What's Bugging You
Pest Control Strategies
An insect or
disease only becomes a pest when its numbers increase to the point where serious
damage is inflicted on plants. Next time a plant in your garden is affected by a
pest or disease problem ask yourself why it was so susceptible to attack in the
Strategies to Avoid Pest and Disease Problems
Grow pest and disease resistant varieties.
different vegetables and herbs together rather than growing a
monoculture of one crop.
use of all pesticides. They kill indiscriminately both beneficial and
Practice crop rotation.
habitat and refuges for beneficial species.
Accept minor imperfections. Which is more harmful, the spot on a leaf of
silver beet or the chemical sprayed to control it?
identify good insects from bad.
of when pest and disease problems occur. You may be able to avoid
growing that crop at that time next year, select a different variety or
grow it in a different way to avoid problems in the future.
- Less Strife -
The easiest way to have a pest
free garden is to have a healthy soil and strong growing plants. Trying to grow
plants outside their climatic range, drought, lack of nutrients, compacted
soil and other factors that stress your plants also make them more
susceptible to attack by pests and diseases.
Healthy Soil -
Healthy Plants -
Incorporating organic matter into the soil not only improves the soil structure
and texture, it helps you and your plants beat pest problems.
Organic matter can
improve the water-holding capacity of sandy soils and improve drainage in clay.
Nutrient rich organic matter such as composted plant or animal manure will also
provide nutrients for plants and soil organisms like worms. Organic matter also
contains many beneficial fungi and parasitic nematodes.
that commercially produced compost materials have all the life pulverized,
deodorised and processed out of them. Use them as a last resort. The most
biologically active compost is the one you make yourself, regardless of your
skill in compost making. See 'Organic Guide to Composting' by Jack
Crop Rotation -
Related plants often suffer from
the same pest and disease problems. When growing vegetables, try to plant at
least four different family groups in a row before returning to the original
crop. For example beans (Fabaceae) may be followed by cabbages (Brassicaceae),
carrots (Apiaceae) and tomatoes (Solanaceae) before replanting peas or any other
member of the Fabaceae group.
Diversity of planting including
growing plants from the daisy (Asteraceae) and carrot (Apiaceae) family attracts
beneficial predators and parasitoids to your garden that will help to control
damaging pests. Companion planting works on this principle.
- Encourage insect eating
birds into your garden by protecting them from cats and providing safe nesting
sites and water. Cool moist refuges, rocks, logs and leaf litter will provide
habitat for lizards, frogs, centipedes and spiders who will all aid in
controlling pests, creating a balance within the garden. Beneficial species
include lacewings, hover, robber and tachinid flies, ichneumon wasps, ground
beetles, predatory mites, ladybeetles and dragonflies.
- Gardeners wishing to
avoid using highly toxic chemical sprays must be prepared to tolerate a certain
degree of damage until predators increase sufficiently in numbers and the
influence of other strategies begin to return things to their natural order. In
the mean time there are a number of low toxic options available at your local
is an edited extract from my book, 'Organic Vegetable Gardening',
published by ABC Books). See