Comptonia peregrina (Sweet Fern)


The use of common names can often confuse rather than instruct someone to a plants nature, this is definitely the case with sweet fern. Contrary to the name, sweet fern is not a fern and after exploratory chewing, is not sweet. To further exemplify the point, Comptonia is also know as meadow fern, shrubby fern, sweet bush, ferry bush, Canadian sweet fern, and spleenwort bush. However, as the leaves of Comptonia are fern-like and upon bruising the leaves emit an aromatic hay-like smell, perhaps the name of sweet fern is not hopeless.

Comptonia, unlike ferns in our climate, is a woody shrub which can grow up to four feet in height, although two to three is most average. It has long and thin entire and indented deciduous leaves which emerge early in spring with little fall color. As with other plants in the Bayberry family (Myricaceae) it is stoloniferous and thereby spreads by underground shoots to eventually form a thicket of growth. It is native from Nova Scotia to North Carolina and is frequently found in the sandy oak woods of eastern Long Island as it is throughout its range.  In our area Comptonia is often found in the company of Kalmia latifolia (MountinLaurel) and Vaccinium angustifolium (Low Bush Blueberry) to form our most common understory of the forest floor. Comptonia, as a zone 2 plant, is extremely cold hearty where found.

Attempts at transplanting Comptonia often leads to a very low survival rate, if the plants have to be moved, early spring moving is best providing you provide a large root ball and dig at the time of bud break but before leaf emergence. A far superior method to collecting wild material is either thru purchase of nursery stock or propagation of the plants yourself. If nursery material is purchased, the container plants move quite easily once the roots leave the confines of the pot. Propagation is done from root cuttings, stem cutting and seed. The seed germinates easily but Comptonia has sparse production and finding a large quantity is often difficult. The seed is found inside of a small spike covered shell that is often overlooked. Sources note that firm stem cuttings taken in June root with high percentage. My favorite method of Sweet Fern production is done by root cuttings taken just prior to bud break, when the buds begin to swell. Roots are dug, washed to remove all soil and cut 1/8” pencil thickness  and 2-4” long. The root segments are placed horizontally in trays of sterile, well drained potting medium and covered to a depth of ¼”. The trays should receive bottom heat to 70 deg. And after 2-3 weeks leaf initials will appear on the cut ends along with some root growth. After plants have grown sufficiently they can be potted but are venerable at this stage, if you are going to suffer losses it will be at this point, once the plants establish enough to fill a 3” pot they harden off enough to handle easily.

click photo to enlarge

Comptonia can be used in so many ways it is surprising that it has not found wider acceptance. Most of our work involving Comptonia is done in native gardens or conservation projects (where it forms thickets to stabilize hillsides on sandy sites). In situations of native work the plant works well but can hardly show off its fine attributes. Grown as a massing groundcover, Comptonia makes a beautiful glade through which large conifers can be planted. The sweet fern leaves have a delicate appearance which can show off specimen evergreens or soften a hard wall or other structure. Plantings at gates, entrances, walkways or high traffic areas allow the leaves to be bruised which give off its aromatic smell, the same hold true for its use in fragrance gardens. Bulky leaved plants, as Hydrangeas, can be softened by Comptonias delicate leaf form and will often spread through the planting to create a spontaneous effect.

In situations where dry shade prevails, Comptonia has few rivals. An established clump will survive the worst of droughts in poor soil with little to no additional irrigation. Native stands routinely pass through yearly droughts with no care looking excellent throughout the season.  Dry shade areas can be planted with a mixture of Comptonia, Kalmia latifolia, and Gaulthera procumbens (Wintergreen) to create a beautiful, tough year around landscape that once established will require no maintenance.

Dune Plants Homeindex.htmlshapeimage_3_link_0
Dune Plant Survival & Supremacyplantsurvival.htmlshapeimage_4_link_0
Perennials & Grasses - Woody PlantsPerennialsGrasses.htmlshapeimage_5_link_0
Carex pensylvanicaCarexpensylvanica.htmlshapeimage_6_link_0
Beach PlumBeachPlum.htmlshapeimage_7_link_0
Comptonia peregrina (Sweet Fern)shapeimage_8_link_0
Hudsonia-Arcostaphylos AssociationHudsonia.htmlshapeimage_9_link_0
Winter SeasonWinterSeason.htmlshapeimage_11_link_0