have a large dam/pond which is rapidly being taken over by bullrushes
(raupo?). The pond has tadpoles, ducks and freshwater crayfish in
it, so we are very cautious about spraying, but after trying to
pull them out and/or hack them down we are unsure of what to do
next. They are as rampant as bamboo. Apart from getting a digger
in to dig the pond up, can you suggest any way we could tackle this
problem? Soon the ducks will have nowhere to swim and I would prefer
lilies and irises in and around the pond.
sounds as if the dam may be shallow, as raupo is a marginal plant
and usually does not venture out into deep water. As you mentioned,
I would hesitate to use chemicals where there is a lot of marine
life and ducks. Activated Amitrole is effective on raupo, but you
would need to gather extra information about how safe it is to use
around water. I have only ever used it in the garden.
Short of pulling out
by hand, which is difficult, or digging the pond out and replanting
with marginal plants such as astilbe, gunnera, hosta, iris, lobelia
cardinalis, mimulus and primula, I cannot offer too many other suggestions.
The digger sounds like a good option to make the dam deeper.
Your local council's
noxious weeds inspector should be able to offer some advice.
by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor
of Resource Management.
with permission from NZOOM Home and Garden content,
from the previous
The views expressed here are not necessarily those of the RNZIH