Its huge, early spring blooms appear before its broad, dark green leaves. Saucer magnolia flowers may continue to bloom after the leaves emerge, usually blooming for one to two weeks. Saucer magnolias are messy, but since it has a short bloom time, it’s not a prolonged clean-up period. The spectacular, refreshing display makes the clean-up worth it. The native saucer magnolia species has pinkish-white flowers, but many cultivars are available with pure white, pure pink, magenta, and purple flowers. The plant has a nicely rounded crown, making it an ideal landscape specimen. It grows moderately, about 12 to 24 inches each growing season. Saucer magnolia heights can reach 25 feet tall, with a spread of 20 to 30 feet wide. Saucer magnolia’s rope-like tree roots grow horizontally to provide stability. Its roots do not grow invasively or deeply like other types of magnolia trees that can affect a home’s foundation if planted too close. Pruning can be done to shape the plant into a tree form, and you should prune diseased and broken branches away to prevent the spread of fungal diseases. These plants often do fine without any feeding, but a spring application of fertilizer can help the plant thrive. The branches of saucer magnolia trees are favored by wildlife as nesting sites, and their seeds are a food source for birds. This tree is also moderately pollution tolerant.
Light
Saucer magnolia trees prefer full sun, but they can tolerate partial shade locations.
Soil
Though they will tolerate clay soils, saucer magnolia trees do best in moist, acidic, organically rich, and well-drained, loam.
Water
During the first year of planting, water the tree deeply and frequently. Afterward, saucer magnolias need irrigation only when the weather is dry. Once established, these trees have a moderately good drought tolerance.
Temperature and Humidity
Cool, rainy weather tends to cause fungal leaf spots and cankers on magnolia plants. They can handle a wide range of humidity. If possible, avoid splashing soil from the ground onto the plants, and give them good air circulation.
Fertilizer
Magnolias are not heavy feeders, but they benefit from mixing fertilizer into the soil when planting, then lightly feeding them each spring with a balanced slow-release fertilizer. For annual spring feeding, do not mix the fertilizer into the soil; spread it over the surface around the plant, then water it in.
Types of Saucer Magnolia
Alexandrina (M. x soulangiana ‘Alexandrina’): This multi-stemmed variety grows 20 to 30 feet high. This saucer magnolia hybrid is a cup-shaped plant with deep rose-purple flowers with white inside.Rustica Rubra (M. x soulangiana ‘Rustica Rubra’): This plant grows 15 to 25 feet high with a broad, open, pyramidal form. The flowers are rose-red.Verbanica (M. x soulangiana ‘Verbanica’): This cultivar grows 10 to 15 feet high with an upright, broad, pyramidal form. The flowers, which appear later than other varieties, are cup-shaped and rosy-pink flowers with white inside. Lustrous dark green leaves turn coppery brown in fall.Lennei Alba (M. x soulangiana ‘Lennei Alba’): This plant grows 12 to 24 feet high and wide with a broad, pyramidal form, making it ideal for small gardens. This saucer magnolia hybrid’s flowers are pure white and globe-shaped; this tree flowers slightly later than the primary species.
Pruning
Saucer magnolia trees often produce multiple stems. To shape it into a tree form, prune away all but one central trunk. Or you can prune to just a few central trunks, understanding that the tree will likely need additional support such as cabling or propping. Such drastic pruning should be done while the tree is still young. You may also shape the crown in later years by pruning lightly after the flowering period. Remove any dead or diseased branches as you see them, preferably in dry weather when fungi are less likely to infect pruning wounds. Do not be alarmed by a dramatically leaning saucer magnolia; instead, consider having it propped. It is common for these trees to grow with rather extreme leans.
Propagating Saucer Magnolia
Saucer magnolia is a fairly fast-growing tree that can be propagated from cuttings but be prepared for a good number of the cuttings to fail. If you start 4 to 6 cuttings, you have a good likelihood of 1 or 2 succeeding. It’s best to take cuttings in summer after the buds have set. Magnolias started this way often grow large enough to produce flowers within two to three years.
How to Grow Saucer Magnolia From Seed
Gather the seeds of the saucer magnolia during spring and summer. They need a period of dormancy, so plan to plant the seeds outdoors in the fall, about 1/4 to 1/2 inch deep. The seeds should germinate in the spring. It’s possible to germinate the seeds indoors. Use an empty coffee can or a similar container. Bury the seed in a few inches of moist peat moss, add the lid, and punch holes in the lid for air circulation. Place the can in the refrigerator for three to five months. When the time is up, remove the seed and plant it in a small container indoors. Keep the soil moist while the seed germinates. When spring rolls around, and the threat of frost has passed, plant the germinated seed outdoors to continue growth.
Overwintering
Saucer magnolia is a hardy plant that needs no particular care to overwinter well. Keep watering it through the winter if snows and rains aren’t quite enough, and add a thick layer of mulch around the trunk to protect the root system from deep cold.
Common Pests and Plant Diseases
Saucer magnolia doesn’t suffer from many severe insect or disease issues. However, it can be affected by leaf spots and canker, both caused by fungi. Copper-based fungicides regularly applied (preferably before the spots appear) can prevent fungal leaf spots. Prune away and destroy canker-damaged branches during dry weather, sterilizing the pruning shears after each cut.
Common Problems With Saucer Magnolia
Saucer magnolia is a hardy plant that presents few problems. However, fungal diseases might be an issue.
Spots, Yellowing, or Dropping Leaves
Small brown or black spots, yellowing leaves, or early leaf drops are signs of common disease leaf spot. This condition doesn’t require treatment.
Black Growth on Leaves
A black, velvety growth on leaves can indicate sooty mold. Treat this with a strong spray of water across the leaves or a 2 percent solution of horticultural oil for severe cases.
Discolored Rings on Branches
Rings on the larger branches are often the result of sapsuckers, a type of woodpecker. Wrap the branches in burlap or hardware cloth to discourage revisiting.
White Powder on Leaves
This condition is known as powdery mildew, which can make the tree drop yellowed leaves early in the season. To treat, try a solution of 1 tablespoon baking soda to 1 tablespoon of horticultural oil to 1 gallon of water, sprayed thoroughly on the foliage.
