Of cannas, dogs, and dryer sheets

A few weeks ago, I blogged about starting cannas from seed. I ended up with four small (2-inch) pots, each containing one seed of banana canna (Canna musifolia). I placed the pots on the sill of our dining room window, which goes almost all the way to the floor. This window gets morning sun and good light most of the day. The pots were in plastic bags to create a warmer and more humid environment. So far so good.

Banana canna (Canna musifolia)
Image source: Wikipedia

A couple of weeks later, we had dinner with friends and when we returned we were greeted by a nasty mess: pots and soil all over the floor, the plastic bags shredded into pieces. Apparently our black lab, forever obsessed with food, thought there might be something tasty inside those plastic bags, which were at a perfect height for her to reach. I’ll spare you my reaction, but in hindsight I do laugh about it—and I have no one to blame but myself. I’ve definitely learned my lesson: Never underestimate a Labrador retriever’s curiosity and always keep things that matter out of her reach!

Only one of the four seeds (just starting to germinate) survived the mauling, and I was extra determined to make it thrive. I’ve had problems in the past with seedlings dying, either from damping off, which is typically caused by a fungus, or from the larvae of fungus gnats which eat the tender roots of seedlings. Fungus gnats are small insects (about ⅛ inch in length) you often see buzzing around plants. They lay their eggs in cracks on the soil surface, and within a week, the larva begin to feast on roots.

There are several remedies to deal with fungus gnats (see here and here, for example). However, I recently read about a solution that promises to be not only quite effective, but also wonderfully fragrant.

Smithsonian.com called it a “modern old-wives tale”: Bounce® dryer sheets keep mosquitoes and gnats away. True or false? Now we know, at least as far as gnats are concerned. Kansas State University Department of Entomology professor Raymond Cloyd and colleagues conducted experiments to test whether Bounce® dryer sheets from Procter and Gamble (specifically Outdoor Fresh Scent™) repel adult fungus gnats. Their finding: Yes, they do, at least under laboratory conditions. To get all the details, read this summary by the American Society for Horticultural Science. The complete study can be found here.

Figuring I have nothing to lose, I decided to place a dryer sheet—fresh out of the box, not previously used—on top of my lone Canna musifolia pot. I cut a hole where the seedling had begun to emerge from the soil and put a small rock on top of the sheet to hold it down. If all goes well, no fungus gnat will go near it to lay their eggs. Of course I have no way of knowing whether there were eggs in the soil already, but I haven’t seen any gnats flying about lately.

Dryer sheet on top of 2-inch pot, held down by a small rock

This certainly isn’t a scientific experiment, just something to give me peace of mind considering this is the only Canna musifolia I have left. But assuming you start with clean (sterile) potting medium, just placing a dryer sheet or two near your seed trays—not even necessarily on them—might be enough to keep gnats away.

One major question is still unsolved though: Is Bounce the only brand that works? Because I must admit that our dryer sheets are Costco’s Kirkland brand.