parent species, which is very susceptible to Verticillium Wilt. If you find a maple dying from it, do not plant another in the same place as the disease is persistent in the soil. Fortunately, urban soils are not usually as likely to have Verticillium as agriculture soils, but it is important to be aware of when replacing dead or dying maple trees.
Urban Sunset® maple is a relatively new tree on the market. It is worth considering when you are looking for a fast-growing flashy tree of moderate size that does not demand perfect growing conditions. As always, let me know what your experience is with this tree.