Is it in a container and how long if it has. The size of the pot and plant would help also.

Members of the pea family often struggle in pots and will start aborting leaves, twigs and even branches if they become too root bound.....

Acacia Dealbata grow into BIG Trees eventually. I grew mine from seed and at four feet its doing well. You need to plant it in a sheltered part of the garden, well away from the house and give it plenty of room as it grows. It is a handsome tree but needs lots of room as it matures. Its not that fussy on loam but needs to be kept where frost is not going to affect it much (don't plant in a hollow or valley) if temperatures get down to -10c regularly - though some trees grow high up on the hills in Wales and don't seem to suffer from their situ. Where you site it needs careful consideration as it will eventually overshadow the house and its roots will damage its foundations. Get it out of the pot or tub as soon as you can!