Check the science first: Those viral TikTok gardening hacks could actually kill your plant

DIY gardening concoctions may not always be good for your plants.
DIY gardening concoctions may not always be good for your plants.

This is not a DIY, homemade potions, “this is the way my grannie did it” column.

This is a “just because it was on TikTok doesn’t make it right,” “what was I thinking?” and “check the science first” column about some of the most popular gardening hacks on social media.

Starting with one that’s been around and avidly debated for a long time.

Ever wonder why orchids don’t grow in Antarctica?

Orchids grow naturally nearly everywhere on Earth — from the hot, fetid swamps of Florida (like the extremely rare Florida Ghost Orchid) to the cold windy slopes of the Andes mountains. They constitute around 10 percent of all plant species on the planet. There are over 25,000 species of wild orchids, and nearly a quarter of a million hybrid varieties, with new wild species discovered every year.

Orchids are so adaptable, they thrive on six of the world’s continents, but not on the seventh: Antarctica. It’s not just the extreme cold, but also the environment’s lack of sunlight and moisture, its poor soil and short growing season.

For the casual orchid parent, making sure your plant gets just the right amount of water is a big challenge, and the idea of putting 3 ice cubes on the growing medium once a week is appealing. And, according to the orchid growers at Longwood Gardens in Pennsylvania, overwatering is the number one cause of orchid murder.

Many people have had success with this method. In fact, some universities approve and encourage using it. Others, however, point to evidence that it causes the plant to slowly decline. They suggest instead, running lukewarm water over the roots for a minute or so once a week, letting it drain well, and then returning it to its container that has adequate drainage holes.

There are many varieties of orchids, each with its particular needs, and different tolerances to light and temperatures. To say all orchids like one treatment or another is misleading. For instance, phalaenopsis orchids want a shaded south- or east-facing window and its crown kept dry, while the cymbidium must have a bright sunroom and prefer to be almost completely dry before rewatering.

Check the science first. Look to websites from orchid growers, established gardens and universities. If you’ve become curious about all the native orchids around our state, go to UF’s publication, “Florida's Native Orchids,” at https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/floridas-native-orchids.html for more information.

Can soda pop really save your houseplant?

I recently saw on social media a short video showing a popular carbonated soft drink (name starts with a C) perking up an ailing house plant. Thanks to time-lapse, the conversion took seconds.

What really perked up was my attention. That just didn’t sound right. Finding the science around this one took some time, but this is what I found.

Sugary soda drinks are exactly that — sugary. One favorite soft drink contains a jaw-dropping 3.38 grams of sugar per ounce. That’s almost a teaspoon of sugar.

So, the problem here is that there is no scientific evidence that feeding plants sugar water is going to improve their health. Actually, the converse is true. It can harm and even kill them.

We talk a lot about plant sugars, so maybe that’s where the confusion begins. But plants make their own sugars in the form of glucose through photosynthesis. They have no tiny little green digestive systems to break down the sugar from soda pop. The sugars we consume are more complex than glucose and are not easily broken down in any circumstance.

Additionally, sugar water, like salt water, can keep your plant from absorbing moisture. Sugar can cause reverse osmosis, making a plant lose water.

If that’s not enough, soil that is saturated with sugar/water/soda pop can attract harmful micro-organisms that can threaten the plant’s health.

However, using sugar-in-water with cut flowers that are already dead is helpful in preventing them from wilting. You may have read recently that the small packets of crystals that come with cut flowers contain preservatives, typically sugar and bactericide. Since plant stems can absorb the sugar, which revives their carbohydrates, (and if you follow label instructions) this small amount of sugar can keep cut flowers looking fresher longer.

Are you making a salad or wiping out weeds?

Recipes for homemade weed killers are, and have been, a social media mainstay from the beginning. It seems everyone has a foolproof concoction to kill something.

A lot of those concoctions include vinegar, and some contain oil, to boot.

As much as we all are trying to find more gentle solutions to our gardening woes, this isn’t the way to go.

Start with the fact that our kitchen variety vinegar contains only 5% acetic acid. The USDA reports that to be an effective herbicide, vinegar needs to contain at least 20% acetic acid.

This large concentration can be deadly to beneficial insects like bees and butterflies, and it can be lethal to smaller creatures like worms and frogs.

When we use homemade recipes, we may have control of the ingredients, but not necessarily the proportions. Our product won’t be identical from one batch to the next unless our kitchens double as a lab.

We don’t have any real information about the amount of our home-made product to use. It’s easy, then, to over or underestimate the effective amount.

The homemade vinegar mix will certainly kill the top of a plant by burning it, but it won’t necessarily kill the entire plant. The weed comes straight back from the roots. Of course, very young tender plants will be completely killed, but the young ones aren’t our problem. They’re easy enough to pluck out. It’s the expanse of lawn we’re after.

Checking the science is easier with this one. Start with UF’s publication, “Homemade Weed and Bug Killer” at https://blogs.ifas.ufl.edu/pesticideinformation/2021/05/13/homemade-weed-and-bug-killer/.

So, the next time you’re in the mood to chill with your orchids, pop with your house plants, or treat your lawn to a tasty dressing … just don’t. Instead, check the science first.

Paula Weatherby is a Master Gardener Volunteer with the Duval County Extension Service and the University of Florida/IFAS. For gardening questions, call the Duval County Extension Office at (904) 255-7450 from 9 a.m. to noon and 12:30 to 3:30 p.m. Monday-Friday and ask for a Master Gardener Volunteer.

This article originally appeared on Florida Times-Union: TikTok gardening hacks: Are they too good to be true?