Eco-Friendly Weed Control Myths

eco-friendly weed control myths for dandelions and other plantsWhile the late spring ice and snow wreaked havoc on landscape bedding plants, it does not seem to have affected the weeds all that much. Keeping pesky weeds at bay can be an full-time outdoor occupation, especially along fences, walkways and driveways. Many gardeners would love to find a non-chemical solution to this perennial problem. Most of the solutions that fit this description work, but with some caveats.

The most common non-chemical weed-killing solutions come straight from the kitchen pantry. A mixture of distilled white vinegar (5% acidity) and dishwashing soap is one concoction that can be sprayed to kill weeds.

Another version of this solution adds regular table salt to the mix, for a stronger and more permanent remedy. Both of these work on contact and are often touted as safe and inexpensive. There is some debate about this, however.

Because the vinegar and salt solutions do their damage on contact, they are not selective weed killers. So unlike some systemic chemical herbicides, they kill whatever they touch, but only what they touch. Overspray could do unintended damage to landscape plants other than weeds. And underspraying could result in half-dead weeds.

While supermarket vinegar will easily kill tender annual weeds, it does not usually kill the tougher perennial ones. This requires a stronger vinegar of up to 20% acidity, known as horticultural vinegar, which is an herbicide.

Plant professionals point out that regularly adding acetic acid (vinegar’s active ingredient) to the home landscape is not exactly harmless. Concentrated vinegar is harmful to aquatic life, so runoff and use near bodies of water can be a concern.

The good news about using household vinegar as a weed killer is that it has no long term residual action. But lack of residual action also means repeated applications may be necessary.

A pinch of salt for tougher weeds

Using salt to kill weeds acts by leaching into the soil to dehydrate the plants. This makes the treated area inhospitable to growing any plant for the long term. Increasing soil salinity can also kill beneficial organisms like worms, grubs and helpful bacteria and fungi.

salt for eco-friendly weed control

If you’ve ever gotten carried away with applying salt or ice melt you may have witnessed these effects firsthand with brown grass and foliage. It could take months and a considerable amount of water to return a treated area to a healthy plant habitat. Thus this weed killer is best used in cracks and crevices in driveways, curbs and walkways.

salt for ecofriendly weed control in driveway cracks

There are several convincing arguments that conclude that so-called eco-friendly, homemade weed-killing mixtures are actually more expensive and more toxic to mammals than their synthetic chemical cousins. So look for an upcoming post about other ways of killing weeds without synthetic chemicals.

Eco-friendly weed control recipe

Here is a typical recipe for homemade weed killing spray. Apply on a sunny day with a hand or pump sprayer and douse the weeds thoroughly, but carefully!

  • ½ gallon household vinegar
  • ½ cup salt
  • 2 tablespoons dishwashing liquid
 
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