INVASIVE WEED SPECIES
"The fool learns by experience. The wise man learns by the
A Chinese proverb.
Plant Selection Guide
are presented of weeds in the Northern Rivers area. Gardeners should
avoid planting these species and save themselves much work having to
eradicate them from their gardens at a later stage. Even worse, the
species can become an invasive weed in the surrounding countryside.
This is particularly a problem in rural areas. There are so many
beautiful native and non-weedy exotic species to choose from. It
is very unfortunate that gardeners plant weeds, usually out of
complete ignorance of the problem they are creating.
Gardeners should learn to identify potential weeds in their area.
Early recognition is essential for quick removal of the weed species
in the early stages. A few plants are easy to get rid of. Once it
becomes firmly established, it will be impossible to eradicate and you
will just have to learn to live with the problem.
If you must plant potential weeds, there may be ways around the
* Plant seedless varieties of weed
species if they are available. The best example is a seedless form of Orange
Jessamine (Murraya paniculata). People can plant this variety and
still enjoy the perfumed flowers without creating a weed problem.
(Birds eat the fruit of this species and disperse the species widely
into the local rainforest.)
* Use the equivalent native species
where ever possible. For example, instead of planting Orange
Jessamine, use the Native Murraya (Murraya ovatifoliolata).
This way the birds can still eat the fruit and you can still
appreciate the scented flowers.
* Each year, strip the unripe
seeds from any potential small weedy tree/shrub, thereby preventing
the species from spreading. Curry Leaf (Murraya koenigi) is
weed candidate, as it suckers profusely and birds relish the fruit.
However, it can be placed in a large container and the green, unripe
fruit stripped from the tree. Make sure you do this every year.
* For species with male and female
flowers on separate plants, only use male specimens in the garden, so
seeds are never produced to create problems. One palm enthusiast
planted Chamaedorea palms in the rainforest near his house. They were
soon becoming an obvious weed with a potentially severe environmental
impact. He pulled out all the seedlings and poisoned all the female
plants. Now he can still enjoy his Chamaedoreas without any adverse
problems for his rainforest.
NB: Weedy vine species have been covered separately in Exotic
Vines: An Environmental Hazard.
The main references used in these listings were:
BFNS Environmental Weeds & Native Alternatives. A Guide to the
identification, Control & Replacement. Pamphlet by Bushland
Friendly Nursery Scheme. 2004
Noxious Weeds Guide For the North & Mid North Coast.
by the NSW North Coast Weeds Advisory Committee & the Mid North
Coast Advisory Committee. 2004.
The listings are primarily of those weed species that gardeners
are most likely to consider planting in their gardens. For more
comprehensive listings with photos, you may wish to visit the
North Coast Weeds Advisory Committee.
Association For Growing Australian Native Plants.
Flora For Fauna.
Australian Association of Bush Regenerators.
|NON WEEDY VINES
are several species of native vines that may be grown as a substitute
to exotic weedy species.
Birdwing Vine Aristolochia praevenosa
is a strong growing vine, which is the only food source for
the magnificent, endangered Richmond Birdwing Butterfly.
Planting this vine will attract these beautiful insects to
your garden or rain forest planting. NEVER PLANT the alien Dutchman’s
Pipe (Aristolochia elegans). The Birdwing Butterfly will
lay its eggs on this exotic vine, but the young caterpillars
cannot eat the leaves and die.
vine is too large and
rampant for house gardens. In rainforest regeneration plots,
they will scramble up small trees and smother them. Even so,
they should be grown where possible as they are an important
food source for various birds. Thus, they are best used for
climbing over large, established rainforest trees or
vines able to cope with harsh conditions. Attractive
trumpet-shaped, yellow flowers. In the garden, it can be used as a ground cover,
scrambling shrub or vine, depending
on support given.
attractive flowers bloom over several months. Common garden plant. Must be pruned to keep under control. Needs well drained,
attractive flowers bloom over several months. Common garden plant. May need pruning to keep under control. Drought resistant.
desirable vine to grow as it attracts various butterfly
species. It has a bushy habit and may be grown as a vine or
pruned as a shrub.
growing vine, with attractive blue flowers in
summer. Needs to be pruned regularly in garden
flowers are produced profusely, but each one only lasts only a
day. Likes plenty
of water in well drained soils.
Must have full sun for flowering and fruiting. Not a
rampant climber, making it suitable for house gardens.
attractive native vine, requiring moist, well drained soils.
Should be more widely planted.
is another rampant
vine that can be used for screening in large gardens. It will
need pruning to keep under control.
Some weed species
are so common that gardeners simply have to live with them and they
will not be commented upon: Crofton Weed (Ageratina adenophora), Mist
Flower (Ageratina riparia), Tropical Chickweed (Drymaria cordata),
& Wandering Jew (Tradescantia albiflora). The main emphasis is
given to those species that gardeners may obtain cuttings from friends
or unwittingly buy from unscrupulous nursery people.
Mother of Millions (Bryophyllum species) is a succulent
spreading herb. Flowers are quite distinctive with various colourings
- orange, yellow or red. The flower spikes are held above the foliage.
It is poisonous to livestock and should be avoided in country
Apple mint (Mentha rotundifolia) can quickly invade your garden
and should not be planted. Other Mentha species are far more useful in
cooking and are not so invasive.
Freckle Face (Protasparagus aethiopicus) is a pretty herb with
purplish leaves with distinctive pink spots. The flowers are also
pinkish. Early elimination will save you the anguish of years of
Singapore Daisy (Wedelia trilobata) is a spreading groundcover,
with distinctive bright yellow flowers.
the list goes on.......