Coolibah
Eucalyptus microtheca
A tough Australian shade tree that thrives on minimal water, providing a broad canopy in the hottest desert conditions.
Tough to about 15-18°F with excellent heat tolerance, suited to low and mid desert.
AMWUA Notes
Very low water use; among the most heat- and drought-tough shade trees available.
Care Guide
Deep-soak every 3-4 weeks in summer once established; extremely drought tolerant with deep infrequent watering.
Train to a single leader when young and thin the canopy to reduce wind resistance; prune in late winter.
No fertilizer needed.
Few problems; lerp psyllids are possible.
Cream flowers in summer; evergreen gray-green foliage that sheds bark, leaves, and capsules.
Soil, Feeding & Propagation
Adaptable, well-draining native soil; tolerates caliche, clay, alkaline pH, and periodic flooding in habitat
Needs moderate soil.
Low feeder.
Grown from fine seed sown on the surface; not from cuttings
20–25 ft
Vigorous roots seek water and can lift paving; keep 20 ft from pools, foundations, and sewer lines
Placement Tips
- •Large 25 ft canopy for big-lot shade; keep 15+ ft from pools because it sheds bark, leaves, and seed capsules.
- •Give it 20 ft of clearance from structures and thin the canopy so it stays wind-firm.
- •A rugged choice for the hottest, most exposed sites.
- •Full sun; needs room to reach its broad mature size.
Features
Best Uses
Companion Plants
Quick Stats
Design Styles
Include in Your Project
Love Coolibah? Our landscape team sources from wholesale nurseries and can incorporate it into your design.
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Use this care guide to maintain your Coolibah. Questions about your landscape? Reach out anytime.
Data from 2024 AMWUA “Landscape Plants for the Arizona Desert” guide.
Coolibah — common questions
Answers for low-desert Phoenix conditions, drawn from this plant’s growing data.
How much water does Coolibah need in Phoenix?
Coolibah is a very low-water tree once established. Deep-soak every 3-4 weeks in summer once established; extremely drought tolerant with deep infrequent watering. Very low water use; among the most heat- and drought-tough shade trees available.
How big does Coolibah get?
Expect roughly 35 ft tall and 25 ft wide at maturity, with a moderate growth rate. Allow about 20–25 ft of spacing when planting. Vigorous roots seek water and can lift paving; keep 20 ft from pools, foundations, and sewer lines.
Can you plant Coolibah near a pool?
Yes. Coolibah is considered pool-friendly, meaning it stays clean enough around water features and hardscape. Litter is rated moderate.
Can Coolibah handle Arizona heat and winter frost?
Coolibah is hardy in USDA 9-11 and wants full sun. Tough to about 15-18°F with excellent heat tolerance, suited to low and mid desert. Cream flowers in summer; evergreen gray-green foliage that sheds bark, leaves, and capsules.
Does Coolibah have thorns?
No. Coolibah is thornless, so it is safe alongside walkways, patios and play areas.
Is Coolibah safe around pets?
Coolibah is listed as pet-friendly in this guide. If your dog is a determined chewer, check any new plant with your vet before planting.
When does Coolibah bloom in Arizona?
Coolibah blooms in summer, with cream flowers.
How much maintenance does Coolibah need?
Coolibah is moderate-maintenance. Leaf, flower and pod litter is rated moderate. Train to a single leader when young and thin the canopy to reduce wind resistance; prune in late winter.
What kind of soil does Coolibah need?
Adaptable, well-draining native soil; tolerates caliche, clay, alkaline pH, and periodic flooding in habitat. Nutrient needs are low. No fertilizer needed.
Is Coolibah native to Arizona?
No. Coolibah is not an Arizona native; it originates from the Australia, but it is grown successfully in low-desert landscapes here.