Compost made from leftover food, straw, grass, leaves and the like can make an equally good soil additive. But compost piles do attract insects that feed off the decaying organic matter. Take care when preparing and using it in your vegetable garden. 

Biological control of insects is another method popular among organic gardeners. It has many advantages. Insect and pest populations can be kept under control by introducing predators that eat the harmful insects but not the vegetables. That reduces the need for artificial chemicals. But selecting which ones are beneficial, and ensuring that they don't then turn on the vegetables, can take a lot of research and continual adjustment.

Planting trap crops that lure insects away from vegetables to 'sacrificial' plants is another form of biological control. It has the same advantage of reducing the need for artificial chemical control, or passively accepting a reduced crop from insect damage. But those crops take up time, space, water, fertilizer and other things that could be used for more vegetables.

It's also true that the chemical compounds used in many insecticides are often derived from natural sources. Strictly speaking, there's no such thing as a non-natural source. All chemicals produced artificially for gardening have their origins in compounds found in the environment.

Pyrethrum, for example, is the base of one of the most popular forms of insecticide. It is used in cans of wasp and other insect sprays and a wide variety of other applications. Yet, it is derived from the blossoms of the pyrethrum flower (Chrysanthemum cinerariaefolium). Most people would think of it as an artificial insecticide, yet it clearly has its origin in a completely natural plant.

Nicotine, by contrast, is a natural organic chemical used as an insecticide. And it is very effective. It is also highly toxic to humans, dogs and wild animals. It should be handled with care. Here again, 'natural' or 'organic' doesn't always mean safe under all circumstances.

Natural, organic mulch is a very helpful soil protector. Leaves, wood chips and other materials from the environment can help retain moisture, or stave off insect and weed invasions. But using black plastic is another very popular (in this case, artificial) mulch. It is great for weed control. It doesn't harm the local environment because it doesn't decay or give off toxic fumes. It can even help with pest control by enhancing solar irradiation.

Which method to use is a matter of individual preference. But modern chemistry has come a long way in the past 50 years. Used properly, contemporary chemicals are safe for the environment and those who consume the vegetables. At the same time, traditional and modern organic methods have a useful role to play in good vegetable gardening practices.