Stately and beautiful, the Southern magnolia tree can grow to heights of 40 to 100 feet and as wide as 30 to 50 feet. It features wide glossy leaves and large, scented white magnolia flowers in spring and red seeds in fall. When adding any variety of magnolia to your landscape, choose the planting location carefully. Once established, this type of tree should not be moved. Follow these steps for successful planting.
Step 1 – Choosing Location
The Southern magnolia tree requires an area where it can freely grow. Consider the height and width at maturity before arbitrarily planting it in the ground. This evergreen magnolia needs a good 5 hours of sun daily, although it can tolerate partial shade when young. It will, however, require more sun as it matures. As for soil, it should be moist, well-drained and acidic, with a 4.5 to 6.5 pH.
Step 2 – Dig Hole
Use the shovel to dig a hole that’s twice as wide and twice as deep as the root ball. Remove all rocks, weeds and roots in the hole and put the dug-up soil off to the side.
Step 3 – Add Mulch
To give the Southern magnolia tree a good start, add a 4 to 6-inch layer of mulch in the bottom of the hole.
Step 4 – Position Tree
Place the root ball of the Southern Magnolia tree in the hole. Be sure that the top of the root ball remains level with the surface of the surrounding soil. Fill in with removed soil and tamp around the base of the tree.
Step 5 – Arrange Stakes
Pound wood stakes around the tree. Thread guy wire through an old or inexpensive piece of garden hose (for protection) and secure to the wood stakes. This will help stabilize the young tree during its early growth period.
Step 6 – Add Top Mulch
Add another layer of mulch to a depth of about 4 inches. For best results, use mulch made of pine bark, pine straw or leaves.
Step 7 – Water Deeply
Deeply water the newly-planted magnolia to get it settled into its new home. Continue weekly deep watering for the first 3 months, and then only water it during periods of drought.
Step 8 – When to Fertilize
Allow the Southern magnolia to become established. Follow a light but frequent (March, May, July and September) fertilization schedule for the first 3 growing seasons. Use an 8-8-8 or 10-10-10 fertilizer at a rate of 2 cups per 10 square feet. In the fourth growing year, decrease fertilizing to once or twice a year.
Step 9 – Pruning
Only prune the Southern magnolia tree when it is dormant—after the leaves have fallen. Gardening experts recommend thinning side branches while the tree is young. The idea is to maintain the tree’s natural pyramid shape. By leaving the lower branches alone, the tree will develop a dense canopy that can hide leaves as they drop.
Planting a Southern magnolia tree in the landscape should be a one-time event. Slow to moderate in growth, this specimen will grace the home garden for decades to come.