Planting behind retaining wall

We have a HUGE 3m backyard & have a retaining wall 150mm in from the boundary and it seems a bit of a waste between the retaining wall & the fence. Natural ground level is lower. Is there anything we could plant behind there to green things up a bit?

If you want something to cover the fence, perhaps some climbing plants? Lots to choose from there - Chinese star jasmine, wonga vine, clematis, just to mention a few. Or some ground covers can cascade down your wall, which is a lovely effect. There are a few ideas here.

Large shrubs that will develop big root systems are probably best avoided.

You could also put a row of plants in attractive pots on top of the retaining wall. I've seen this done really well, but can't find a photos just at the moment. 150mm is probably a bit too narrow for anything substantial though.

Your other alternative is to plant some taller species at the base of your retaining wall, so they'll grow upwards and screen off the wall and fence.

Folks a great newish plant variety in nurseries is this Casuarina called "cousin it" Not a tree like most would know 10cm high by 1m wide so excellent for on top of retaining walls but also in replacing turf in verges and front yards.