Mothballs, pot recycling and biodegradable pots

You know me: I often write about the prevalence of bad gardening advice so, hey, here I go again. This time, let’s talk about how often we gardeners hear stuff that’s either dangerous, or stupid or both. Got a tree stump you need to remove? “Pour gasoline on it,” I’ve heard more than one gardener advise. PLEASE don’t do that. Need to get rid of moles? “Stuff Juicy Fruit chewing gum in their holes,” advise ill-informed people who believe the story that the gum, lord knows how many sticks, will cause intestinal blockage. It won’t, but even if it did, don’t do this either.

And here’s another thing you ought not do — use mothballs outdoors. (Honestly, though, who wants to wear sweaters and use blankets that smell like mothballs either?) Anyway, I have no idea who first started running about telling gardeners that mothballs are great for curtailing outdoor pest problems, but the strategy has been around a long time and is still going strong, according to my latest Google search. The trouble is, it’s a federal offense to use mothballs for an off-label reason such as animal control. And there are a lot of good reasons for that.   

Regulated by the U.S. Environmental Protection Agency, mothballs are pesticides capable of harming all living things, especially children and pets who may mistakenly eat them thinking they’re some kind of treat. Mothballs are also harmful to the environment because, as they deteriorate, they contaminate groundwater, soil and plants (the pesticides in mothballs bind to soil and are taken up by plants.) Labeled for use to kill moths and other pests that destroy fabric, mothballs are supposed to be used only in airtight containers. That’s because the vapor from their active ingredient, usually naphthalene or paradichlorobenzene, is toxic. As the fumes build up inside a closed container, the pesticide reaches a level that kills the moths.

When we smell the terrible stink of mothballs, however, we are the ones breathing in the pesticide fumes. And those fumes can affect our health in many unwanted ways, depending on which active ingredient the mothballs contain. Adults exposed to naphthalene or paradichlorobenzene vapors for short periods, for example, may experience nausea, dizziness, headaches and/or vomiting. Longer exposure has been linked to the development of hemolytic anemia, as well as kidney and liver damage. Naphthalene, according to the World Health Organization, may also cause cancer.           

Young children exposed to mothballs containing either pesticide can develop fever, diarrhea and abdominal pain, especially if they have eaten them. Dogs who ingest naphthalene mothballs may become lethargic or experience diarrhea or tremors. Paradichlorobenzene mothballs have been linked to kidney and liver damage in pets. Need more information to help convince your neighbor to stop using mothballs? Check out the National Pesticide Information Center’s website:

Recycling plant pots 

There are a lot of things to love about gardening, but all the waste that goes with it isn’t one of them. Yes, I’m talking about plant pots. Unless you buy plants in compostable or biodegradable pots, you end up with a whole lot of plastic that needs to go somewhere. Many garden centers used to accept plastic plant pots for recycling, but most don’t anymore for various reasons, including the fact that many cities now accept plant pots for recycling.

In Minneapolis, plastic plant pots labeled #1–#7 can be put in our blue recycling bins. Just be sure to rinse them off so the dirt doesn’t cause problems during processing. Hanging baskets usually aren’t recyclable but rather than throwing them in the trash, I’ve started reusing them every year. One way to do that is to remove the wires and replant them with annuals to add a bit of color here and there in the garden. Or, just reuse them as hanging baskets by buying a bunch of annuals and creating your own arrangements. Going that route is a heck of a lot cheaper than buying pre-planted baskets.

Biodegradable pots 

Lots of people are studying ways to create pots that will break down naturally on their own rather than needing to be recycled. And that’s a good thing because research has shown that many of the current pots being billed as biodegradable do break down, but not fast enough for plant roots to get through them when they need to. If you buy plants in biodegradable pots, I’d recommend slipping the plant out of the pot before planting. You can rip the pot up and add it to your compost pile. If roots are already sticking out of the pot, soak the whole thing in water and then gently tear off pieces from the side and bottom of the pot to help the roots grow freely in the ground.

Check out Meleah’s blog — — for more gardening tips or to email her a question or comment.