The positives & negatives of invasive weeds
The potency of words lies in their ability to evoke strong, powerful emotions. Discussions held within an open, online forum by the PCA or Amenity Forum, prompt fierce and diverse reaction if you mention “Japanese Knotweed” or potentially even worse “Glyphosate”. Take the term 'weedy,' for example, which typically carries a negative connotation, implying something flawed or feeble. However, this perception doesn't align with the reality of actual weeds. In truth, most weeds (using a working definition as 'plants growing in the wrong place at the wrong time') are integral components of our natural flora. They demonstrate remarkable adaptability by competing vigorously for light and water, and they prolifically produce flowers, nectar, and seeds to ensure their survival.
Embracing nature's diversity
Gardeners, councils and scheme operators are increasingly encouraged to embrace these unassuming wanderers and cultivate wild areas or even participate in “No Mow May” thanks to the Plantlife campaign, with the idea to “liberate lawns and provide a space for nature”. This approach maximizes opportunities for invertebrates and all the birds and animals that rely on them for their well-being, although chopping it all back down again in June seems slightly counterintuitive. The concept of the "ideal garden" is continually evolving, and now it encompasses the inclusion of wildflower bays which may of previously been identified as weeds. Beyond the confines of the garden, these so-called weeds are, in fact, valuable "service providers" offering an astounding amount of balance to our eco-equilibrium.
Unravelling the challenge
Is it time to reconsider our attitudes and reactions to the existence of these foreign colonizers? With a slow erosion of UK native flora, this is undoubtedly a topic worthy of discussion. Should every non-native plant be labelled as a problem, or should a meticulous evaluation of site-specific conditions be considered? Japanese Knotweed, Giant Hogweed, Buddleia, Horsetail are all considered invasive plants, each bringing their own issues and requiring specific competence of expertise. At the very simplest level, surely we should accept that non-native and 'invasive' plants should never be intentionally planted, and if they are already present, measures must be taken to control them and prevent further spread to natural habitats as outlined within the Wildlife & Countryside Act 1981.
Evaluating invasive weeds
What considerations should be part of our thought process when we come across Cotoneaster (C. horizontalis) thriving in an urban planting scheme? It could be the sole plant in the vicinity, serving as a nesting site for sparrows during summer or a feeding ground for blackbirds in winter. On the other hand, Himalayan Balsam is often regarded as a beneficial source of nectar for insects and pollinators, given its late flowering season when other native species have already waned. However, should we simply leave it untouched and allow it to overtake riparian habitats, becoming potential pathways for vermin, and harming native species in the process? These are crucial questions to ponder. The answers to these questions are never simply ‘yes’ or ‘no’…
Assessing Threat Levels of Invasive Species
The assessment of each invasive species must be conducted individually, taking into account its potential threat to the local ecosystem or its likelihood to cause disturbances in neighbouring gardens. Invasive weed experts, well-versed in the features and traits of each plant, thanks to an ongoing library of guidance notes and training, will rely on their expertise, providing a flexible, analytical approach, adapting risk assessments, and offering outcomes that are compliant with the law but also best for the client and the wider environment. The aim is to enhance objectivity and promote a consistent approach across the sector, with organisations like the PCA and Amenity Forum, acting on behalf of its members as Captains along this voyage.
The trials & tribulations of integrated weed management
How does this influence our approach to Japanese knotweed, Giant hogweed, or any specific INNS? In essence, the approach must be targeted to minimize adverse effects on other flora, ensuring sustainability by using the least possible amount of herbicide. Moreover, it needs to be adaptable, considering the merging seasons and unpredictable weather, as rigid strategies may prove insufficient.
Realising that a multi-factorial approach may not fundamentally alter the typical response scenarios for these specific species, we gain the opportunity to expand our perspective and address all invasive weeds covered by the Wildlife & Countryside Act, as well as new emerging threats that are yet to be listed. This way, we can develop more comprehensive and effective strategies for invasive species management.