Magnolia Grow Guide
For us, nothing says Southern charm more than a Magnolia. Their fragrant, beautiful flowers adore the glossy leaves – Leaves that, at times, stay around all year long.
There are some 125 species of magnolias, several of which are important ornamentals with many named cultivars. There are shrub-like deciduous magnolias and huge evergreen forest-tree magnolias. The Asiatic species, star magnolia (M. stellata) and saucer magnolia (Magnolia × soulangeana), bloom in early spring before their deciduous leaves come out. The American species, southern magnolia (M. grandiflora), is evergreen and blooms in summer. The sweetbay magnolia (M. virginiana) of eastern North America is evergreen in the South and deciduous up North.
Some of our favorite magnolias include ‘Bracken Brown Beauty’, a relatively cold hardy cultivar of southern magnolia with a dense pyramidal form, and ‘Little Gem’, a smaller, compact version of the same species. Among the deciduous mags that bloom in early spring on bare branches are ‘Alexandrina’ and ‘Ann’, both hybrids of Asian origin and of considerably smaller stature than the American species.
The conical shape of M. grandiflora and its cultivars extends all the way to the ground and their dense evergreen foliage won’t allow grass or much of anything to grow under them. Additionally, the evergreen varieties drop their large leaves year round, and if you want to maintain a pristine landscape, this means frequent policing of spent leaves. Know that southern magnolia can get very big, up to 90 feet tall!
The deciduous Asian magnolias are smaller, sometimes mere shrubs, and provide brilliant color early in the spring.
Here is a quick comparison chart of the varieties we carry:
Most magnolias do best in a neutral to slightly acidic soil that stays relatively moist but is still well drained. The soil should be fertile, rich in humus, and loamy. It is not advisable to add any kind of amendment to the planting hole as the tree’s roots will soon spread beyond the hole anyway. Instead, choose a location with good soil.
Magnolias prefer full sun to partial shade, so choose a spot in your landscape that receives sunlight for at least six hours a day.
Most magnolias should have protection from strong winds because:
- The large leaves of many species are damaged by strong wind;
- Magnolia limbs tend to be brittle; and
- The flowers of those that bloom on naked branches before the leaves unfold are susceptible to wind burn and damage.
Note the USDA climate zones for your magnolia and select a planting site that can offer protection from summer heat or winter cold, as necessary. For example, the growing zones for Little Gem magnolia are 7-9, so if you are in zone 6 or 7, position your magnolia where it will be protected from the coldest winds and temperatures, such as near a south facing wall. If you are planting a Little Gem in zone 9 or 10, position it where it will get afternoon shade.
Planting Your Magnolia
Plant magnolias in fall or spring – preferably spring.
- Dig the planting hole as deep as the magnolia is in the nursery pot and twice as wide.
- Thoroughly wet the soil in the pot before starting. Place the pot on its side and slide the root ball out. If the plant is stuck, you can slip a long-bladed knife around the inside edge to loosen it. Gently loosen some of the roots along the sides and bottom, and pull them outward so they are not encircling the root mass. It might be necessary to prune some of the roots if they are growing in a circle around the inside of the pot.
- Build up a rounded mound of soil in the middle of the planting hole. Place the root crown on top of the mounded soil so that the top of the crown will be at ground level. Spread the side roots out over the mounded soil while backfilling the hole. Work the soil in and around the roots. When the hole is half filled, give it and the roots a good soaking of water. When the water has drained, readjust the depth of the stem if necessary and finish filling the hole. Gently tamp the soil down with your hands.
- Use your hands to build up a 3-6 inch high embankment of soil on the ground over the outside of the root zone. This will help impound water over the roots while it sinks into the soil. Water thoroughly. Spread 3-6 inches of an organic mulch over the root zone and beyond to help hold in soil moisture. You can use hay, straw, leaves, pine needles, grass clippings or compost. Do not use mushroom compost as this contains lime and will raise the pH.
Caring for Your Magnolia
If planted in the spring, provide at least one inch of water per week for the first six months or so. Fall-planted mags can be watered every two weeks. Once established, most magnolias are quite tolerant of dry periods.
- Use stakes and lines to stabilize a new magnolia against the wind.
- An organic mulch over the root zone helps retain soil moisture. Be sure you don’t use a mulch that contains lime, as this could cause yellowing of the leaves. If chlorosis does occur, a foliar application of chelated iron can help.
- Do not fertilize a newly planted tree until the following growing season. Then for the next two or three years, feed with a balanced fertilizer every other month during the growing season. After the first two or three years, fertilize just once or twice a year.
- Do any necessary pruning and shaping while the tree is still young because removing large branches can leave scars that are open to infection.
- Magnolias are more trouble-free than many trees, and minor problems such as scale insects or leaf miners can be ignored.
Magnolias are a great addition to any landscape, even when they’re not in season. Their attractive mounded shape all year around make it an exceptional choice as an accent tree for your garden. Your landscape will be filled with a fragrant aroma and a southern charm you can’t deny!