Saucer magnolia
Magnolia × soulangeana (M. denudata × M. liliiflora) · Magnolia family (Magnoliaceae)
| Hardiness zones | 4 to 9 |
|---|---|
| Sun | full sun to part shade |
| Water | moderate |
| Life cycle | perennial |
| Frost | Hardy: takes frost |
About Saucer magnolia
Saucer magnolia is a hybrid small tree or large shrub that covers its bare branches with big cup-shaped flowers, pink-purple outside and white inside, from late winter to mid spring. Its main drawback is that late frosts often brown the open flowers, so late-blooming cultivars and a sheltered spot help.
Zones 4-9 (NC State); in frost-prone areas choose late-flowering cultivars.
When to plant
Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.
Plant container or balled-and-burlapped trees. Container trees can go in any time the ground can be worked, but fall is the best season in the South because roots keep growing through mild weather (Clemson). Dig the hole no deeper than the root ball and at least twice as wide, keep the top roots level with the soil, and mulch 2-4 inches without touching the trunk. Give its fleshy roots plenty of room. Choose a site out of strong wind and away from hot south walls, which push buds open early into frost (NC State).
Soil
Well-drained, acidic, loamy soil high in organic matter, kept evenly moist (NC State).
Test the soil first. Loosen a wide planting area and mix 10-20 percent compost into the native soil you dig out; don't use uncomposted bark, and don't dig deeper than the root ball (Clemson).
Feeding
- Spring to early summer, after the tree is established, and only if a soil test or pale leaves and weak twig growth show a need: slow-release nitrogen fertilizer with a ratio near 3-1-1 or 3-1-2 (3-0-1 or 3-0-2 if the soil test shows enough phosphorus). Spread it evenly from just outside the trunk flare to the dripline and water it in. Clemson cites 2-4 lb of slow-release nitrogen per 1,000 sq ft per year, split into a spring and a late-summer feeding; follow your soil test.
First-year watering matters far more than fertilizer: water daily for the first 1-2 weeks, every 2-3 days until week 12, then weekly, using about 1-1.5 gallons per inch of trunk diameter, until the tree is established, roughly 1.5 years per inch of trunk (UMN). Don't count on rain unless it was over an inch. Keep soil evenly moist, and don't plant against a hot south wall, which opens buds early into frost (NC State). Too much fertilizer can burn roots and push soft growth that pests and cold injure (Clemson).
Harvest
Flowers open from late winter to mid spring, before the leaves; no deadheading needed. Flower buds are set the year before (NC State).
Varieties (2)
NC State names only a few late-flowering cultivars to dodge spring frost; few others are documented in extension sources we opened.
| Variety | Type | Days | Notes |
|---|---|---|---|
| Ann Betty | Late-flowering | Blooms later, so flowers are less likely to be frosted. | |
| Ballerina | Late-flowering | Blooms later, so flowers are less likely to be frosted. |
Pests to watch for
Magnolia scale, Scale insects
Diseases and problems
Sooty mold, Leaf spot, Canker, Frost injury, Drought stress
In the kitchen
Pets: Not on the ASPCA's toxic plant list for dogs.
Sources
Photo: Photo: James F. / Wikimedia Commons, CC BY 1.0 (CC BY 1.0). Photo resized for the web.
Planting dates and advice are general guidance; check with your local Cooperative Extension office for your area.