Spraying Facts for the Garden

An effective spray program can mean the difference between a garden that thrives and one that dies on the vine. Whether you’re a veteran or a novice, organic or generalist, there are some basic spraying facts every gardener should keep in mind.

You should mix spray material as recommended.

Start with the proper spray material. Then follow all directions and precautions on the label of pesticide. A common misconception is that if one tablespoon of pesticide is recommended, two tablespoons will be twice as effective.

Effectiveness will not be increased by doubling the amount of chemical. In fact, higher concentrations of pesticide can harm plants and is against Federal law.

Use proper measuring utensils. Don’t guess at amounts. Measure the pesticides carefully and mix only the amount needed for a job. Keep measuring utensil separate from cooking utensils. Never use pesticide measures for food.

When you spray, remember that "how you spray does make a difference." Spray on target (pest), especially under leaves where insects settle and many plant diseases begin. A haphazard application will not curb an infestation of insects or stop the spread of plant disease.

Spray just to the point of run-off, never drench the plants. You may think more spray is better, but over spraying can injure plants and excess run-off may hit non-target plants.

"On target" spray applications require equipment which give you control over the spray, so use proper equipment.

Use a sprayer with "control" features such as an adjustable nozzle for various spraying jobs, a positive on-off valve for precise application and a long spray extension for easy reach under leaves. This can be a pressure sprayer or a hose sprayer. Dusters can be used for dust applications.

Watch the weather and spray before the heat of the day and always avoid spraying when temperatures are high. High temperatures cause some pesticides to evaporate and decompose quickly. Rain or watering after application will reduce effectiveness by washing the spray material off plant leaves. But most formulations can withstand one-half to one inch of rainfall.

Spray when it’s calm as on a calm day. Pesticide "drift", the movement of spray from the place of release, should be avoided. Drift can also be minimized by spraying at a lower pressure and using the largest practical nozzle opening. Wind speeds should be below 5 miles per hour. Early morning and early evening are relatively calm periods.

Source: David Robson, Horticulture Educator, University of Illinois

Mid-Summer 1998
Five Steps to Healthier Grass in Shady Spots | Tree Tips for Buyers of New Homes | Summer Tree and Shrub Watering Care | Leaf Scorch | Spraying Facts for the Garden | Bug Bites—Grubs | Lawn Care Calendar | Cybergarden Sites | Hort Shorts | Hort Tips | Food Handling: What to Do with Food During a Power Outage | In the Kitchen: Friendship Cake | Food Safety: How to Make A Friendship Cake Starter | Locally Grown: At the Farmers' Market | Health and Household Tips

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