One of the unfortunate myths that have grown up around Australian plants is that somehow they should not be pruned on a regular basis, if at all. It is important to challenge this if your native plants are to achieve what you want them to in your garden. There should be no hard and fast rules when it comes to this subject because it depends very much on what you are trying to do with your plants. For instance, you may want a formal hedge or an informal screen or indeed just a nice compact free flowering specimen.
There are several types of pruning that will be of benefit to various Australian plants:
1. Tip pruning involves pinching out the soft tips at the ends of actively growing shoots. This is easily done between finger and thumb as you move around the garden and is particularly beneficial to newly planted specimens of virtually every plant in the garden with the exception of plants where a single ‘leader’ shoot is desirable such as a Bunya or Hoop Pine.
The more tip pruning you do the more branches you will have and for flowering plants, this means a more spectacular display later in life.
2. Annual maintenance pruning involves pruning a plant after it has flowered or fruited. Generally this is done straight after flowering or fruiting has finished which often occurs in spring or summer. Cut back shoots to just behind the spent flowers or fruits and it is usually advisable to feed and water the plant at the same time to encourage a new flush of vegetative growth.
3. Hedge and topiary pruning is used to create very formal shapes in the garden and requires shaping of the plant from an early age and also involves regular trimming to keep the desired shape once it has been achieved. Generally speaking a hedge or topiary will need to be trimmed at least every couple of months through spring and summer to achieve a high quality result. Small leaved species that are tough plants such as various cultivars of lilly pilly (Acmena and Syzygium) Westringia, Grevillea and Callistemon all make good choices.
4. Renovation pruning is used to cut hard into an overgrown plant that would otherwise be pulled out. A wide range of Australian plants will respond to this rather harsh treatment in the same way they respond to major bushfires where the top of the plant is usually burnt to the stump. Species that have a lignotuber such as the waratah, many banksias and eucalypts will readily regrow from pruning the plant to the ground.
The bottom line is do not be afraid to prune your Australian native plants. Treating them in the same way you would your roses, gardenias and camellias will reward you with more compact and more floriferous plants in your garden.