Saucer Magnolia (Magnolia x soulangeana)

Saucer Magnolia

Magnolia Soulangeana, commonly known as Saucer Magnolia is a bushy, deciduous shrub or small tree which has ovate mid green leaves across long branches. In the months of April and May the Magnolia Soulangeana will bloom beautiful, goblet shaped flowers which are a variety of colours; pink, purple and white which create a stunning display across the plant. Often planted and grown in flower beds and borders and informal or cottage style gardens. Making a good garden plant in almost any, if not all planting locations and garden types.

I. Appearance and Characteristics 

Magnolia × soulangeana (Magnolia denudata × Magnolia liliiflora), the saucer magnolia or sometimes the tulip tree, is a hybrid flowering plant in the genus Magnolia and family Magnoliaceae. It is a deciduous tree with large, early-blooming flowers in various shades of white, pink, and purple. It is one of the most commonly used magnolias in horticulture, being widely planted in the British Isles, especially in the south of England; and in the United States, especially the east and west coasts.

Magnolia × soulangeana was initially bred by French plantsman Étienne Soulange-Bodin (1774–1846), a retired cavalry officer in Napoleon’s army, at his château de Fromont near Paris. He crossed Magnolia denudata with M. liliiflora in 1820, and was impressed with the resulting progeny’s first precocious flowering in 1826.

Growing as a multistemmed large shrub or small tree, Magnolia × soulangeana has alternate, simple, shiny, dark green oval-shaped leaves on stout stems. Its flowers emerge dramatically on a bare tree in early spring, with the deciduous leaves expanding shortly thereafter, lasting through summer until autumn.

Magnolia × soulangeana flowers are large, commonly 10–20 cm (4–8 in) across, and colored various shades of white, pink, and maroon. An American variety, ‘Grace McDade’ from Alabama, is reported to bear the largest flowers, with a 35 cm (14 in) diameter, white tinged with pinkish-purple. Another variety, Magnolia × soulangeana ‘Jurmag1’, is supposed to have the darkest and lightest flowers. The exact timing and length of flowering varies between named varieties, as does the shape of the flower. Some are globular, others a cup-and-saucer shape.

II. How to Grow and Care

Saucer magnolias are relatively low-maintenance trees. However, they do require some care to ensure that they thrive. Here are a few tips on how to care for your saucer magnolia tree:

Sunlight

Saucer magnolia trees prefer full sun, but they can tolerate partial shade locations.

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.1 If possible, avoid splashing soil from the ground onto the plants, and give them good air circulation.

Watering

Saucer magnolias need regular watering, especially when they are young, but allow the soil to dry out slightly between watering. Once established, they are relatively drought tolerant. However, during periods of extended drought-like summertime in Dallas, TX, you may need to water your tree more frequently.

Soil

The ideal soil for a saucer magnolia is rich, loamy, and well-drained. Avoid planting in clay or sandy soil, as this can cause the roots to suffer.

Fertilizing

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. For the amount to use, follow product label instructions.

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.

If you are like most homeowners and acquired your saucer magnolia from the previous property owner rather than by planting your own sapling, early pruning won’t be possible. Do not prune adult trees as you would a sapling. Only remove dead and damaged limbs. Call a certified arborist as needed.

Propagation

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 with four to six cuttings, there’s a good likelihood that one or two of them will succeed. It’s best to take cuttings in summer after the buds have set. Take these steps:

  • Use a sterilized, sharp knife or pruning shears to cut a 6- to 9-inch cutting from the tip of a branch. Immediately place the cutting into water to keep it moist.
  • Remove all but the upper leaves, then make a 2-inch vertical slice at the end of the stem.
  • Dip the stem into a rooting hormone, then place the tip of the cutting into a planter filled with moist perlite.
  • Place the cutting in indirect light and cover it loosely with a plastic bag to keep the cutting in humid conditions. Mist the cutting often and watch for roots to grow.
  • When a good network of roots has developed, transfer the plant to a larger pot filled with potting mix for continued growth. The magnolia can be planted in the landscape when vigorous upper growth has begun.

How to Grow from Seed

It’s possible to grow saucer magnolia from seed. Here’s how:

  • 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 in a sunny or slightly shady spot 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.

Pests and Diseases

Common Pests & 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.3 This condition doesn’t require treatment.

Phytophthora root rot could be another possible cause of yellowing or wilting leaves and often affects a tree when the soil around the base has been wet for long periods. As the leaves begin to show symptoms, the inside of the tree trunk is becoming wet and damaged, which is why good soil drainage or planting trees in mounds is essential. Unfortunately, once symptoms occur the tree’s poor prognosis is certain though the decline could be slow.

Black Growth on Leaves

A black, velvety growth on leaves can indicate sooty mold.4 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.2 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.3 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.

Damaged Bark

The smooth bark of a saucer magnolia is thin and it can easily be nicked by a lawnmower or other garden tool. Damaged bark can let in disease and pests so it’s very important to be careful when doing landscape maintenance. If the damage is done and is severe, you may need to protect the wounds with tree wrap. A professional arborist can better assess the damage.

III. Uses and Benefits 

It has multiple uses in the landscape, including as a specimen or accent tree due to its outstanding floral display. It creates an impressive scene in the garden and is an excellent selection as a container plant and espalier.

The large logs can be of use for manufacturing machines for cabinet or millwork. Or the wood has also been used for making paper.

Saucer Magnolia (Magnolia x soulangeana) Details

Common name Saucer Magnolia
Botanical name Magnolia x soulangeana
Plant type Perennial
Hardiness zone 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Medium
Harvest time Fall
Height 15 ft. 0 in. - 33 ft. 0 in.
Width 15 ft. 0 in. - 33 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition High Organic Matter
Flower color Pink
Leaf color Green