The following is taken from Jacinta Allen's report of a pruning session with Ray Brown at Illawarra Grevillea Park in February 2003. Article supplied by Dot Gallagher.
Each grevillea differs in its ability to regenerate after pruning so often it's a case of trial and error. Many grevilleas have blind shoots, buds that lie just below the surface and are so not visi ble. This makes it difficult to cut back to a node as is the normal practice with pruning and may mean having to cut back any dead branches that have not re-shot, both for aesthetic reasons and also to remove dead wood that may act as a reservoir for pathogens.
Dead wood can be cut off at any time but pruning generally takes place during the growing season usually from spring to late summer. Hard pruning in the cold months may kill the plant or render it incapable of full recovery.
Regular tip pruning can be carried out in the warmer months by cutting back current season's growth. Start regular tip pruning from the time of planting to obtain dense foliage at the base of the plant. Commencing pruning too late often causes the plant to become top heavy and it may topple. A couple of generalisations to consider are that Queensland Grevillea species often do not reliably regrow from blind shoots. Also species that grow readily from seed do not always have epicormic growth and may not respond to hard pruning.
Some cultivars such as G. 'Robyn Gordon', G. 'Superb', and G. 'Coconut Ice' can be rejuvenated by cutting back to within 10 cm of the base in November/December every year. Do not cut if weather is still cold or in later autumn or winter.
Although the Art of Pruning grevilleas remains very much in the experimental stage, if you have a plant that is not looking its best you might as well take the risk and see what happens. At worst it creates much needed space for a new plant or you may end up with a flourish of new growth and a splendid floral display.
Grevilleas, like any plant, will grow best in the right conditions and with the right treatment, so always start with:
- A healthy plant with sound root development - never root bound.
- Plant in the best possible position with 6-8 hours of direct sun.
- Always have good drainage.
- Start tip pruning from planting time and regularly thereafter.
- Prune in the warmer months on current season's growth.
- Don't prune in extreme conditions i.e. too hot, too cold, too wet.
- Prune from the outside in.
- Always undercut branches first.
- Cut on an angle to allow water to run off. Water remaining on the surface encourages fungal growth.
- Prune off dead wood at any time.
Follow these simple guidelines and your grevilleas will look even better.
From the newsletter of the Nowra Group of the Australian Plants Society, May 2004.
Australian Plants online - 2007
Association of Societies for Growing Australian Plants