Jos Van Hage
If you are looking for a deciduous tree that will give year round beauty then perhaps the mountain ash is what you are looking for.
One of the most popular ornamental trees the mountain ash provides year-round interest as it goes through the seasons. In the spring the tree produces clusters of tiny white flowers which are followed by red or orange berries in the fall.
These berries can remain on the tree throughout the winter or until the birds eat them, which is another feature of the tree, as it attracts birds. This time of year the tree stands out because of its delicate fernlike foliage that in the fall turns red and orange. The tree often has a nice form and the bark on some varieties is also attractive, making it a tree for all seasons
There are several varieties that have proven to grow very well in Prince George's Zone 3 climate. Varieties such as "American," "European," "Russian," "Showy," "Cardinal Royal," "Pyramidal," and "Oakleaf" have all been growing here very successfully. All these have different qualities. For example "Showy," the hardiest of all the mountain ashes has a long blooming time and the flowers and dark green foliage are very showy along with its scarlet red berries and smooth grey bark.
It is small (20-25 feet high), narrow (16 feet wide) and slow growing. An even narrower variety is the "Pyramidal" which grows only 6-8 feet wide and 20 feet tall, and is also very slow growing, with smooth olive green bark. If you are looking for height the "Cardinal Royal" grows 40 feet tall and 20 feet across. It has a straight growing trunk and uniform upright branches. The dark green foliage is silvery underneath and the berries are bright red.
The "American" and "European" are quite similar but the American tree is smaller, growing 20 feet high and 16 feet wide, while the European can grow up to 35 feet tall and spread 20-25 feet across. A mountain ash with a different leaf is the "Oakleaf, with its three- inch matte green leaf with a white underside is similar to those of the English oak tree. The oakleaf mountain ash produces the clusters of white flowers and fall orange/red berries and has smooth olive green bark and a nice shape.
Choose a site that receives full sun and where the soil is well drained, as mountain ash do not like to have their roots sitting in water for any length of time. Stay away from low lying wet areas. They prefer to be grown on a mound especially if you have clay soil. They are a low-maintenance tree requiring very little to no pruning. Any pruning should be done in early spring just as the buds begin to swell.
Applying lime sulphur and dormant oil to the tree in the spring before the leaves break out will help prevent any pests or disease.