Sweet Fern

Comptonia peregrina

Description & Overview

Sweet Fern, despite its name is not actually a fern (or a perennial). Sweet Fern is a Wisconsin native shrub with aromatically pleasing foliage, especially when its leaves are crushed; this poses a great investment for wildlife and landscape use. Great for slopes and erosion-prone areas, or dry nitrogen-deprived sites, Sweet Fern will adapt and thrive. When left alone to colonize it forms a beautiful fern-like mass with its pleasing to the eye deeply cut and notched foliage. Looking to bring in the butterflies to your yard? You’ve found your answer!

Core Characteristics

Mature Height: 2-4 feet
Mature Spread: 4-8 feet
Growth Rate: Moderate
Growth Form: Low-growing shrub, spreading, rounded massing habit
Light Requirements: Full Sun to Partial Shade
Site Requirements: Prefers sandy, well drained soils. Tolerant of moist soils but does not like heavy clay.
Flower: Inconspicuous greenish-yellow to brown catkins
Bloom Period: April – June
Foliage: Fragrant, simple, narrow and deeply notched dark green fern-like leaves
Fall Color: Turns brown in fall and persist through winter
Fruit Notes: Small nut enclosed in bur-like husk

Suggested Uses:

This deer-resistant, Wisconsin native is perfectly fit for a range of soil conditions and landscape uses. A host for caterpillars and larvae, place this low-spreading shrub at the border of a pollinator or rain garden. Its ability to tolerate dry sandy and moist soils makes it an easy fit. Roots of the Sweet Fern can fix nitrogen in the soil so the growth can be strong in nearly sterile sandy soils. Heat, drought, and slight salt tolerance make Sweet Fern an excellent choice for amassing along your foundation, alleyways, or driveway. However, Sweet Fern will not tolerate heavy clay. Allow Sweet Fern to mass on slopes or banks to create a thicket that can prevent erosion. Provide full sun to part shade, and with its suckering habit it is sure to fill in space in no time.

Wildlife Value:

A native Wisconsin shrub, Sweet Fern is an important host for an array of butterfly and moth larvae, including the Io moth, several Sphinx moth species, and the Gray Hairstreak butterfly. Additionally, it is a caterpillar host plant for the Anise Swallowtail butterfly.

Small, inconspicuous catkins that give way to bur-like nutlets attract birds and butterflies, making Comptonia peregrina a perfect addition to a pollinator garden. And when left alone to colonize, Sweet Fern creates a cohesive relationship with insects that are so vital to our ecosystems’ basis.

Maintenance Tips:

A vigorous plant when left alone, Sweet Fern should be sited where it can be allowed to colonize. Tolerant of a wide range of soils, little maintenance, and watering are required. Sweet Fern is adaptable and can handle occasional drought, if summer is particularly dry, take some time to water your naturalized area of Comptonia peregrina infrequently. If a landscape site is chosen per our recommendations, this shrub should bring almost no maintenance into your gardening routine.


Sweet Fern has no significant insect or disease pests. However, it can transplant poorly. Once established, it will spread rapidly.

Leaf Lore:

When crushed, its leaves give way to a sweet smell! With fern-like foliage, this gives its common name. Belonging to the Bayberry (myricaceae) family, Sweet Fern’s genus name (comptonia peregrina) honors a patron of botany, dendrologist, and most famously Bishop of London, Henry Compton (1632-1713).

Small inconspicuous green-yellow flowers form in clusters that are separate female and male, on the same or different plants.

Sweet ferns leaves have been known as folk medicines or as seasoning.

Companion Plants:

Using Sweet Fern as an understory plant, combine with a large native shrub or tree like Musclewood, Appleleaf Serviceberry, or Pagoda Dogwood. To create a naturalized garden, use other native plants like Prairie Dropseed, Wild Bergamot, Prairie Smoke, or Sky Blue Aster in dryer sites. If you utilize it’s ability in a rain garden or near a marsh, choose water loving companion perennials like Red Milkweed, Joe-Pye Weed, or Cardinal Flower.

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