HAVE a problem with bamboo spreading in an established garden that
I have recently inherited. So I have three questions. Can bamboo
clumps be contained? How can I completely eradicate it from some
areas? And is it possible to kill the bamboo without harming nearby
established camellias and native bush?
are basically two types of bamboo - running and clumping. The running
varieties cause the most problems as they spread over quite large
areas once established, even under concrete paths and fences. Clumping
types also spread but are much more restrained, rather like a clump
of native flax, and they're the best types to choose for a garden.
To contain running types try the following:
- If practical, mow
closely around the clump. This way you'll cut off new shoots as
they emerge from the ground and restrict spread.
- Dig a trench all
round the clump at least 50-60cm deep and 30cm wide. In clay soil
you may get away with a shallower trench. Rhizomes are generally
in the upper layer of soil so they should grow out into the trench
where you can simply cut them off. Keep the trench open all year
round, especially in autumn when rhizome growth is at its peak.
Or line the wall of the trench with a barrier, such as concrete
or galvanised steel, and replace the soil - but watch out for
rhizomes sneaking over the top or breaking through.
To eradicate bamboo you
have two options:
- Dig out the entire
clump. This can be an almost impossible task to attempt by hand.
You may need a digger for a large clump. Make sure you get all
the rhizomes out or they could regrow.
- The easier option
is to use the herbicide Amitrole or Activated Amitrole. The best
approach is to cut all the bamboo stems down to the ground, wait
until there's lots of fresh new growth coming through then spray
when it's around a metre high, ideally in spring or autumn when
growth is vigorous. It will take several weeks to have an effect
and you may have to spray again periodically for the next two
or three years to kill it off completely. Both products are safe
to use around your established camellias and natives as long as
you don't get any spray on their foliage.
Gardener, Issue 144, 2004, Page 26
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.