The removal of numerous introduced weeds in the park has been a priority for the Friends over the years. Here are some relevant sections regarding weed control techniques and resources:
Weed Identification:
To aid in identifying plants, the following books have proven useful:
“It’s Blue with Five Petals” (available in our library): This fantastic resource provides information based on a plant’s flower color and number of petals, with scale bars for reference. Note that it does not include grasses.
“Plants of the Mount Lofty Ranges and Adelaide Region” (available in our library): An excellent resource, but it requires knowing the plant’s family to find the corresponding page or browsing through the color plates. This book does not include scale bars.
“Grass Identification Manual for Everyone”: As the title suggests, this manual is specifically focused on identifying grasses and is highly useful.
“Stop Bushland Weeds” (available in our library): This book features common weeds and provides notes on native plants they might be confused with.
The Bushland Weeding Code:
The following information is sourced from “Stop Bushland Weeds: A Guide to Successful Weeding in South Australia’s Bushland” by Meg Robertson, published by The Nature Conservation Society of South Australia in 1994.
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Look before you weed: It is crucial to identify the locations of native plants before initiating weed removal.
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Choose effective and selective weeding techniques: Select the most appropriate method for each plant and its specific location.
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Adapt to the season and weather conditions: Avoid pulling or grubbing weeds when the soil is dry and the roots may break off. Similarly, avoid trampling plants when the soil is too soft. Wear appropriate footwear and gloves.
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Minimize trampling and trail formation: Scatter the team of workers to prevent the creation of new trails. Wear soft-soled shoes and clothing that does not carry weed seeds or drag on foliage.
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Prioritize small weed removal before dealing with larger weeds: Remove small weeds growing beneath larger ones before tackling the larger plants.
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Avoid damaging native plants: Take care not to drop or fell large weeds onto native plants or drag boughs through the bush.
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Disturb soil as little as possible: If soil is disturbed during the weeding process, replace and press it down, and restore leaf litter.
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Thoroughly remove weed parts: Ensure that any parts of the weeds that can regrow, such as ripe seeds, seed heads, bulbs, rhizomes, and runners, are removed. Break up the remaining parts into small pieces and scatter them as mulch, especially in the areas where weeds have been removed.
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Perform follow-up work: Before moving on to weed a new area, make sure to conduct necessary follow-up activities.
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Prevent scattering of weed seeds or bulbils: Remove any weed seeds or bulbils that could disperse into the weeded zone.
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Avoid creating large openings when clearing dense weed growth: Provide growing space for native plant regeneration but be cautious not to create significant openings.
Weed Removal Techniques:
The following techniques are sourced from the Watiparinga Management Plan:
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Hand-pulling: Suitable for seedlings and young plants of woody weeds like olives, African daisies, and boneseed, provided the soil is moist. Shallow-rooted species can also be hand-pulled when they have grown relatively large. Some plants that reproduce through means other than seeds require careful handling and should be removed from the reserve in bags for proper disposal.
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Grubbing: Larger plants can be removed using grub-axes, mattocks, or pelican hoes. Minimize disturbance, especially when sensitive plants are
nearby. In such cases, cutting and swabbing may be preferable to avoid physical or sudden changes to the microclimate.
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Treading down: After removing a weed, firmly tread down the disturbed soil to minimize the chances of creating open seedbeds susceptible to re-infestation.
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Cut-and-swab: This method involves using a chemical herbicide for weed control. It is less likely to affect neighboring vegetation compared to spraying and is effective on many woody species such as ash and olive. The weed is cut, and the herbicide is applied to the freshly cut surface. Take care to perform this treatment during the plants’ active growth phase, preferably in late spring or summer, and avoid rain within the next four hours.
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Frilling: Frilling is employed for large multi-stemmed trees like olives. The stems are deeply slashed at an oblique angle near the root stem junction, and the cut surfaces are immediately swabbed with an herbicide mixture using a flat paintbrush. Remove twigs and sprouts from the base and ensure no green leaves remain. It is advisable to remove soil from the base of the trunk and deeply slash the stem below ground level. Prevent cut surfaces from drying before applying the poison.
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Recycling and mulching: It is important to recycle nutrients from cut-off stems and boughs. Small woody stems can be left to decompose and form mulch, while larger boughs should be cut into smaller portions and spread over a wider area. Strategically place the mulch material to avoid covering regenerating indigenous species. Mulching can also be used to deprive unwanted herbaceous weeds of light.
Follow-up and Monitoring:
Regular monitoring of weeded sites is crucial. It is essential to follow up by hand-pulling emerging seedlings after removing adult weeds to prevent re-infestation.
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Weeds and Fire:
The following information is taken from “Stop Bushland Weeds: A Guide to Successful Weeding in South Australia’s Bushland” by Meg Robertson, published by The Nature Conservation Society of South Australia in 1994.
Native plant communities have evolved with fires. Native plants regenerate through various means, such as seeds released from fire-resistant woody capsules, seeds in the soil, or resilient stems, roots, lignotubers, or bulbs.
Weeds in bushland also possess adaptations that enable their persistence. After a fire, areas where a few weeds were present may experience an abundance of weed seedlings. For instance, boneseed, broom, or African daisy seedlings can form dense carpets, smothering emerging native plants.
To prevent weed seed maturation and further contribution to the weed seedbank, it is important to remove weed seedlings by hand after a fire. Extra efforts at this stage can prevent degradation and reduce long-term work.
Strategies for Specific Weeds Found in the Park:
For detailed strategies concerning specific weeds found in the park, such as blackberry, Bridal Creeper, and Boneseed, please refer to the Weeds Australia website and the National Weeds Strategy.
Note: The information provided above is sourced from various references and does not constitute personal advice. Please refer to the mentioned resources for further details and consult local experts or authorities for specific guidance on weed control in your area.