The ash trees are part of the Olive family and most feature compound leaves with an odd number of leaflets. Ash species also produce a fruit known as a samara, a thin paper-like seedpod that hangs down in clusters from the branches of the female trees. Ash trees often are shade trees or street trees, with the wood of some ashes extremely valuable in the production of different products.
The white ash (Fraximus americana) is the member of the ash group that has the potential to grow the tallest. The 120-foot tall white ash trees growing in the Ohio and Tennessee river valleys were victims of the axe, as artisans coveted the wood for baseball bats, tennis rackets and hockey sticks, among other things. Most white ash trees growing wild today are in the 40- to 70-foot range. White ash typically has compound leaves with seven leaflets on one stem forming the complete leaf. The undersides of the leaves are a shade of white, giving the tree its name. The Floridata website describes the papery samaras that the white ash produces late in summer as resembling the wings of a dragonfly. Only the female trees have these, which will fall and create a nuisance under the tree. Various cultivars that will not produce fruit exist. Grow white ash in neutral or alkaline soil if possible and in full sun. The tree is a slow starter, but once established grows more rapidly. The tree will require room to grow and in a rural setting will attract animals such as deer and birds to eat its twigs and fruit.
Blue ash (Fraxinus quadrangulata) has from seven to 11 leaflets that are as long as 5 inches growing on a central stem that can exceed 1 foot in length. Blue ash may grow to 70 feet tall and acquired its name during the colonial times, when settlers could create a blue dye from the tree's inner bark. The sap from the inner layer of bark changes to blue if it is exposed to air. Blue ash foliage turns yellow in the autumn, and the tree produces samaras shaped like paddles, according to the University of Connecticut Plant Database website. Blue ash trees grow best in full sun and are easy to transplant. Choose a male tree if you wish to avoid the cleanup involved with the multitude of samaras in the fall. Blue ash grows native to states such as Ohio, Illinois, Indiana, Missouri, Kentucky and Tennessee.
Green ash (Fraxinus Pennsylvanica) grows in the eastern three-fifths of the United States. The Ohio Department of Natural Resources says the green ash is a preferred shade tree in urban areas, probably because it can grow despite the presence of air pollution and poor soils. Green ash has smaller leaves than most ashes, with 3- to 4-inch long leaflets on a 6- to 9-inch long stem. Green ash is among the first trees in fall to change colors, going from the dark green on the upper and lower surfaces of the leaf to a yellow-green. Green ash can grow to 60 feet high and be as wide as 40 feet. The tree has a reputation of being one of the healthier types of ashes, but it still falls victim to insect pests such as the ash borer beetle. Cultivars include the hardy Bergeson and the Patmore, a hybrid that will not produce the seeds that can be a problem in autumn.