HAVE several grevillea shrubs in my garden that are starting to
get leggy. I've heard they can die if you prune them the wrong way.
What should I do?
grevilleas are relatively shortlived at the best of times and don't
respond well to hard pruning - they sometimes simply won't regrow
and eventually die.
The best treatment is
to trim them lightly but frequently. Don't cut back to hard wood
with no leaves - always leave plenty of foliage cover. A light trim
several times a year is best. Ideally, start trimming right from
when you plant them to encourage a bushy shape, then after each
flush of flowers. Wear gloves, as some people come down with a nasty
rash if they come in contact with grevillea sap. And don't feed
them in the hope of encouraging lots of growth. Like proteas and
leucadendrons, grevillea roots are very sensitive to excess fertiliser,
particularly those containing phosphates, which most general fertilisers
do. Unless they look really starved, don't feed them at all and
then only use fertilisers specifically formulated for phosphoroussensitive
plants, such as Osmocote Native Gardens.
Gardener, Issue 149, 2004, Page 26
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.