How to Kill Ferns

Eradicate ferns with careful use of a herbicide.

Herbaceous ferns often grow energetically throughout the understory of shaded areas of a landscape. Ferns reproduce with spores, which germinate and grow into new fern plants with underground rhizomes. If ferns become too prolific, you might have to kill them to eradicate them from your growing area. With careful use of glyphosate herbicide, you can clear the area of the ferns you wish to remove.

Things You'll Need

• Cardboard or tarp
• Glyphosate spray (labeled for home use)

Instructions

1. Cover any surrounding plants that you do not wish to harm with sheets of cardboard or a tarp to prevent the glyphosate spray from touching these plants as you spray it.

2. Spray the glyphosate onto the ferns you wish to kill. Cover the fronds evenly, but do not spray them to the point where the glyphosate liquid drips off the plants.

3. Watch for indications that the glyphosate spray is beginning to kill the ferns. You should see the fronds yellowing and withering in as little as six hours. Within one to two weeks, the ferns should be dead.

4. Reapply the glyphosate to surviving ferns if they still appear to be growing in the landscape after two weeks.

5. Pull the dead ferns from the soil and discard them.

Tips & Warnings

• The Roundup label indicates that you can plant new plants in the growing area as soon as one to three days after applying glyphosate. If the ferns die successfully within this period, pull the dead plants and place new plants in the soil.

• Apply glyphosate on a sunny day when the temperature is from 60 to 80 degrees Fahrenheit for the best results. Avoid using glyphosate on a windy day because the wind could carry the spray onto desired plants.

• Apply glyphosate on ferns while they are growing energetically for best results.

• Wear protective clothing while you apply glyphosate, including long pants, long sleeves, closed-toe shoes, gloves and eye protection to prevent spray from contacting your skin and eyes.

• Keep people and pets away from the application area until the glyphosate spray dries.

References

• Scotts: Roundup Weed and Grass Killer Label
• National Gardening Association: Glyphosate Herbicide
• "Bracken and its Management"; Bob Taylor, et al.; 2003 (P. 41)
• Northern Woodlands; Got Fern? Controlling Native Invasive Plants; Irwin Post; August 2010