Mulberry (Morus) is a tree that grows rapidly to a height of 80 feet and belongs in the family Moraceae. The three varieties of mulberry trees are white, black and red. White mulberries are the cold-hardiest and are native to China, and the black mulberry is least cold-hardy and is native to western Asia. The red mulberry is native to the eastern U.S. and is cold hardy to sub-zero temperatures. Mulberry trees grow best in soil that drains well, so clay-laden Arizona soils will require amending before planting the tree.
Select an area in the landscape situated in full sun and is large enough for the mulberry tree to reach full size. The mulberry tree will require a space of 15 feet in diameter on all sides so structures or plants will not interfere with its growth.
Mark off a 10-foot by 10-foot section where you will be planting the mulberry tree by spraying the area with paint. The mulberry requires amending of an area of this size so the roots will spread out properly.
Clear the planting site of any weeds or other vegetation. Dig the vegetation out by hand or use an herbicide to kill it. Wait several weeks before placing the tree into the ground, if herbicides are used. This will allow enough time for the poison to wash from the area.
Spread one cubic yard of compost or manure over the planting site. Work it into the soil using a tiller or shovel, to a depth of one foot.
Spread one cubic yard of builder's sand or course sand over the planting site. Work it into the soil as you did the compost. Water the planting site.
Dig a hole that is three times wider that the mulberry's root ball but is no deeper that the tree is growing inside the container.
Remove the mulberry tree from its container. Loosen the root system if bound tightly together or has become pot-bound. Place the tree into the planting hole.
Fill the hole halfway with soil and pack down firmly around the base of the mulberry tree. Fill the remainder of the planting hole with soil and pack down again.
Water the mulberry tree in well. Continue watering the tree two to three times per week for the first three weeks. Water regularly once per week thereafter, as mulberry trees are quite drought-tolerant once established.