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Products > Eucalyptus erythrocorys
Eucalyptus erythrocorys - Red-cap Gum

Note: This plant is not currently for sale. This is an archive page preserved for informational use.  
Image of Eucalyptus erythrocorys
[2nd Image]
Habit and Cultural Information
Category: Tree
Family: Myrtaceae (Myrtles)
Origin: Australia (Australasia)
Evergreen: Yes
Flower Color: Yellow
Bloomtime: Fall/Spring
Height: 15-25 feet
Width: 8-10 feet
Exposure: Full Sun
Seaside: Yes
Summer Dry: Yes
Deer Tolerant: Yes
Irrigation (H2O Info): Medium Water Needs
Winter Hardiness: 25-30 F
Eucalyptus erythrocorys (Red-cap Gum) - This moderately fast growing plant is a small evergreen tree or large shrub typically grows to 15 to 25+ feet tall and spreads to 10 to 20 feet wide, usually with low branching and a fairly open canopy. It has an attractive smooth creamy white trunk with rough patches of brown bark and 6 to 10 inch long aromatic lanceolate to sickle shaped green leaves with red petioles. The flower buds that form in the leaf axils are in groups of three with a flattened four lobed bright red operculum (cap) that is pushed partially off by the bright yellow stamens, which are held in four distinct bundles in the corners of the flower base, the capsule or "gum nut". The main flowering period of Red-cap Gum occurs from late summer through early spring but flowers, which are and amazing 2 to 3 inches wide, are often seen here at other times of the year. Unusual for a Eucalyptus, the operculum remains partially attached, so for a time both the red caps of open flowers and buds still unopened, together with the contrasting yellow stamens of open flowers, provide a showy display. Plant in full sun in a well-drained soil or heavy soil where it is quite drought tolerant once established but can also tolerate regular water so long as the soil drains. This adaptable plant grows well along the coast, is desert heat tolerant, has proven hardy to short duration temperatures down to 23F and, since it comes from areas with limestone soils, it has also show to be well adapted to alkaline conditions. Red Cap Gum however is prone to breaking from the weight of the large developed fruit, so occasional light pruning to reduce weight and to shape the plant is recommended. This showy plant is great in the garden and can be grown in large containers. It buds and flowers are also quite useful in floral displays and the open flowers are also enjoyed by hummingbirds and other nectar feeders. The type locality of this plant first described in 1860 was from a plant discovered along the Murchison River, north of Perth. It is typically found growing limestone ridges, outcrops sandy alkaline soils from Dongara north to the sand plains around Shark Bay. The name for the genus comes from the Greek words 'eu' meaning "well" and 'kalypto' meaning 'to cover' as with a lid and an allusion to the united calyx-lobes and petals that is called an operculum that forms a lid or cap that is shed when the flowers open. The specific epithet is from the Greek words 'erythro' meaning "red" and 'korys' meaning "helmet" in reference to the bright red cap. Other common names include Helmet Nut Gum and Illyarrie, which is the indigenous Noongar Aboriginal Australian peoples name for the plant. We first grew this plant from 1982 until 1996 and have a specimen from these days on the nursery grounds that flowers well and gets asked about regularly because of its showy flowers. In 2020 we have decided again to grow a small crop of this plant for those who love these small showy gums.  The information about Eucalyptus erythrocorys displayed on this page is based on research conducted in our nursery library and from online sources we consider reliable. We will also relate those observations made of this plant as it grows in our nursery gardens and in other gardens that we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone who has additional information, particularly when they share cultural information that would aid others in growing it.