Acacia auriculiformis, commonly known as earleaf acacia or northern black wattle, is a fast-growing leguminous tree native to Australia, Papua New Guinea, and Indonesia. This multipurpose species exhibits significant seed dormancy that requires pre-treatment to achieve high germination rates. With proper pre-sowing treatments and optimal growing conditions, germination rates exceed 70-83%, making propagation relatively straightforward for experienced nursery practitioners.
Before sowing
Hot water treatment (80°C for 10 minutes) is the recommended pre-treatment for optimal germination. Without pretreatment, germination rate is only 43%. Scarification with sandpaper or sulfuric acid (5-10 minutes) are effective alternatives.
Sowing
What to expect
Tips
For best results, use hot water treatment (80°C for 10 minutes) as the primary pre-treatment method. Sow seeds on substrate surface in well-lit conditions without direct sunlight; use fluorescent lighting if necessary. Maintain high substrate moisture using transparent lids to create humid microclimate. Provide 50% shade for newly emerged seedlings, transitioning to 70% full sunlight after establishment. Seedlings reach plantable size (25 cm height) in 3-4 months. Avoid heavy clay soils; prefer well-draining sandy or loamy substrates. Store seeds in airtight containers at room temperature for extended viability (up to 18 months or several years in air-conditioned storage).
Sources: Azad et al. (2011) - Journal of Forestry Research; Pukittayacamee & Hellum (1988) - Canadian Journal of Botany; Winrock International (1996); World Agroforestry Centre; USDA Forest Service
