Magnolia 'Susan'

Sun

Full sun to partial shade; flowering is best with plenty of sun. Afternoon shade helps in hot climates.

Water

Keep the root zone evenly moist but not waterlogged, especially during the first two growing seasons and in summer drought.

Soil

Moist, well-drained, humus-rich soil, preferably acidic to neutral. Avoid strongly alkaline soil and ground that stays waterlogged.

Height

8-12 ft (2.4-3.7 m)

Spread

8-12 ft (2.4-3.7 m)

Flowers

Mid- to late spring; upright, narrow-petalled flowers are reddish-purple outside and paler pink inside. Occasional scattered flowers may follow in summer.

Foliage

Broad, oval, medium- to dark-green leaves; autumn colour is usually yellow-brown and not especially showy.

Growth

Slow to moderate.

Care needed

Low

• Pollinators
• Cold hardy
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2.9 ft (0.89 m)

3. After 2 years

   4 ft (1.3 m)

4. After 3 years

   6 ft (1.7 m)

5. After 5 years

   8 ft (2.5 m)

About 7 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Slow

• Plant with the root flare at soil level in a sheltered position, away from frost pockets and drying winds.
• Water deeply during dry spells for the first two growing seasons; water established plants during prolonged drought.
• Apply 2-3 in (5-8 cm) of leaf mould or composted bark over the root zone, keeping it clear of the stems.
• Avoid digging beneath the canopy, where shallow, fleshy roots are easily damaged.
• Feed lightly in spring only if growth is weak or a soil test shows a deficiency; avoid heavy nitrogen feeding.

Pruning. Prune only when necessary, just after flowering, removing dead, damaged or crossing branches. Avoid hard pruning and large cuts, which spoil the natural shape and heal slowly.

Early spring

Check soil moisture and apply a light feed only if needed.

Spring

Protect flower buds on small plants with horticultural fleece when a late frost is forecast; remove it during the day.

Late spring

After flowering, remove damaged or crossing branches if necessary.

Summer

Water deeply during prolonged dry weather and keep grass away from the root zone.

Autumn

Refresh the organic mulch without piling it against the stems.

Autumn or spring

Plant while the soil is workable; choose spring in regions with severe winters.

• Use as a spring-flowering focal point in a small lawn, with a broad mulched area beneath it.
• Place near a patio or path where the flowers can be seen closely, allowing room for its mature spread.
• Combine with rhododendrons, azaleas and ferns in a sheltered, lightly shaded border with acidic soil.
• Underplant with snowdrops and other small spring bulbs for flowers before the magnolia canopy fills out.

Garden styles it suits: English country, Cottage garden, Woodland, Japanese, Romantic rose garden and Modern courtyard.

Plant it with: Japanese maple, Rhododendron, Azalea, Hellebore, Snowdrop and Japanese painted fern.

Wildlife: Flowers offer pollen to visiting insects, including beetles. The dense branching provides shelter for small birds, although this cultivar is not a major wildlife food plant.

• Late frost can brown buds and open flowers: avoid frost pockets and cover small plants temporarily when frost is forecast.
• Yellow leaves with green veins can indicate iron deficiency in alkaline soil: test the soil, use chelated iron as a temporary correction, and avoid unsuitable chalky sites.
• Magnolia scale can cause sticky honeydew and sooty mould, particularly in North America: inspect stems and use horticultural oil or a locally recommended treatment timed to the vulnerable crawler stage.
• Waterlogged soil can cause root decline: improve drainage before planting and do not keep watering already saturated ground.

Not known to be toxic to people, cats, dogs or horses. No part is generally recognised as poisonous, but it is an ornamental rather than a food plant, and eating plant material may cause mild stomach upset.

• Jane magnolia (Magnolia 'Jane')

  'Jane' usually has a stronger contrast between its reddish-purple outer petals and near-white interiors; 'Susan' has paler pink interiors and often narrower, slightly twisted petals.

• Purple lily magnolia (Magnolia liliiflora 'Nigra')

  Its flowers are generally darker purple and more narrowly goblet-shaped; 'Susan' tends to open more widely, revealing its paler interior.

• Star magnolia (Magnolia stellata)

  Star magnolia usually flowers earlier and has many narrow, spreading white or pale-pink petals rather than the upright reddish-purple flowers of 'Susan'.

Magnolia honours the French botanist Pierre Magnol.

Propagation. Propagate by softwood cuttings in early summer or by layering; rooting can be slow and unreliable at home. Seedlings will not reliably retain the characteristics of 'Susan'.

Accepted botanical name

Magnolia

Sources: GBIF (CC BY 4.0). The care and design notes are LandscapeGPT's own.