Magnolia trees (Magnolia grandiflora), with their glossy dark green foliage and waxy white blossoms, are an enduring symbol of the South. Southern magnolia trees are hardy in zones 7 to 9, though some species will thrive in parts of zone 6. These very large trees may grow up to 80 feet tall and are often planted by themselves as specimen trees. The large white flowers give off a very sweet perfume. The red seeds may be dried and used to make jewelry, and the leaves may be preserved for use in floral arrangements.
Dig a planting hole for your new Southern magnolia tree that is the same depth as the root ball of the nursery stock or magnolia seedling and twice as wide as the root ball. Remove any rocks or tree roots from the hole and break up any large dirt clods.
Settle the seedling into the hole, adding soil back into the hole if necessary to insure that the top of the root ball is even with the top of the hole. Fill in around the roots of the seedling and water lightly to settle the soil.
Spread mulch around the base of the tree to discourage weeds and conserve water. Use 3 to 5 inches of organic mulch, such as compost or bark mulch.
Water your magnolia tree regularly during dry periods. Southern magnolias prefer moist soil, though established trees will more readily tolerate dry periods. According to the University of Georgia Cooperative Extension, magnolia roots extend three times farther than the width of the tree, so the tree can draw water and nutrients from a wide area.
Fertilize a young Southern magnolia tree after it is established and producing new growth. The University of Georgia Cooperative Extension recommends 1 cup of 8-8-8 or 10-10-10 fertilizer sprinkled underneath the tree around the edges of the planting hole in March, May and July of the first year.
Fertilize with 2 cups of 8-8-8 or 10-10-10 fertilizer in March, May and July of the tree's second year, sprinkled in a wider circle around the base of the tree. Increase the fertilizer amount to 4 cups in the tree's third year. Older Southern magnolia trees should not need additional feeding.
Prune dead or broken branches. You may prefer to remove low-hanging branches to make mowing beneath the Southern magnolia tree easier, or you can allow the low branches to shade out grass beneath the tree and eliminate the need to mow.