Summer Red flowering gum

Sun

Full sun; choose a warm position sheltered from cold, drying winds.

Water

Water deeply during establishment and during prolonged dry spells. Established trees tolerate some drought but flower and grow better with occasional deep watering in hot, dry weather.

Soil

Well-drained sandy or loamy soil, preferably slightly acidic to neutral. Avoid waterlogged ground and strongly alkaline soil.

Height

16-20 ft (5-6 m)

Spread

10-16 ft (3-5 m)

Flowers

Summer; large clusters of pinkish-red to red flowers with conspicuous stamens.

Foliage

Evergreen, broad, leathery green leaves, often with reddish or bronze new growth.

Growth

Moderate to fast in warm conditions with adequate moisture.

Care needed

Medium

• Pollinators
• Drought tolerant
• Heat tolerant
• Wildlife

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

Difficulty

Hard

Toughness

Needs looking after

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

1. Planting day

   7 ft (2 m)

2. After 1 year

   7 ft (2.2 m)

3. After 2 years

   8 ft (2.4 m)

4. After 3 years

   9 ft (2.7 m)

5. After 5 years

   10 ft (3.1 m)

About 16 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

Toxic

Growth rate

Fast

• Water the root ball and surrounding soil deeply through the first two growing seasons; let the surface begin to dry between waterings.
• Apply a low-phosphorus fertiliser suitable for Australian native plants in spring, following the label rate.
• Spread organic mulch over the root zone, keeping it clear of the trunk and graft union.
• Remove shoots arising below the graft union promptly; these belong to the rootstock.
• Protect young trees from frost and strong winds; do not rely on frost cloth to make this a cold-climate tree.

Pruning. Lightly prune after flowering to shorten wayward shoots and develop a balanced crown while the tree is young. Remove dead or damaged branches as needed, but avoid topping or cutting hard into old wood.

Spring

Plant once frost risk has passed and the soil is warming; water thoroughly.

Spring

Apply low-phosphorus fertiliser if needed and refresh mulch without covering the trunk.

Summer

Check soil moisture during hot spells and water deeply rather than giving frequent shallow drinks.

Late summer

After flowering, lightly shape young trees and remove accessible spent flower clusters if desired.

Autumn

Check the graft union and remove any rootstock shoots; check that stakes or ties are not rubbing.

Winter

Protect young trees during forecast frosts and ensure water drains freely around the roots.

• Use as a flowering specimen in a sunny lawn or broad planting bed, allowing room for its mature crown.
• Combine with grevilleas, westringias and lomandras in a warm-climate Australian native garden.
• Place beyond a terrace to provide summer colour and light shade, keeping falling flowers and woody capsules away from main walking routes.
• Use as a small canopy tree above drought-tolerant grasses and shrubs in a contemporary garden.

Garden styles it suits: Australian native, Modern, Architectural minimal, Wildlife garden, Pollinator garden and Mediterranean.

Plant it with: Lomandra, Kangaroo paw, Coastal rosemary, Grevillea, Flax lily and Bottlebrush.

Wildlife: Nectar-rich flowers attract bees and nectar-feeding birds, including honeyeaters and lorikeets in Australia. The canopy also provides shelter for small birds.

• Root rot in wet soil: improve drainage before planting and avoid sites that remain saturated; do not keep watering already-wet soil.
• Frost damage: choose a frost-sheltered position and protect young trees; wait until spring growth begins before removing damaged shoots.
• Rootstock suckers: remove shoots below the graft promptly so they do not overtake the flowering cultivar.
• Scale insects and associated sooty mould: inspect stems and leaves, manage ants, and treat accessible infestations with a labelled horticultural oil when temperatures are mild.

Treat the leaves and their aromatic oils as toxic if eaten by cats, dogs, horses or people. Specific toxicity data for this hybrid are limited, but eucalyptus-type foliage can cause digestive upset and more serious poisoning; concentrated essential oil is particularly dangerous. Do not use the leaves for tea or animal feed.

• Summer Beauty flowering gum (Corymbia 'Summer Beauty')

  A closely related hybrid with a similar habit and foliage, but flowers are generally soft pink rather than the stronger pinkish-red of 'Summer Red'.

• Red flowering gum (Corymbia ficifolia)

  Very similar in leaf and flower; seed-grown trees vary widely in flower colour and size. Appearance alone may not establish identity, so check the nursery label and graft history.

Corymbia refers to the corymb-like arrangement of its flower clusters, while 'Summer Red' describes the flowering season and colour.

Propagation. Usually propagated commercially by grafting onto compatible seedling rootstock. Seed does not reproduce 'Summer Red' reliably, and home propagation from cuttings is difficult; buy a labelled grafted tree.

Accepted botanical name

Corymbia

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