The Ash tree, Fraxinus excelsior, is a fast-growing deciduous tree, native to the U.K. and Europe. The wood is tough, popular for making tool and sports handles, and furniture. A large tree, it needs plenty of space if grown as a specimen tree and is only suitable for very large gardens or wild/woodland areas. However it's possible to grow ash in smaller spaces by coppicing (cutting back to the ground in winter) or as part of a hedge.
Fraxinus excelsior forms a tall, domed head of branches and is easily identified by its large green leaves divided into eight to 12 leaflets that turn yellow in autumn before falling. Bark is smooth and pale brown to grey, and conspicuous black buds are arranged opposite each other along the stems, most visible in winter. Through autumn, winged seeds are borne in clusters, these are designed to spin through the air and spread themselves widely, so if there's an ash tree in your area, watch out for self-sown seedlings and remove them as soon as possible. Ash is fast-growing and reaches much of its mature size in around 25 years.
However, Fraxinus excelsior is not a good planting choice currently, due to Ash Dieback Disease (Hymenoscyphus fraxineus). This has become widespread in many areas of the U.K. and poses a serious threat to ash trees. Symptoms include black lesions on stems, black blotches on leaves, and extensive dieback of shoots and branches. This disease attacks plants only in the Oleaceae family, which includes the garden shrubs Phillyrea and Chionanthus. Affected trees become unstable and usually need felling to avoid becoming a danger to life.