Effective weed control is essential for maintaining productive farms and healthy orchards. Weeds compete with crops and trees for nutrients, water, and sunlight, disrupting the environment and reducing yields.
In the Bay of Plenty region, Table 11 of the Regional Pest Management Plan outlines specific pest plants and recommended control methods, helping growers tailor their approach to local conditions.
The New Zealand Plant Conservation Network highlights methods like shading, hand weeding, and controlled grazing as effective tools for managing invasive species while preserving native biodiversity. For organic farms, options such as manual labour—digging out roots, deadheading flowers, and mulching are options that typically require a lot of people or time. Weed control should be three times a year. Spraying foliage with natural oils like pine or coconut oil can suppress weed growth without harming beneficial organisms.
The Bionet Weed Guide provides a comprehensive list of mechanical, organic and herbicide control techniques, including mulching and root exclusion, which are particularly useful in orchards where chemical use is limited. Herbicide-Based Methods involve cutting and painting stumps with metsulfuron gels (H1–H4), or applying picloram gel to stems (H5). These are typically used where manual methods are impractical or insufficient. By integrating these strategies, farmers and orchardists can create a resilient growing environment that supports both crop health and native ecosystems.
Aimee Snowsill
Environmental Consultant