The Male Fern (Dryopteris filix-mas) actually gets its name from an old folk belief that eating it could cure tapeworms. Spoiler alert: don’t try that at home! The plant contains toxins that are just as nasty for the human nervous system as they are for parasites. However, there’s a silver lining for us gardeners—that same toxicity makes it a fantastic, all-natural weapon against slugs and snails.
Slugs give Male Fern a wide berth
Slugs seem to have a sixth sense when it comes to the toxins in Male Fern. It’s the only way to explain why they avoid this plant like the plague. Because they won’t go near it, this fern is one of the best organic tools you have to stop those slimy pests from munching on your prize hostas or veggies.
Every part of the plant works
Since it is toxic, you might not want to intentionally plant it in your flower beds, especially if you have pets or kids. But once you know its key characteristics, it’s pretty easy to spot growing wild. Both the roots and the fronds (the leaves) work for pest control, but the fronds are much easier to use since you don’t have to do any heavy digging.
Brewing a fern “tea” (Liquid Manure)
While you can just scatter fronds around the garden, you’ll get much better results by brewing a fermented liquid manure. It’s a bit smelly, but it works wonders! Here’s how to make your own batch:
- Fill a bucket or a large container with water.
- Add your fresh or dried Male Fern.
- If using fresh fronds, chop them up first; if using dried, crumble them into the water.
- Cover the container with a mesh screen or a cloth (to keep bugs out but let it breathe).
- Give the mixture a good stir once a day.
A few pro tips
For the perfect ratio, aim for about 2 pounds (1 kg) of fresh chopped fern for every 2.5 gallons (10 liters) of water. If you’re using dried fern, you only need about 5 ounces (150 grams) for that same amount of water. Let the mixture ferment for about two weeks. Once it’s ready, just spray or pour it in a protective circle around the plants you want to save from the slugs.
