I get a lot of (mostly) good lawn questions. No big surprise there. More surprising (OK, annoying!) is how many gardening myth questions my Extension colleagues and I get – to include the use of magical, restorative tonics and elixirs for every part of your landscape.
Is this yet another example of if “you can find it on the internet”….watch Jerry Baker promote it during PBS fundraising week….or see it on the local news, that it must work? While the list of lawn care myths and remedies is long, let me comment on a particularly annoying one that surfaces whenever watering restrictions are imposed here in Colorado – that of the lawn drought tonic.
Tonic promoters claim their cocktail will fertilize the lawn and help eliminate “bugs”, disease and thatch – all while keeping the lawn green with minimal watering. Many websites attribute its origin to a golf course superintendent. Self-proclaimed gardening “expert” Jerry Baker, creator of a myriad of just plain weird landscape tonics, claims the recipes as his. Whatever the source, I assure you that no self-respecting golf super would ever attach his/her name and reputation to such a concoction. If you do an internet search, you can find dozens of sites promoting variations of the lawn tonic. A frequently cloned reference on many sites is a Denver television station story about the tonic that ran years ago during one of our droughts – and which was resurrected when Front Range watering restrictions became a reality on April 1st. You can read about it on the internet, however, to save you the time and spare you the aggravation of watching it, here is the lawn tonic recipe. NOTE: Including it here DOES NOT imply any endorsement. To the contrary, I recommend that you don’t use it.
The “Lawn Tonic”
-One full can of regular pop (any brand, but no diet soda)
-One full can of beer (no light beer)
-1/2 cup of liquid dishwashing soap (do NOT use anti-bacterial dishwashing liquid)
-1/2 cup of household ammonia
-1/2 cup of mouthwash (any brand)
-Pour into 10-gallon hose-end sprayer (other sizes will work too)
-In high heat, apply every three weeks
So…does anything here have any merit when it comes to caring for a lawn? Maybe. But even if there are potentially beneficial ingredients here, one thing I’ve noticed after reviewing many lawn tonic recipes is that the general recommendation is to “apply it to the lawn”. Rarely is there any suggestion as to how large of an area that a single recipe should cover. More importantly, none of the recipes I read gave directions for what setting to use on the hose-end sprayer when applying the tonic.
Another problem with these recipes is that they recommend the use of household ammonia. First, the concentration of household ammonia varies with brand. Second, using household ammonia as a nitrogen source isn’t the best of ideas. The ammonia…the nitrogen…is in a form that is good for cleaning floors, not for fertilizing plants. I will spare you the chemistry, but take my word: it’s not a safe (for plants anyway) fertilizer source. And consider this: the amount of nitrogen (from the ammonia, since nothing else in the recipe contains nitrogen) provided by a single batch applied to ONLY 250 square feet of lawn is equivalent to around 0.1 pound of N per 1000 square feet. Clearly this is not a safe, efficient, or cost-effective way to apply nitrogen to a lawn.
What about the beer? The claim is that the yeast and other beneficial microbes in it will help thatch decompose and the carbohydrates and microbes in ONE CAN OF BEER will somehow rejuvenate the soil flora of your entire lawn! In reality, the beer provides little more than some extra water and a small amount of sugar, as the yeast and any other microbes in the beer are dead…so there are no yeast or “good” microbes being addedto the lawn. It’s equally ridiculous to believe that the infinitesimally small amount of sugar applied with the soda could provide anything more than an infinitesimally small benefit to the lawn. The dishwashing soap may act as a wetting agent, perhaps relieving some water repellency in a thatchy lawn that has become too dry.
Curiously, most lawn tonic recipes warn against using anti- bacterial dish soap – ignoring the fact that the next ingredient in the recipe, mouthwash, is itself anti-bacterial in nature? If the amounts of nitrogen and other potentially beneficial ingredients are present in quantities too small to have a real effect on lawn quality, why do people believe this stuff works? Perhaps it is that anyone who will go through the hassle of mixing up and applying these tonics many times throughout the growing season is someone who is likely to pay closer attention to mowing, watering, and aerating their lawn? And perhaps they are also fertilizing their lawn with other sources (many sites promoting the lawn tonic also encourage the use of natural organic fertilizers!)? Remember that devoted tonic users are also hand-watering their lawn as often as once every 2-3 weeks. This could provideenough water to mask dry spots from poor irrigation system coverage, spots that would be otherwise more apparent during times of watering restrictions. Of course, there is always the “placebo effect” – if you believe that it works…then it works! Clearly no one wants to admit that they are wasting their time (and beer!) spraying a totally ineffective mix of household cleaners, oral care product and party beverages on their lawn. Can using it hurt anything (besides your pride, perhaps, after reading this)? Yes, if basic lawn care practices are ignored under the mistaken belief that using the tonic will provide adequate fertilization and can fix any and all lawn problems. If legitimate, common sense lawn care is practiced by tonic devotees? Then applying the tonic is harmless and little more than recreational lawn care that provides the home gardener with some exercise and the lawn with insignificant amounts of nitrogen and wetting agent. One thing you can bet – anyone who applied lawn tonic before this week’s snowstorm will confidently say over the next few weeks “See…it works!”. The inch or so of slow-release water, return of spring (warmer temperatures and more hours of sun), and release of soil organic N had nothing to do with their lawn greening up…but don’t confuse me with the facts!
Interested in the science behind, and potential benefits of, common home-grown garden remedies and tonics? In his book “The Truth About Garden Remedies – What Works, What Doesn’t & Why”, Dr. Jeff Gilman, a professor and Extension horticulturist at the University of Minnesota, writes about the history and potential benefits of age-old garden remedies. In it he logically debunks any potential value of spraying your yard (or other plants) with beer and soda, and explains why using household ammonia as a fertilizer source is just damn dumb. Jeff is also a frequent contributor to another excellent hort blog that he and 3 university colleagues started a few years ago, The Garden Professors.