Hi @kayara,
When your hedge is still establishing, the best approach is to encourage branching rather than just trimming the surface. You can do this through tip pruning, which simply means lightly trimming off the ends of each shoot with some clean, sharp secateurs; just a few centimetres is enough. This encourages the plant to produce multiple new shoots from just below each cut, helping it thicken up from the inside rather than just growing taller.
Once the hedge is roughly at your desired height and starting to take shape, you can switch to using a hedge trimmer to maintain an even shape. When doing this, try to trim lightly and often. Several small trims through the growing season are better than one heavy cut.
After pruning, it’s a good idea to feed the plants with a slow-release fertiliser formulated for natives such as this Scotts Osmocote Native Controlled Release Fertiliser. Follow up with a deep watering to keep the roots moist and healthy.
Check out How To Trim Hedges for some further guidance.
Let me know if you have any further questions.
Jacob
