Red Cascade Mountain Ash

The Red Cascade Mountain Ash (Sorbus americana ‘Dwarfcrown’) is first a tree of limited height and width, reportedly growing no more than 20 ft. tall and 8 ft. wide. It has clusters of white flowers that turn eventually into orange, then red fruit, smaller than a marble. Green pinnately compound leaves turn yellow in fall, some years with quite a spectacular show. They sometimes emerge with a yellowish edge in the spring.

This is a straight and narrow tree with stout twigs, growing almost candelabra like from the main leader. We have seen no insect or disease problems. As far as messy fruit, in most areas the birds strip the tree of its berries before they hit the ground, but I don’t think you can count on that every year.

We have found this tree easy to grow and transplant with minimal pruning required. This is a favorite street tree in Mount Vernon for the Parks Maintenance Supervisor because he says he can just about forget about this tree after its established. It maintains a relatively short oval form on its own.

We have also found this tree to be a very tough survivor. Many trees planted in tough locations with minimal maintenance (watering) will end up with dieback (Raywoods, Crabs, Cherries, Oaks). This tree responds to drought with smaller leaves and canopy, apparently until the root system becomes established. This is especially a nice feature where watering is inadequate.

I have seen excellent specimens growing in small 24”x24” sidewalk openings for the last several years. Some have been run into, abused, and neglected, but still perform quite well. If you are looking for a tough street tree with a compact crown for under power lines, where fruit may not be a problem, the Red Cascade Mountain Ash is a good selection. It can also be quite showy in the spring and fall for a special garden location. Let me know what your experience has been with this tree.