The Propagation of prostrate Acacias at the Australian National Botanic Gardens
Spring visitors to the Australian National Botanic Gardens often remark on the many prostrate Acacias cascading over walls or mounds or forming extensive groundcovers. Species include Acacia baileyana prostrate form, A. cardiophylla 'Gold Lace', A. cultriformis 'Austraflora Cascade', A. dealbata 'Kambah Karpet', and A. pravissima 'Kuranga Cascade'.
These desirable species must be propagated vegatatively to maintain their prostrate character but they are often difficult to grow from cuttings. The main problem encountered is cutting leaf drop.
It has been found that cuttings of these Acacias need to retain their leaves for at least 3-4 weeks for roots to develop. A check of Botanic Gardens records showed that a range of rooting hormones and other treatments have been tried.
The results, although not conclusive, suggest the following: 1. A rooting hormone concentration of between 3g/l - 6g/l IBA with 50% ethanol carrier and 5 second dip is most effective. 2. The best time of year for taking cuttings in Canberra is autumn/winter (April - August). 3. Regular pruning of the stock plant to encourage new growth may increase strike rate.
Good luck with your attempts!
Article by Paul Carmen, ANBG (2001)