Although there are magnolia trees that may grow as tall as 80 feet in parts of the south, short-growing varieties may be planted as shrubs or placed in containers or wells. Magnolias are popular for landscaping because they are generally pest- and disease-free. You may purchase magnolia varieties commercially from local nurseries for pick-up or delivery, or purchase them by phone from specialty nurseries and have them shipped bare-root.
Read a farmer's almanac or gardening book, or consult the USDA website to determine your hardiness zone. This will help determine which magnolias you can grow. Popular magnolia trees, such as Southern magnolia, will grow well in zones 7 through 9. Hardier magnolia trees, such as saucer magnolia, will grow well in zones 4 through 9, and are suitable for landscapes in the upper Midwest. Magnolia trees listed in nurseries and tree catalogs are usually tagged with USDA hardiness ratings.
Examine trees in nurseries before purchasing to ensure they are healthy and disease-free. If you purchase trees by mail, examine each tree before accepting delivery. If the tree is damaged, refuse delivery and contact the supplier.
Walk away from the tree and look at its overall appearance. Young magnolia trees should have a balanced, pyramidal shape. The tree should have dense foliage. Sparsely foliated trees may be unhealthy due to a wide range of factors, including stress from lack of water, fungal infection or root rot.
Pick a leaf from a tree and look it over. Although magnolias have few problems with pests or diseases, any issues that the tree has will leave signs in the leaves. Look for tiny shield-shaped "scale bugs." Scale bugs may also leave a sweet-sticky substance known as honeydew. Honeydew is a breeding ground for mildew, which may appear on leaves and branches of a tree as a black, gooey residue. Other issues that may appear on magnolia trees include black spot, which leaves black spots on the leaves. Although these problems will not kill established trees, they can weaken them.
Examine each branch of your tree for signs of breakage or rough handling. Magnolia trees may also suffer from cankers, which leave holes in the tree's thick bark. Cankers appear when a magnolia suffers from fungal infections.
Look over the trunk of a magnolia for scars. Scars in a magnolia's trunk may occur from lawn care tools. These scars can create an opening in the tree's thin bark that will let in fungal infections. Signs that a tree may already have fungal infections include mushrooms; conks or plate fungus growing from the bark; or cankers that occur when the bark separates from the heartwood of a magnolia due to threads of fungus growing between the two layers.
Peel back the burlap cover from a balled and bagged or bare root tree; or, lift the root ball from a tree that was either grown in a container or tree-spaded and then placed in a container. Signs of root damage include broken, brown and brittle roots. Roots in this condition may be rotten or show signs of stress from lack of water. Magnolia trees are also prone to root girdling (when roots wrap around the trunk and choke it). Roots should be green and succulent and should not wrap around the trunk of the tree.