One of my perverse pleasures is perusing Pintrest to find bad garden advice. There’s certainly no lack of misinformation on the web, and Pintrest seems to collect it all. Most advice is simply a waste of time and money—sprinkling Epsom salts on your plants, spraying weeds with vinegar, pouring beer on your lawn. They don’t help, but they won’t kill your plants either. However, yesterday I came across a recommendation that will seriously damage your garden. I was so horrified that I immediately sat down to write this post.
The article that got my blood boiling is “5 Uncommon Ways To Use Common Salt In The Garden,” on the Balcony Garden Web. They like to make lists of ways to use everyday ingredients in the garden. Some of their advice is terrific—cinnamon really is a fungicide, for example, and there are studies to prove it. However, salt is anathema to plants, and the idea of purposely using it in places where you want them to grow is just frightening. So, what do they recommend?
Kill poison ivy. They recommend spraying saltwater (one cup salt to one gallon water) on the leaves of the poison ivy to kill it. While it is true that salt will damage the leaves, spraying it on the leaves won’t kill the root. And if you’ve ever dealt with poison ivy, you know that any piece of living root will happily resprout.
You’d have to saturate the ground to kill the plant. This works—witness the dead trees along highways where salt is used as a deicer. The problem is that this is a permanent cure for a temporary problem. Nothing will ever grow in that spot again. And if the salt leaches “downstream,” nothing will grow there either.
Kill weeds. This idea combines two popular “weed killers”—salt and vinegar. You add five tablespoons of vinegar and two tablespoons of salt to a quart of water and spray it on weeds in sidewalks and driveways.
In this case, the vinegar is pretty much useless. Household vinegar is only slightly acidic, and diluting it this much renders it harmless.
The salt will kill the weeds, although again, the concentration is pretty low. Since they recommend using it on pavement, there’s no concern about killing adjacent plants, unless runoff moves the salt into a landscaped area.
The main problem here is that the accompanying photo shows someone spraying this solution on a dandelion in the middle of a lawn. If it manages to kill the dandelion (unlikely—they’re tenacious!), it will also create a permanent brown spot in your nice, green grass. (My guess is that the grass will die and the weed will thrive—maybe an experiment is in order?)
Deter ants. First of all, I question their claim that “Ants can be destructive in the garden and kill many beneficial insects including earthworms.” (Ahem. Earthworms aren’t insects.) Ants are generally considered beneficial insects! They are extremely effective in controlling the insects and arthropods that munch on our plants. In addition, they do a wonderful job of aerating and tilling the soil—as much as earthworms do.
About the only time they cause problems is when they nurture herds of aphids. In that case, they’re easily controlled.
The article goes on to suggest that you “Just sprinkle common salt in areas near ant trails to help deter them.” Gaah, salt on my soil! No, no, no!
Kill slugs. Thankfully, I don’t have slugs in my garden. If I did, I might use salt (seems kind of mean—I prefer putting them permanently to sleep in a saucer of beer). However, you can be sure I’d move the slug out of the garden before adding salt. To repeat: Gaah, salt on my soil! No, no, no!
Remove rust. Well, all right—salt and lemon juice are abrasive and can remove rust with some scrubbing. But be sure to rinse thoroughly! Both salts and acids are corrosive, and you’ll end up with more rust than you started with.
Salt in soil is a big problem. Few plants grow in salty soil. In some areas with high rainfall, salts are flushed away, or carried below the root zone, but that’s unlikely here in the arid west. The last thing you want to do is add more salt than already occurs naturally.
I should add here that purchased dehydrated steer manure is often extremely high in salt. The cattle are fed a high-salt diet to encourage them to drink more, increasing their market weight. All that extra salt ends up in their droppings. It’s best to avoid using steer manure in the garden—according to a study at Colorado State University, even two applications can increase the soil salt content to toxic levels.
Similarly, if you make compost at home, don’t put salted table scraps into the pile.
So there you have it. Use salt. It’s cheap and can be used in more ways than on your French fries. But please keep it away from your cherished plants. There’s a reason armies used to salt the fields of their enemies!