Even without the bright yellow staminate flowers (fuzzy with prominent stamens) that bloom in late summer or autumn, the grayish foliage of knife-leaf wattle, Acacia cultriformis, is still striking. It contrasts nicely with dark green foliage of pines, redwood and ivy. What seems to be small triangular leaves are actually ‘phyllodes’, which are modified petioles (leaf stalks) of vestigial leaves. They are about half an inch to an inch long, and neatly arranged on stiff stems.
Mature trees do not get much more than ten feet tall, and grow slowly enough to be kept even shorter. They can tolerate a bit of shade from larger trees. However, they bloom more profusely with better exposure. If the pollen is not a problem, the flowers are nice for cutting. So is the foliage, which is complimentary to many other cut flowers. Like almost all acacias, knife-leaf acacia does not require much water once established.