Anita Morton - Growing Gardens
Seize the moment
Some plants never seem to pause they just keep growing and flowering, growing and flowering. Grevilleas are a prime example. Those of us who cant bear to cut off flowers will find it hard to shape and control these shrubs, as they are always in bloom.
Grevilleas have the fewest flowers about now, so harden your heart and prune. If its been a few years since you got out the loppers, your grevillea shrub may be looking more like a small tree. The good news is that even very thick wood up to 15cm across can be cut off without harming the plant. If you need to subdue an overgrown grevillea, consider cutting the entire top off about 50cm above ground level. It will look horrible for a few months, but will sprout luxuriant new foliage this summer.
Many people are quite allergic to grevilleas. If you are like me and break out in an itchy rash after contact, be sure to wear a long-sleeved shirt and gloves while pruning. Even if youre not allergic, wearing a hat and protective glasses is a good idea when working on overhead branches. Some grevilleas seem to retain a lot of old leaves in the crown, and this rains down when you prune.
Pruning rejuvenates grevilleas, and should really be done twice a year now, and in autumn. Grevilleas will live much longer and will be better garden plants if you follow this regime. A very old and neglected shrub can possibly be renovated by the radical method described above, but could also respond by dying. This is no real loss, as such a shrub has a limited life ahead anyway. Whip out the stump and plant a healthy replacement and resolve to get out the secateurs twice a year to keep it that way.