Fertiliser use after establishment
Apply fertilisers after establishment? Generally; no. Apply more if growth seems to be less than you think it should be, but be aware that some other part of the environment (too cold; not humid enough, too shady…) might be the cause of the poor growth. You might also apply a bit more fertiliser if you want rapid coverage of a trellis by a creeper. Otherwise, applying more fertiliser will probably just mean more work for you in hacking back over - exuberant growth created by ample water plus ample nutrition.
This recommendation assumes that you applied some organic mulch to the area after planting, and that you leave all of the shed leaves and twigs to add to that mulch. Recycling of nutrients from the mulch will provide all the ongoing nutrition your plants need – just like in the bush. This recycling will be particularly useful if you have included some leguminous plants in your garden. Their leaves are much richer in nitrogen than are the leaves of non-legumes.