Problem Solver

 * Always follow label directions when applying pesticides. Repeat applications as recommended for best results.

Cosmetic pesticide ban: what does it mean for the gardener?

The City of St. Catharines and the province of Ontario may both pass laws this year restricting the non-essential use of pesticides. Nearly half of Canada’s population is already covered by similar restrictions which aim to reduce the health risks associated with these chemicals. Various studies point at increased cancer rates and other health issues associated with chemical pesticides. Young children are especially susceptible from hand-to-mouth contamination as they explore the world around them. Some very common pesticides that will no longer be permitted for domestic use include the herbicides 2-4-D, mecoprop and dicamba (found in Killex and Weed and Feed) and glyphosphate (Round-Up), as well as the insecticides diazinon and carbaryl (found in many insecticide products). Once the ban goes into effect violators may face fines.

Environmental benefits aside, a pesticide ban limits the methods available for dealing with common garden problems like a bug infestation or a lawn full of dandelions. Environmentally conscious gardeners have been asking for alternative products for years. This increased demand has made many organic pesticides not only available, but economically viable.

So here then is a summary of products that you can use when the restrictions start being enforced.

One word of caution, just as with their chemical counterparts, how you apply organic products can determine the difference between success and failure. Read the label and use these products according to their directions.

Organic Methods For Dealing With Bug Problems
 

Soaps such as Safer’s Insectical Soap are contact sprays that disrupt the insect’s cell membrane leading to death. Soaps are effective against many insects including aphids, spider mites and mealybug. Apply at first sign of problem and repeat weekly for 2 or 3 times and thereafter as required.

Pyrethrins are a natural insecticide derived from the painted daisy. They are found in insecticidal soap products such as Safer’s Trounce and Safer’s End-All or aerosols like Doktor Doom. They control many insect pests including, aphids, mealybug, whitefly, spider mites and scale (applied at the crawler stage). Apply at first sign of disease and again 10-14 days later if required. Pyrethrins are biodegradable but avoid using near ponds and streams as they are toxic to fish.

Ferric Phosphate is effective against slugs and snails. Safer’s Slug and Snail Bait is harmless to pets and any undigested bait breaks down into the soil.

Mineral oil is used to kill over-wintering insects on trees. The oils must be applied in early spring before the leaf buds open and when there is no risk of frost. Mineral oil can be used alone (Green Earth Horticultural Oil) or in combination with lime sulphur (Wilsons Dormant Spray Kit) to control insects and disease. Horticultural oil is also used to control Euonymus Scale in the growing season. Apply to cover all parts of the plant. Another product that works in a similar way is Safer’s End-All. It is made with canola oil and is useful against Euonymus scale.

Nematodes are nature’s most abundant life form and these microscopic worms are found all over the world. The two species of interest to the gardener are Heterorhabditis bacteriophora and Steinernema carpocapsae. These feed on many soil pests like grubs and surface pests like webworms respectively. Nematodes, available under the name Grub Busters or Lawn Guardian, are harmless to people and pets, as well as beneficial creatures like worms. They are easy to apply using a hose-end sprayer. Because nematodes are a living organism be sure to pay attention to the storage and usage directions on the package. While used mainly for pest control in the lawn, Grub Busters or Lawn Guardian are proving effective against many other pests as well including Iris borer, leaf miner and thrip.

Silicon Dioxide or diatomaceous earth, is sold as many different insecticides including Green Earth Insect Dust. It can be used indoor as well as outdoors to control many insects. Can also be applied as a barrier against slugs around susceptible plants like Hostas.

BT Bacillus thuringiensis is packaged in several formulations including Safer’s BTK which is used to control many types of caterpillars on and crops and ornamentals as well as in Aqua-Bac which is used to control mosquitoes by killing their larvae in standing water. It is considered very safe to use since it has little or no non-target effects.

Boric acid or borax is most commonly found in ant bait preparations like Wilson’s Antex.

Neem oil is derived from a tree native to India. Target Neem is available as a spray or concentrate. While is doesn’t kill insects directly it interferes with their life functions like feeding and breeding and so controls pests indirectly. Another benefit is that it affects only insects that ingest plant tissue, sparing nectar eaters like bees and butterflies. Plus it has been shown to have fungicidal properties.

Pheromone traps use a scent based lure to attract and trap beetles and wasps. Safer’s Japanese Beetle Trap should be placed 3 metres away from the plants to be protected. To keep wasps away from outdoor entertainment areas place Scotts EcoSense Yellow Jacket Traps away from these areas. While very effective, these lures may actually attract these pests to your garden so if you don’t have a problem, avoid using them.

Safer’s Sticky Strips are bright yellow plastic cards coated with an adhesive. These attract various flying pests such as fungus gnats, thrip and whitefly. The bugs get trapped in the adhesive.

Organic Methods For Dealing With Fungal Problems
 

Sulphur is available in a powdered form (Safer’s Sulphur Dust), and in a liquid spray (Safer’s Defender). It is used primarily to control mildew, black spot and rust on ornamental plants as well as scab on fruits. Apply at first sign of disease and repeat at 10-14 day intervals as required.

Copper Sulphate which is sold under the name Bordo is used to control disease and fungus organisms on plants. It is effective against blight, leaf spot as well as peach leaf curl, anthracnose and other diseases.

Combination Insecticide / Fungicide Products
 

Roses and some other ornamentals often attract more than one type of problem such as a combination of Aphids and Mildew for example. There are some products that deal with both issues. Safer’s 3in1 spray is both an insecticide and a fungicide.

Organic Methods For Dealing With Weeds
 

Corn gluten meal is a byproduct of corn processing that was discovered to have herbicidal properties in the 1980s. It works by preventing germination of seeds. Environmental Factors Turf Maize is effective on various lawn weeds including crabgrass and dandelions when applied as a pre-emergent control in spring at around the time the Forsythia bloom, and again in fall. Apply at least six weeks before or two weeks after over-seeding. Corn gluten meal breaks down as organic nitrogen (10-0-0) which is an added benefit for the lawn. Environmental Factors Turf Maize contains 98% corn gluten, and is registered as a weed control. Corn gluten meal products with fillers added are beneficial as a fertilizer, but do not have the same weed suppressing properties.

Acetic Acid (Scotts Eco Sense) is a non-selective (kills everything green) contact (must be sprayed on foliage) herbicide for use on driveways, patios and in gardens. It acts quickly and controls many weeds. Avoid using in lawns except as a shielded spot spray to control perennial weeds and avoid spray drift on desirable plants or surrounding turf.

Soap containing fatty acids like Safer’s Topgun is a non-selective herbicide for use on driveways, patios and in gardens. It acts quickly and controls many weeds. Avoid using in lawns except as a shielded spot spray to control perennial weeds and avoid spray drift on desirable plants or surrounding turf.

A final note:
 

Many of the above problems can be dealt with using common sense cultural practices. If you see an infection on a plant cut it out before it spreads and then monitor the plant to see if a pesticide is needed after. Keep the grass thick with regular applications of fertilizer, infrequent but deep watering as needed, aeration and mowing high. This deters weeds. Hand-pull weeds before they become an infestation. Try to determine what the problem is before you spray. If you’re not sure bring a sample in to one of our experts for identification.

As long as you’re going green, consider buying a re-usable sprayer and getting concentrated organic products. Most types mentioned come in a concentrated form. This not only saves you money. It saves on packaging.

The City of Toronto has a great resource page on their web site with many fact sheets outlining cultural practices and organic alternatives to pesticides.

Staff from the Niagara Region will be hosting a Smart Gardening seminar at Rice Road Greenhouses on April 16th, 2009 from 7:00 to 9:00pm