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Organic Pest & Disease Controls

One of the principles of organic gardening is to avoid using synthetic chemicals to control undesirable pests. Since pests come in all shapes and sizes, here’s a few strategies for you to try. This guide is only a starting point.

Strategies to prevent and control pests and disease

Integrated Pest Management is an overall strategy aimed at reducing or eliminating the amount of pesticides used in horticulture. The three-pronged approach involves: prevention, observation, and intervention.

Prevention starts in the planning phase of your garden. Be sure to check for fire ants and other pests (including small mammals) during the site evaluation and take precautions while you are preparing the garden. Use good quality soil, compost, and mulch. Companion planting (below) to attract birds and “good” bugs is another preventative strategy. You can also release good bugs, such as lady bugs and praying mantis into areas of your garden infested with insect pests. These beneficial insects are available for sale at garden centers and through mail order.

Observation will be an ongoing need in the garden. One of the first steps is knowing the difference between pests and allies (bad bugs and good bugs). Keep an insect guide around the garden to help you identify insects and larvae that you find in the garden. Someone needs to check plants weekly, if not daily. Is the problem concentrated to a particular plant type.

Intervention should always start with the least invasive strategy first. Removing insects by hand and dropping them into a bucket of soapy water is effective, but labor intensive. There are a number of certified organic approved substances that can be used as pesticides in organic gardens (below).

Companion planting is another garden strategy that needs to be implemented in the planting phase. Attract birds with seed and berry-bearing plants: black-eyed susans, coneflowers, cosmos, sunflowers, roses, blueberry, and dogwood, for example. (These will also attract beneficial pollinators!)

Good all-purpose companions: garlic, chives, or marigolds. The smell of these plants deters many would-be pests. Other pairings include:

Home-made organic controls

There are many folk remedies out there. Very few of these home-made remedies have been tested in a controlled setting and we cannot promise you they will work. If you decide to give them a try, monitor their effectiveness during the growing season and keep good records about what works. Here are a couple to try:

Black Spot and Powdery Mildew Spray

3 Tbsp Baking Soda
2½ Tbs horticultural oil
One gallon of water

Spray the mix onto infected plants. Reapply as often as needed. (Try on cucumbers, melons, squash and strawberries.)

Garlic Soup for Fungal/Bacterial Diseases

2 garlic cloves
1 quart water
1/8 tsp liquid soap

Puree garlic in a blender, adding the water slowly & blending 6 min. Strain and add the soap. Use in a spray bottle, 1 part soap to 10 parts water.

Soapy Pepper Spray Recipe

2 Tbsp red pepper
6 drops liquid soap
1 gallon water

Let sit overnight and stir thoroughly. Spray weekly to protect all members of the cabbage family from critters.

Deer deterrent

Mix one egg per gallon of water and spray on plants. Reapply once a week or after rain. Sprinkle human hair around outside of garden. Barber shops will give you bags of it for free but you will get funny looks when you ask.

Human urine is another smell-based deterrent. Just don’t let the neighbors catch you!

If you want to try out more homemade sprays and creative home-made solutions to pests, check out Sharon Lovejoy’s Trowel and Error (Workman Publishing, 2003).

Approved organic controls

Bacillius thuringienses, or BT, is a bacterium that kills leaf-eating caterpillars by invading their digestive system. It is sold under a variety of brand names in the form of a soluble powder that is sprayed on the plant surface and is then ingested by the pest. Be sure to use the right type of BT for the pest you want to control.

Diatomaceous earth is fossilized remains of prehistoric diatoms. The ground-up rock is somewhat abrasive and its content is mostly silica. It creates an abrasive barrier when sprinkled around the base of plants and the moisture absorbency of the substance will desiccate (suck the moisture out of) insects that come into contact with it.

Just for Kids

Make a snake out of worn sections of black or green garden hose. Paint the hose to resemble a snake and hang it over tree branches to keep rodents and birds away from your fruit trees. Build and decorate bird houses to encourage these insect-eating friends to visit the garden.

Sources: http://www.cdcg.org/pests.html; Lovejoy, Trowel and Error

By Henry Owen with assistance from Kathy Metzo and Carol Adams