Question
I a Leyland Cypress considered a bush or a Tree?
Why ?
I was wondering the root system structure of a Leyland Cypress is...tap root, shallow compact or large, transpalaning an 8 foot tall Cypress what is the proper ball size?  

Answer
Generally any plant that normally reaches a height of over 15 feet is a tree. Leland can be pruned annually and kept as a hedge rather than a tree. In the 1800's numerous tree species from all over the world were planted in an arboretum at Leighton Hall estate in England (Welshpool, Wales). In 1888 six unusual seedlings were noticed at Leighton Hall, apparently from a rare intergeneric cross between an Alaska-cedar (Chamaecyparis nootkatensis) mother tree and a nearby Monterey cypress (Cupressus macrocarpa). Both parent trees are native to the North-American Pacific coast. The new hybrid (Cupressocyparis leylandii) was called a cypress since the Alaska-Cedar is a "false cypress" and the Monterey cypress is a "true cypress." Neither are related to our southern baldcypress (Taxodium distichum).

It is a pyramidal tree, to 30-40 feet tall and 25 to 30 feet wide which makes it good for tall screen. It is graceful, somewhat open habit of growth. Give ample room, to allow for symmetry of growth. It grows well in a variety of soils, but prefers good drainage. It has few, if any, serious pest problems;

Most of the roots system is in the upper 2 feet on surface soil. It may spread out to about 2 the size of the crown foliage area.
The rootball needs to be 12 inches wide for every inch of tree trunk diameter and 6 inches deep per diameter  (a 3 inch tree needs a rootball of 36 inches wide and 18 inches deep). If it is to be move a distance than the rootball should be wrapped in a burlap cloth to keep in intact. This will weight quite a bit. The new hole should be twice the size of the rootball and as deep. Fill the excess with good potting/ top soil and mulch around the tree with not more then 3 inches thick of mulch.