When planting native grasses
from seed, grow-cells or advanced plants, area needs to
be:
- Free of weeds to allow the
native grass to establish - native grass seedlings
cannot compete easily against weeds. Many species are
tolerant of broadleaf herbicides once they reach about
15cm, however trial a small section first to ensure
the native grass will survive.
- Plantings require moisture until plants
have established
- 6 weeks or so for seed
- 4 weeks or so for seedlings
KANGAROO
GRASS
Themeda
australis
DESCRIPTION
Kangaroo Grass is a densely
tufted perennial with short, fine, soft, strappy leaves.
It is highly ornamental in its flowering state in
spring/summer, with green to blue-green foliage during
spring, slowly changing to purple and later to brown
during autumn and winter. It forms a large tussock
shape, if not mown, from which emerge long and graceful
tillers of flower spikes up to 1.5m, which turn a rich
golden bronze colour during late summer and
autumn.
CHOICE OF GRASS
SPECIES
- Kangaroo Grass is
probably the least site-specific of all Australian
plants, extending from arid inland to the alps
and the coast.
- Being a vigorously
growing perennial it can quickly shade many competing
weeds.
- Spring fire on a site
containing soil-stored Kangaroo Grass seed promotes
germination and temporarily reduces weed
competition.
- As a spring/summer
growing grass, tolerant to many herbicides
(chlorosulfuron, glyphosphate etc.), it is
relatively easy to establish in areas dominated by
autumn/winter growing herbs and weeds.
- It is highly tolerant of
shading by trees and shrubs.
SITE
PREPARATION
The sowing site for seed and
Grow-cell seedlings should be free of other
summer-growing grasses such as couch, paspalum, kikuyu,
nut grasses etc. If these grasses exist, then repeated
herbicide spraying at 3-4 week intervals will be needed
before sowing. Seed does not germinate readily until the
daily average temperature is at least 20 degrees C.
Being a summer-flowering species, maximum growth is
achieved by sowing in spring/summer.
CULTIVATION
Seed
sowing:
- No tilling of the site is
necessary prior to the establishment of Kangaroo
Grass, nor is the application of nutrient rich
fertilisers.
- Under optimum conditions,
seeds will germinate from 7 days to 2 weeks after
sowing.
- Seed should be
slightly buried, in order to obtain the greatest seed
to soil contact and most benefit from soil moisture.
Absence of soil contact and moisture affects the
germination of the seed.
- If soil is compacted, use
a pitchfork to aerate the soil and loosen it.
- Only a thin, maximum 1cm
layer of leaf litter or straw may be applied after
seed
planting to help the soil retain moisture. Do not
mulch the area heavily as this will prevent
germination.
- Keep area moist (water
once a day) for up to 6 weeks until you see strong
seedlings.
Hand broadcasting or
hydro-seeding is a cost effective method of establishing
Kangaroo Grass. If hydro-mulching is the method used,
great care must be taken to only spread a very thin
layer of mulch as the mulch may smother the seed if
applied too thickly.
Grow-cell
Seedlings:
Kangaroo Grass seedlings are
usually supplied in trays that contain 312 grow-cells,
each 3cm square by 5cm depth. Each cell is in the form
of an inverted pyramid for easy removal of seedlings
when planting out.
For pure dense stands
established quickly, we suggest planting Grow-cells at
10 to 15cm spacings. This will provide 50 to 100
seedlings per square metre. For mixed planting with
other native species, we suggest planting Grow-cells at
100cm spacings, giving 1 seedling per square
metre.
ESTABLISHMENT:
It is recommended that seed
or seedlings be planted in spring or early summer to
take advantage of the peak growing season. However,
seeds require a minimum of 20 deg. C to germinate and
seedlings respond to being planted out at most times of
the year.
To protect slopes from wind
or water erosion after sowing seed, a cover crop such as
Japanese millet may be hydro-seeded onto the area. The
millet binds the soil but being an annual, dies out and
allows the Kangaroo Grass to dominate and take
over.
Grow-cell seedlings should be
well watered and kept moist, water at least every day or
two, depending on weather conditions, for a period of up
to a month or so.
MANAGEMENT
Once established, Kangaroo
Grass will need no further maintenance except, very
importantly:
- An annual mowing or
slashing in winter. Alternatively, the area may be
burned every 2 to 3 years to reduce dead foliage and
encourage new growth.
- Reduce weeds in the area.
If you don’t have time to herbicide or hand weed, just
make sure you cut off any weed seed heads before they
fall. This way you will manage the land and gradually
reduce the weeds.
- Weed the area before seed
of the native grass falls. If you do not take care of
the weeds before the native grass seed falls, you will
have exotic and native grass coming up together,
something to be avoided!
These methods have proven to
be effective in producing a green cover during summer
and encourage germination of new seeds to thicken up the
area planted.
Kangaroo Grass is extremely
drought tolerant and, once established, requires no
summer watering. |
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