Pest identification
What's eating my new york fern?
Slugs and snails
Signs: Holes or stripped sections on soft new fronds in spring; established fronds are largely left alone as they toughen
Control: Apply iron phosphate slug pellets or slug-specific nematodes in early spring; remove debris and leaf litter where slugs overwinter; hand-pick after rain or at night
Scale insects
Signs: Hard tan or brown bumps on frond stipes and rachis; heavy infestations cause frond yellowing and poor vigor
Control: Scrub off with a soft brush and soapy water; apply horticultural oil spray; remove heavily infested fronds at the base to reduce spread
Caterpillars
Signs: Moth larvae chew holes or entire sections from frond pinnae during summer; multiple moth species use native ferns as a host
Control: Hand-pick caterpillars and egg masses; encourage insectivorous birds; apply Bacillus thuringiensis (Bt) spray if infestations are heavy
Keep new york fern pest-free
Healthy plants resist pests best. Get the basics right:
New York Fern pests — FAQ
What is eating my new york fern?
New York Fern (Thelypteris noveboracensis) is a native North American woodland fern with very few serious pest problems. Slugs can occasionally damage soft new growth. Scale insects may appear on stipes. It is notably deer resistant. Its spreading rhizomes allow rapid regrowth after minor pest damage, making it one of the most low-maintenance ferns for shaded gardens.
How do I get rid of slugs and snails on new york fern?
Holes or stripped sections on soft new fronds in spring; established fronds are largely left alone as they toughen Apply iron phosphate slug pellets or slug-specific nematodes in early spring; remove debris and leaf litter where slugs overwinter; hand-pick after rain or at night
How do I get rid of scale insects on new york fern?
Hard tan or brown bumps on frond stipes and rachis; heavy infestations cause frond yellowing and poor vigor Scrub off with a soft brush and soapy water; apply horticultural oil spray; remove heavily infested fronds at the base to reduce spread
How do I get rid of caterpillars on new york fern?
Moth larvae chew holes or entire sections from frond pinnae during summer; multiple moth species use native ferns as a host Hand-pick caterpillars and egg masses; encourage insectivorous birds; apply Bacillus thuringiensis (Bt) spray if infestations are heavy