I'm hand edging my lawn!

Last week I went to the hardware store and explained to the gardening specialist that I wanted to edge my lawn. But not just to the edge of the concrete that surrounds it on three sides. I wanted to cut away about an inch-or-so of grass from between the sidewalk and concrete paths leaving a dirt border. I thought he would suggest one of the tools below:

Examples of a manual spade (left) and rotary (right) lawn edgers.

But because the walkway leading up to our house is curved he encouraged me to get down on the ground and use a utility knife. Like the kind people use as box cutters. "It'll be the cleanest edge you can get," he said.

So I did.

Immediately I was grateful for his suggestion as I realized that using a spade or rotary cutter would have resulted in a lot of collateral damage killing earthworms, roly poly bugs, snails and slugs that live in our yard. I carefully parted the lawn and moved all of little bugs I spotted out of the way, before slashing through the grass roots with the razor blade.

And then I spotted a worm unlike any worm I'd ever seen before.

It was very thin, with an odd triangular shaped head, and was super slippery and shiny looking. I found two of them and set them aside just like all of the other bugs. Later, I searched triangular+head+worm on Google and learned that they were predatory, non-native, earthworm killing Hammerhead Flatworms. Oh no! So they are not beneficial bugs and the only thing they eat are earthworms which we all know are some of the most helpful bugs in any garden.

The Hammerhead Flatworms were introduced to the United States through plant nurseries by being transported in the soil of potted plants. The two I saw were each around an inch long but they can grow as large as 20" long!

A Predatory Worm: The Hammerhead Flatworm

Now I feel torn. I don't believe in killing bugs except for fleas and mosquitos since they carry diseases like the Plague and West Nile Virus. But I love earthworms and the flatworms are an invasive species that shouldn't be here.

Every article I read online says you should kill them when you find them. But you can't smash or cut them into pieces because each fragment will simply grow into a new flatworm. So, if you cut a single flatworm into 10 pieces you'll end up with 10 complete flatworms. Weird. Most say to melt them with citrus oils or salt.

I don't have the heart to do that. I'd like to find a more humane way to kill them than basically burning them in an acid bath. I'm wondering if drowning or freezing them would be more humane. If you have any experience with the least cruel way to kill a Hammerhead Flatworm please leave a suggestion in the comments below. I'd appreciate your insights.

Before

Back to my lawn. It's coming along. I've worked on it for short sessions (it's kind of back straining) over several days and it already looks like this along the curved walk side. It's coming along and I'm optimistic that it's going to look great when I finish all four sides. I'll keep you posted when I get it done.

After