The Botanic Gardens has not applied pesticides to our plants since 2001. The results have been very successful: our plants remained healthy and performed well despite the absence of insecticides and fungicides.
This is part of our sustainable approach to gardening which involves the use of methods that are productive today without diminishing future soil health, plant performance or yields. This can be achieved by proactively implementing beneficial practices, such as careful plant selection.
A key to successful sustainable gardening is growing high performing plants that remain healthy without pesticide intervention. None of our trials are sprayed so the plants we recommend should also succeed in your garden without pesticides. Our recommendations are available on our website or as leaflets from our Huakaiwaka Visitor Centre.
It is particularly important to avoid anything that impacts soil health and the vast communities of beneficial organisms present in a healthy garden ecosystem. A good place to start is minimizing pesticide use, as the chemicals that are used to control pests and diseases invariably also cause great damage to beneficial organisms. This is important, as the greater the quantity of beneficial organisms in an ecosystem, the healthier it is.
Other practices to avoid include working very wet soils (e.g. rotary hoeing) as this can damage soil structure.
Practices that optimize garden health include regular applications of organic mulch and/or compost to help to sustain soil life and benefit plant health. Organic matter and lime are particularly beneficial to earthworms that help build soil structure, aerate the soil and allow oxygen to get to the roots.
Using a variety of different plants in a garden increases biodiversity and will reduce the incidence and spread of pests and diseases. Soon insects and bird life will be your pest control.
Allow sufficient space between plants so air can freely circulate. This will reduce the build-up of diseases, most noticeably in disease-prone crops such as roses and hebes.
It is important to locate plants in suitable situations (i.e. shade plants in shade, sun-loving plants in sun, moisture-loving plants in wet soil, etc).
In vegetable gardens and annual beds it is advisable to rotate your crops so pests and diseases do not build up in the soil. This can simply be achieved by planting crops in a different part of the garden they occupied last year.