Corymbia ficifolia aka Redflower Gum

Corymbia ficifolia belongs to the myrtle family. This evergreen tree keeps its leaves all year. It comes from southwestern Western Australia. It suits warm climates. Its common names are red-flowering gum and scarlet-flowering gum. Its older name is Eucalyptus ficifolia. It grows fast and forms a round, uneven crown. Most trees have one trunk. Their branches spread out.

Size varies with the site and climate. Florida guidance gives heights of 30–40 feet [9–12 m]. The RHS gives a wider range of 20–49 feet [6–15 m]. Spread reaches 15–25 feet [4.6–7.6 m]. The RHS records widths beyond 26 feet [8 m]. Rough bark has dark grey and brown tones. Thin young twigs can be red or brown. The simple leaves grow in an alternate pattern, taking turns along stems. Their edges are smooth. Their pinnate veins branch from a central vein. Leaves range from oval to broad and lance-shaped. They are green above and paler beneath. They do not change colour in autumn.

Large groups of flowers form near branch tips. They bloom from summer into autumn. Each group holds three to seven scarlet or flame-toned flowers. These bright blooms make the tree useful as a garden specimen. Growers also cut the flowers for indoor use. Woody seed capsules form after the blooms. These hard, urn-shaped fruits are green or brown. Florida guidance gives their length as one to three inches. It reports little litter trouble from leaves or fruit.

Give this tree full sun and shelter from wind. It needs soil that drains well. The RHS favours moist soil with an acid or neutral pH. Florida guidance also lists clay, sand, and loam. It lists slightly alkaline soil too. It rates the tree's drought tolerance as high. The tree cannot withstand freezing. The RHS rates it H2. Florida guidance lists USDA zones 9b–11. In cold areas, grow it in a bright, airy greenhouse. Water well in spring and summer. Give less water in winter. The tree suits coastal and subtropical gardens. Its salt tolerance remains uncertain.

Prune young trees to build strong branch structure. Branches can break, so a sheltered site matters. Gall wasps and eucalyptus suckers may attack. So may scales, mites, and borers. Silver leaf and oedema can cause trouble. So can powdery mildew and Phytophthora diseases. Florida guidance reports resistance to Armillaria root rot. It also reports resistance to Verticillium wilt. The supplied sources give no evidence on edibility or toxicity.