| Native grasses are often an ignored
part of the understorey when bush regeneration is being considered. However
they can be a versatile tool for landscaping, provide a good habitat
for butterflies and many small animals, can be fairly easy to propagate and
are very beautiful. On our land in Kettering, southern Tasmania, we had an
area surrounding the sullage trenches which was heavily overgrown by the
exotic grass Yorkshire Fog (Holcus lanatus). This infestation
was dense enough to inhibit any native species from re-establishing, and
was aggressively spreading. We decided to attempt to revegetate the area
with native grasses and chose Poa labillardiere as it is a
vigorous grower that enjoys rich, damp conditions. |
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Initially we used Roundup to poison an area of Holcus and after a few weeks, planted through the dead grass with tillers of Poa lab obtained by splitting up a larger plant but, although these grew well, were soon overrun by Holcus from outside the plot. We overcame the problem with a thick layer of eucalyptus mulch and as this proved so effective, and we prefer not to use herbicides if possible, we decided to try only mulching. An area of Holcus was dug up, turned leaf side down, covered with about 6 cm of pine bark and planted out with tillers and seedlings. This again proved successful, but was quite hard work in our soggy clay soil. The next idea tried was to cover the Holcus with layers of damp newspaper followed by a 6cm deep layer of eucalypt mulch. Poa lab seedlings were planted out into the damper areas and Danthonia caspitosa on a drier site. We are delighted to report that almost all the young plants have survived, even though the normally soggy area has dried out significantly during our unusually dry winter, spring and summer. Any breakthrough of Holcus is easily removed by hand weeding. Initially we have had to fence off the plots to protect them from browsers such as wallabies, rabbits and native hens who tend to pull out the small plants by the roots, but once the plants become established the fences can be removed. We have found both Poa and Danthonia easy to raise from seed by sprinkling a layer of seed on the surface of potting mix and keeping damp. Germination usually occurs in 10 - 14 days. The seedlings are pricked out in groups of 5 - 10 and potted on until they appear to have developed a good root system and then planted out. Although Danthonia grows in dry sites, they usually need a little water if they are to survive a first dry summer. We have tried potting them on into cardboard milk containers then planting them out in the containers (after removing the bottom), and this seems to ensure that any water applied concentrates on the roots. We are now preparing a drier area of the block and will try a similar experiment using Danthonia, Stipa and possibly Themeda spps. |
