crinodendron hookerianum

Our lost just about all of its leaves and flower buds last winter due to the extended frost when it couldn't get any water but is fine now. Did you water well after planting?

It sounds as if it might be short on water, Rosy. Have you been watering it well sice you planted it?

It is if the surrounding soil's dry and if the soil its in is alkaline.
Both of those scenarios will need action.

The former means copious watering and the latter a change in position or, removing it and digging ericaceous compost into the 'large' new hole because its roots want to get nutrients from acid not alkaline soil.

I have one and the leaves do drop but they don't turn yellow.
Mine's in neutral-acid soil.