Square-fruited Grey Gum Plant Care
Eucalyptus quadrangulata Deane & Maiden
Updated · Sources · How we source care data
Eucalyptus quadrangulata, commonly known as the white-topped box or coast white box, is a species of small to medium-sized tree that is endemic to eastern Australia. It has rough, fibrous or flaky bark on the trunk and branches, lance-shaped to curved adult leaves, flower buds in groups of seven, white flowers and conical fruit.
Every 7–14 days
Full sun
50–85°F
40–70%
At a glance
How do you care for Square-fruited Grey Gum?
Plant Square-fruited Grey Gum in full sun (USDA zones 12a) and water a young tree every 7–14 days until it is established. It tolerates temperatures of 50–85°F (10–29°C). Fertilize it every 6 months during the growing season. It is reported as toxic to pets, so keep it out of reach of pets.
Where Is the Square-fruited Grey Gum Native To?
What Is the Square-fruited Grey Gum?
Square-fruited Grey Gum (Eucalyptus quadrangulata) belongs to the Myrtaceae family within the Eucalyptus genus. Square-fruited Grey Gum is native to eastern Australia. Square-fruited Grey Gum is also known as Square-fruited Gum.
Square-fruited Grey Gum displays a fast-growing tall tree growth habit, reaching up to 100 ft tall with a spread of approximately 50 ft. Square-fruited Grey Gum produces small white, cream, or pink flowers in clusters.
Leaf size: approximately 6 inches.
How Often Should You Water a Square-fruited Grey Gum?
Water a young or newly planted Square-fruited Grey Gum every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–14 days
Until established; then in dry spells
What Light Does the Square-fruited Grey Gum Need?
Square-fruited Grey Gum thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Square-fruited Grey Gum Prefer?
Eucalyptus quadrangulata tolerates temperatures of 50–85°F. Square-fruited Grey Gum prefers humidity levels of 40–70%.
Temperature
50–85°F
Humidity
40–70%
What Soil Mix Works Best for a Square-fruited Grey Gum?
Well-draining sandy loam with some organic matter. Good drainage is essential for Square-fruited Grey Gum to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Square-fruited Grey Gum?
Feed Square-fruited Grey Gum every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.
Stop feeding by late summer so new growth can harden before winter.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
Where Should You Plant a Square-fruited Grey Gum?
Choose a spot with full sun and well-draining sandy loam with some organic matter. Avoid low spots where water collects after rain.
Square-fruited Grey Gum is suited to USDA Zone 12a.
Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a Square-fruited Grey Gum?
Square-fruited Grey Gum can spread to about 50 ft (15.2 m) and reach about 100 ft (30 m) tall. Space plants about 50 ft (15.2 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the tree spacing calculator.
How Do You Prune a Square-fruited Grey Gum?
Prune Square-fruited Grey Gum while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.
How Do You Care for a Square-fruited Grey Gum in Winter?
Square-fruited Grey Gum is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.
How Do You Propagate a Square-fruited Grey Gum?
Square-fruited Grey Gum can be propagated through seeds, cuttings. Similar propagation techniques also apply to silver dollar eucalyptus plant care, which shares the same genus.
Is the Square-fruited Grey Gum Toxic to Pets and Children?
Toxic (caution)
Reported as toxic in our plant data. Not verified by the ASPCA.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Square-fruited Grey Gum?
Square-fruited Grey Gum is susceptible to lerp psyllids, eucalyptus gall wasp. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Square-fruited Grey Gum Need?
Square-fruited Grey Gum grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Square-fruited Grey Gum is native to eastern Australia. In cooler regions, grow Square-fruited Grey Gum as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Square-fruited Grey Gum is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Eucalyptus genus — compare its care with other Eucalyptus species on PlantoScan.
Eucalyptus is part of the Myrtaceae plant family — browse all Myrtaceae genera and species.
Square-fruited Grey Gum thrives in bright light and direct sun — see other bright-light plants.
More Eucalyptus Species
Other Eucalyptus species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Eucalyptus quadrangulata Deane & Maiden, family Myrtaceae (first published in Proc. Linn. Soc. New South Wales 24: 451 (1899)) — World Flora Online record, IPNI name record.
- Pet toxicity: Square-fruited Grey Gum is reported as toxic to pets in our plant data (not verified by the ASPCA), so treat it with caution. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Hardiness zone: USDA Zone 12a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
