More and more often, I get calls from gardeners wanting to solve some emergency garden pest crisis as soon as possible and "chemical free."
First, technically speaking, there is no such thing as "chemical-free." Everything is made of chemicals. Plants are made of chemicals, we are made of chemicals, even water is a chemical. The goal should be to find "the safest way possible."
Secondly, the safest, most "chemical-free" way to deal with garden problems is by avoiding them altogether through Integrated Pest Management. IPM is a method in which you make it more difficult for pests to infect the plants through a variety of different means - and resort to using some sort of chemical pest control as a last resort.
One thing people have to remember is that the term "organic," even "certified organic," doesn't mean pesticides aren't used. There are a number of organic pesticides available that are derived from a natural source - usually a plant or bacterial extract or a naturally occurring mineral. These can be used to safely control many garden problems.
This is much better than what I call "organic by neglect," where a gardener allows diseases and insects to thrive and proliferate just for the sake of being "chemical-free." While these products are generally safer than their non-organic counterparts, it is still necessary to read the label, use the proper personal protective equipment and apply it correctly.
You can find a full list of organic control options on the OMRI (Organic Materials Review Institute) list, available at omri.org. This is the group that certifies all products for organic certification.
One of the unfortunate consequences of this "chemical-free" mentality is people turning to wacky home remedies they find on the Internet. Many of those remedies are (gasp) made with chemicals. Common ingredients in these concoctions are vinegar, Epson salt and dish soap (all chemicals). These mixes are usually pretty ineffective at best, and more dangerous than a commercially available treatment at worst.
Things like Epson salt, dish soap and vinegar can be more damaging to non-target organisms such as earthworms and other soil-dwellers. What's scarier is that people think because they aren't using "chemicals," they don't have to use protective gear. Wrong. I wouldn't want a lung or eye full of vinegar, salt and soap.
Many people tout the weed-killing properties of vinegar. A spray of vinegar can damage or burn plants, which may kill annual weeds. However, it does not kill perennial weeds.
Some people even go in search of super-concentrated, horticultural grade vinegar to get the job done faster. The acid in this vinegar is so strong it can burn the skin right off of your hands. Even the common commercial glyphosate weed killer isn't that dangerous. It turns out glyphosate, the generic chemical in weed killers such as Roundup, is relatively safe when applied properly and with the proper equipment.
I've seen people buying flame throwers to torch weeds or propane-powered weed burners. It has the same effect - kills annual weeds but not perennials. I've also seen more than one account of someone burning his or her house down by trying to burn weeds.
The best "chemical-free" way to kill weeds is through mulching. A thick layer of wood chip mulch (we're talking 8 or more inches), can suppress weeds pretty well.
Most folks will turn to landscape fabric to suppress weeds, which most experts agree isn't very effective and is a pain to remove. In the vegetable garden, try a mulch of straw or shredded newspaper.
There are a few things you can do to help reduce the number of insect pests in the garden.
First, encouraging beneficial predators for these insects by planting a variety of flowers can be a good way to reduce pest numbers. In the vegetable garden, crops that don't require insect pollination (such as leafy greens, broccoli, etc.) can be covered with row cover material to exclude insects. If you don't have a huge number of insects, you can also remove them by hand from the crop.
There are several organic control options for insects if needed. Pyrethrum, an extract from a chrysanthemum flower, is a good broad-spectrum insecticide. Rotenone, another plant extract, is another common insecticide. Horticultural oils and soaps are good, typically safe, ways to control many small, soft-bodied insects like aphids, spider-mites and scale.
Some folks may try to use a product made with diatomaceous earth, but that isn't really effective on plants (it falls off) and can cause lung issues if inhaled by humans or pets. If the pest is a caterpillar-type pest, like a cabbage worm or hornworm, a product containing Bacillus thuringiensis (Bt), a common, naturally occurring bacteria, can provide an effective means of control.
There are several "home remedies" for plant diseases that also don't work, from spraying baking soda and milk to treating with bleach (which, by the way, is a registered pesticide). There are better ways to control diseases.
First and foremost, mulching can help reduce the spread of diseases from splashing spores from the ground.
Secondly, choosing plants that are resistant to diseases is key to reducing disease. Diseases are easier to prevent than to treat, especially when the disease moves through the plant. The key to control is to scout the garden for signs of disease.
Once you see disease, it should be removed immediately - either by pruning out affected parts or removing whole plants. Using a protective treatment on the rest of the plants will help limit spread.
One common organic product used for disease control is copper, usually in the form of copper sulfate. This has both anti-fungal and anti-bacterial properties. However, I caution against overuse. The copper never breaks down, and overuse can result in a build-up in the soil that limits the growth of good soil microbes.
Sulfur can also limit diseases and the same build-up. Conventional fungicide sprays don't have the same residual effect as these minerals.
Another new organic product on the market is a biological control - a spray that uses bacteria to control other bacteria. The product I have used is called Serenade, from Bayer. It is a spray-on bacteria that reduces other fungi and bacteria. It is used more as a preventative, applying it through the season to avoid infection rather than after the plant is infected. It worked pretty well for me.
Just remember that there are effective, safe ways to control garden problems without falling for those online "recipes" that usually do little and may even be more harmful. By preventing pests and eliminating them safely, you can have a happier, healthier garden without all the online quackery.
n Begin spraying trees after petal fall.
n Seed parsley outdoors.
n Celebrate National Arbor Day.
John Porter is the WVU Extension Service agent for agriculture and natural resources in Kanawha County. Follow him on Facebook,
Twitter at @WVgardenguru and online at
wvgardenguru.com. Contact him
or 304-720-9573.