Australian Willow Wattle
Latin Name: Acacia salicina
Price range: $16.95 through $39.95
- Pot Size: 4 Inch, 1 Gallon, 5 Gallon (Local Pickup Only)
- Hardiness Zone: Zone 9, Zone 10, Zone 11
Acacia salicina is an evergreen tree from Australia with an upright trunk and long, hanging branchlets. The drooping tips give older trees a soft outline much like a willow. Its narrow, gray-green foliage is made of phyllodes, which are flattened leaf stalks that do the work of true leaves. Hanging foliage catches less of the direct midday sun, which helps the tree cope with open, sun-baked country. Small, round flower heads in cream to pale yellow appear most heavily in spring. Unlike many of the acacias, this one carries no thorns.
Plant Details
Quick Information
- Latin Name: Acacia salicina
- Plant Family: Fabaceae
- Common Names: Willow Acacia, Australian Willow, Cooba, Native Willow, Willow Wattle, Broughton Willow, Sally Wattle
- Origin / Native Range: Inland eastern and central Australia, chiefly central Queensland and western New South Wales, extending into South Australia, Victoria, and the Northern Territory
- Mature Height × Width: 25–40 ft × 15–20 ft
- Exposure Requirements: Full Sun
- Irrigation Requirements: Low
- USDA Hardiness Zones: 9–11
- Cold Hardiness: 16°F–20°F
- Bloom Time: Spring, with lighter scattered bloom at other seasons
- Bloom Color: Cream to Pale Yellow
General Information
Young willow acacias look gangly and floppy. The adult shape takes several years to appear. Each phyllode hangs 3 to 8 inches long from a dark gray-brown branchlet. As the trunk thickens, the bark develops a finely cracked, brownish surface. The crown lifts over time, and the branch tips sweep down into the curtain of foliage the tree is known for. Spring flower heads are packed with fine stamens, the slender pollen-bearing threads that give each head its fuzzy, ball-like look. Narrow pods follow. They dry to brown, then split along both seams. Inside are shiny dark seeds, each tipped with a bright red to orange aril. An aril is a fleshy attachment that draws birds, which then carry the seed away from the parent tree.
In Australia this tree keeps to inland creek beds and floodplains. Its garden behavior follows from that habitat. It handles long dry spells and hot, reflected sun off walls and pavement. Even so, it does best with deep water spaced far apart. Frequent shallow watering keeps the roots near the surface, which is risky on a tall tree that grows several feet a year. Fast growth in this genus also means fairly weak wood. Branches often rise at narrow angles and cross one another. Young trees need staking and early pruning to build a strong frame that will hold up in wind. The tree accepts sandy, loamy, and alkaline soils, as long as water drains away freely.
The strengths come with real limits. Willow acacia sheds a steady rain of phyllode litter, which is a nuisance over pools and patios. It also suckers freely, sending up new shoots from its own roots. This happens most when the tree is stressed or its roots are disturbed, and the shoots can rise well away from the trunk. That habit has a use: the spreading roots hold soil on dry banks and slopes. It has a cost too. The species has escaped cultivation and behaved as a weed in parts of its introduced range, so it is best kept away from washes and wild land. Given room, full sun, and honest early training, it repays the effort with quick shade and an outline few desert trees can match.
General Planting & Cultivation Information
Even drought-tolerant plants require regular watering until they are well established, good drainage is essential. If planting in containers, avoid pots without drainage holes.
Irrigate by watering deeply and then allowing the top several inches of soil to dry between waterings. This encourages the plant to send roots deep into the earth in search of moisture, helping it to become established, prevent root rot, build drought tolerance, and resilience to wind, heat, and cold.
The length of time between waterings will vary depending on your growing conditions and environment. Use a moisture meter for precise irrigation.
When planting, set the plant at the same depth as it was in its current container. For trees, ensure the top of the root flare is at soil level.
Young plants are vulnerable to harsh conditions, so consider growing them in larger containers until mature.
When planting in the ground, research the optimal planting season for your climate zone and protect young plants from frost.
To support establishment, consider creating a microclimate with nurse plants, shade, or wind protection. This can reduce stress, conserve soil moisture, and increase long-term success.
Protect the small, immature plants from rabbits and deer.
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