Autumn is the best time to collect wattle seeds.
The seeds are released as the pods ripen, so collect the pods when they are turning brown. Remove the seeds by splitting the pods open along the seam of the pod. Wattle seeds have a very hard seed coat that has to be ruptured before the seed can absorb water and germinate. One way to break the seed coat is to soak the seeds in near-boiling water and allow to cool. Discard any floating seeds before planting.