Pest management, in an organic garden, relies on a combination of common-sense practices. It involves a range of complementary techniques aimed at controlling the numbers of harmful insects in the garden. These involve: These complementary techniques are key components of an Integrated Pest Management approach.Healthy soil and healthy plants
Healthy soil is the essential foundation of any organic garden. Healthy soils have a high level of organic content and minerals, suitable ph for growing vegetables (6.5 - 7) and plenty of worms and beneficial bacteria.
Companion plantingSome plants assist in the growth of others, by attracting beneficial insects, regulating pests, repelling harmful insects, providing nutrients, or simply providing a shaded microclimate or climbing support.
Jackie French in her book, Guide to Companion Planting in Australia and New Zealand, warns that "many companion planting hints have been passed on from book to book, all based on European observations - whereas Australia has quite different pests and predators, and garden relationships - and the 'companion planting' that works overseas may not work here at all."
Beneficial insectsAphids, cutworms, mealybugs and other pests can multiply and destroy your vegetables. Organic gardeners enlist the aid of beneficial insects to battle and help control pest outbreaks. To nurture these beneficial insects in your garden, - do not use pesticides which kill beneficial insects as well as pests,
- use organic sprays, if you must, but remember that they are not harmless, e.g. sulphur fungicide harms parasitic wasps and predatory mites, insecticide soap harms hover fly larvae,
- grow flowers to feed beneficial insects. Among the favourites are flowers such as daisies, marigolds, sunflowers, thistle, yarrow, parsnip, parsley, dandelions and fennel (a study has shown that the fennel flowers attract almost 500 different insects).
- provide 'nursery' plants for pests in your garden to feed beneficial insects; a “nursery” plant is one which supports pests with no ill effect, e.g. the common nettle supports the nettle aphid which does not attack other garden plants. Nettles therefore attract many beneficial insects, particularly ladybirds, to your garden.
- provide safe cover; ground dwelling insects do not like bare soil, therefore don't be too tidy !
Preventing pests and diseases through good garden hygiene is the best strategy. Remove weeds, use mulch to suppress weed growth, inspect plants regularly for any leaf chewing insects or disease symptoms and dispose of any spent crops that may be diseased. Disinfest equipment if you have been working on diseased plants. Pick up fallen fruit to avoid the spread of disease. Crop rotation is "the successive planting of different crops on the same land to maximise soil fertility and help control pests and diseases". Some plants are referred to as “heavy” feeders, while others are “light” feeders. For example, the Brassiaceae family are mainly heavy feeders and will take a lot of nutrients from your soil, the Alliaceae family are light feeders and will not do well in a rich soil. Therefore it makes sense to plants onions after cabbages! | Heavy Feeders include potatoes, tomatoes, cauliflower, broccoli, cabbage, sweet corn, lettuce, cucumbers, zucchini, spinach, lettuce and Asian greens. Light Feeders include onions, leeks, garlic, beetroot, carrots, parsnips and silverbeet Legumes include peas, snow peas, broad beans, runner beans, snake beans and okra. Green Manure Crops are crops grown, not to be harvested, but to be worked back into the soil. These are generally comprised of thickly sown annual grasses and/or legumes, | Sustainable Gardening Australia's four-bed crop rotation:
|
| Season One | Season Two | Season Three | Season Four | | Bed One | Legume | Heavy Feeder | Light Feeder | Green Manure | | Bed Two | Heavy Feeder | Light Feeder | Green Manure | Legume | | Bed Three | Light Feeder | Green Manure | Legume | Heavy Feeder | | Bed Four | Green Manure | Legume | Heavy Feeder | Light Feeder |
|
that are tilled back into the soil before they flower or form seed heads. They add nutrients during their growing period and organic matter to soil in vegie patchesOrganic gardeners use natural, biological ways of protecting and growing their crops. Sprays used by organic gardeners are natural sprays, without harsh chemicals.
IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment. The main part of IPM is observation. It involves the techniques described above, e.g. - Manual removal of insects like snails, slugs and scale.
- Setting traps like beer, pheromone, hessian and soap.
- Watering and feeding your plants correctly so that they are healthy and vigorous.
- Developing a healthy friable soil with good drainage.
- Employing good garden hygiene, which means cleaning up around your garden pulling badly infested plants, old fruit and leaves.
- Encouraging predatory insects like lady bugs, lacewings, lizards and frogs.
|
|
