Integrated Weed Control
Employing a combination of methods to ensure the best outcome from available resources
Seed Banks
Invasive weeds often produce copious amounts of seed which can remain viable for decades. Reducing or eliminating this seed production is a legitimate part of IWC, given the longterm consequences of not doing so. Limiting soil disturbance is an important control measure in areas where heavy seed banks already exist as exposure to light is often all the seeds need to germinate - protect canopy cover too, as newly formed light-wells can trigger weed growth.
Area Mapping
For larger areas, where a full visual overview is impossible, mapping is an essential tool to ensure areas are not neglected - even a simplistic sketch can help. Annual weed inventories remind you of what has already been achieved and also highlight areas that have regressed or need ongoing maintenance. Chunk the area down into psychologically manageable sections using landforms as natural boundaries, giving each a priority rating.
Intensive versus Extensive
Either clearing an area totally of weeds then replanting, or using a more passive approach such as the Bradley Method, or perhaps both. The chosen approach should be considered with regard to weed habitat and revegetation, as unsustainable weed clearance, which then reverts, can create more problems than if the area had been left in abeyance.
Species versus Site
Depending on resources available sometimes it is best to maintain focus on a single weed; for example during a species flowering & fruiting season. In different circumstances better results may be achieved if weed control is site-focused, where a particular area is cleared of all weed species.
Weed Habitat
Minimise areas that could play host to 'weed bombs'. As most weed seeds need light to germinate simple clearance without a follow-up plan can lead to a 'weed explosion', usually worse than the original state if a dormant seed bank is present. Seeds such as gorse are fire-resistant, so a burn-off can often create the perfect seedbed for them simply through lack of competition.
Weed Identification
Observation must come before action. Identify all the invasive weeds to be controlled. Understand their life cycle so the best technique can be matched with their most vulnerable growing period or relevant seed season.
Methods of Control
Some weeds are best tackled using a combination of the following techniques depending on such things as time of year, labour available or even age of the weeds:
1 • Manual - hand weeding is useful on a small scale, especially when removing young seedlings
2 • Mechanical - use mowing and strimming when the aim is to manage rather than eradicate
3 • Cultural - shade, through canopy or mulch, is a natural weed suppressant for many species
4 • Chemical - let empirical evidence guide you in this approach
Disposal
Some weed waste is so persistent that if roots and stems are not disposed of properly they will continue to grow & fruit will still develop seeds. Burning is not successful for some species: burying deeply, solar-cooking or using a transfer station are alternatives. If weeds reinfest because of poor disposal techniques then not only has the clearance effort been a waste of resources it could also have created a problem far worse than if the status quo had been maintained.
