Magnolias are magnificent flowering plants featuring blossoms in white, pink, red, purple, or a more recent development, rich yellow. These plants show a remarkable variety of leaf shapes and plant forms. New varieties and hybrids appear every year, but distribution is spotty in local nurseries. Many more kinds are available from mail-order specialists.
Magnolias include both evergreen and deciduous types. Most have large, striking blossoms composed of petal-like segments, but a few are grown for use as foliage plants.
For any magnolia, choose the planting site carefully—virtually all of these trees are hard to move once established. Magnolias never look their best when crowded. Pick a location where the shallow, fleshy roots won’t be damaged by digging or by soil compaction from constant foot traffic. All magnolias may be used as lawn trees; try to provide a good-size grass-free area around the trunk, and don’t plant under the tree.
Magnolias appreciate fairly rich, well-drained, neutral to slightly acid soil amended with plenty of organic matter at planting time. They will grow in somewhat alkaline soil but may develop chlorosis. At least in the early years, keep a cooling mulch over the root area.
Irrigate deeply and thoroughly, but don’t waterlog the soil or the tree will drown. Only M. virginiana can take constantly wet soil.
Feed trees if new growth is scanty or weak, or if you see significant dieback despite adequate watering and drainage; use a controlled-release product. Treat chlorosis (lack of iron—common in alkaline soils—that shows up as yellowing between leaf veins) with iron chelates.
Leaf damage can result from excess mineral salts in the soil or salts in irrigation water. The latter is a problem in Southern California and, typically, the factor limiting success of magnolias in desert regions. Frequent heavy waterings will help leach out salts and carry them to lower soil levels—as long as drainage is good.
Native to the southeastern United States. Growing to 80 ft. tall and 60 ft. wide, this can be a street or lawn tree, or in its smaller forms a big container plant or wall or espalier plant. It’s unpredictable in form and age of bloom. Grafted plants are more predictable, but need pruning to become single-trunked trees; otherwise, this can grow as a multitrunked tree. Its glossy, leathery leaves are 4–8 in. long.
Southern magnolia needs a warm location (or a warm wall) to perform well in Zones 4 and 5. Give it a wind-sheltered spot in the desert. In Hawaii, it does best in Zone H1 and in the inland valleys of H2; and of course it grows well all over mild parts of the South.
Flowers are pure white, aging to buff; they’re also large (8–10 in. across) and powerfully fragrant. Most have six segments. Blooms appear throughout summer and fall.
‘D. D. Blanchard’: Grows into a handsome pyramidal tree to 50 ft. tall and more than half as wide. Lustrous dark green leaves are orange-toned brown on undersides.
‘Little Gem’: Tops out at 20–25 ft. tall and 10–15 feet wide. Its narrow form makes it good in a container, as an espalier, or in a confined area. It branches to the ground. Half-size leaves are dark green above, rusty beneath. Small (5–6-in.-wide) flowers appear from spring through late summer, but fewer blooms form during mid-summer heat.
‘Majestic Beauty’: Vigorous, densely-branching tree develops a broadly pyramidal form, grows to 35–50 ft. tall and 20 ft. wide. Leaves are exceptionally long, broad, and heavy, and flower scan be 1 ft. across.
‘St. Mary’: This is a good choice where standard-size Southern magnolias would grow too large and too fast. Left alone, it will form a 20-ft. tall and wide, dense bush, but it can be trained as a small tree. Good plant for containers and espalier. It is a heavy producer of 8–10-in. flowers. Can grow higher in old age.
Native to the southeastern United States. Growing to 80 ft. tall and 60 ft. wide, this can be a street...
Slow to moderate growth to 6–8 ft. tall and 3–4 ft. wide. Old clumps may be wider than tal...
Deciduous shrub or small tree. In warmest parts of the range, grows fast to make a tree to 25 ft. tall...