Battling Garden Pests Without Pesticides

When we use pesticides in our gardens, we expose ourselves and also family members, pets, beneficial insects, and even the plants themselves to harmful chemicals. Such chemicals end up on the food we eat; they can be breathed into our lungs, or leach into the groundwater. Oftentimes they are not even necessary. Hardy plants (the ones we take good care of) can endure a certain amount of insect damage and still bloom beautifully or give us good fruits and vegetables. There are also organic approaches we can take to give them further protection from insect pests.

Planning our gardens properly can reduce the numbers of harmful pests that are drawn to them in the first place. Some like to hide - and even hibernate through the winter - in garden debris. Removing vegetable plants after harvest, and flowers once they're done blooming will deprive our little enemies of convenient homes. Spacing plants to provide for good air circulation, and pulling up weeds as they crop up, prevents gardens from becoming so humid that it promotes plant disease. Also, a good plant guide can provide information about certain perennials (like purple coneflower) that experience little, if any, pest problems.

Healthier plants are less susceptible to attacks. Most of them thrive with abundant sunlight and well-drained soil. Excessive moisture can cause plants to rot and thus invite bugs. Plants can also get stressed if they lack adequate nutrition, or if they're fighting over water with the roots of trees that are growing too close.

Some insects are actually beneficial to our gardens because they're enemies of the undesirable varieties (i.e., they eat them). Beneficials, as they're sometimes called, include ladybugs, lacewings, parasitic miniwasps, and tachinid and syrphid flies. We can attract them into our gardens by growing nectar and pollen-bearing plants like daisies, fennel, mint, dill, and mustard. Certain herbs help to deter pests, also. Anise, coriander, garlic and mint all repel aphids, for example.

Floating row cover is a translucent, fabric-like material that allows water and light to get through while inhibiting insects. It can be draped loosely over seedlings, with its edges buried under the soil. Floating row cover can also cover the sides and top of a wooden frame, which is then pushed firmly into the soil.

A natural pest-killer that can be applied - via sprayer or dust or granules - is BT (bacillus thuringiensis ). Various strains of BT can kill a range of pests that eat leaves treated with it, including cabbageworms, tomato hornworms, black vine weevils, and Colorado potato beetles. BT should be sprayed in the morning or evening, because it quickly breaks down when exposed to sunlight; and most insects don't feed in the middle of the day anyway. It is generally only effective for up to three days, so we should be strategic in our use of it.

Sticky traps can prove effective against insects that are drawn to specific colors. Non-toxic, vegetable based Tanglefoot is a good sticky compound to use: paint it around a colored object made out of cardboard or wood and watch the little pests adhere to it like they would to flypaper. Certain colors will attract different insects: bright blue=thrips, white=tarnished plant bugs, red=female apple maggots, and yellow= a host of critters, including aphids, gnats, whiteflies, and leafminers.