Hay scented fern and boulder fern are common names for Dennstaedtia punctilobula, a popular fern species belonging to the family Dennstaedtiaceae. It is known for its light green, lacy, triangular leaves, normally referred to as fronds. This fern is deciduous, shedding its leaves upon maturity. It is native to eastern and northeastern North America and thrives in open woods. This plant is called hay scented fern because it smells like hay or freshly mowed grass when the fronds are crushed.
The fronds are typically 12 to 18 inches (30 to 45 cm) long and 4 to 12 inches (10 to 30 cm) wide, being widest at the bottom. Sometimes confused with the New York scented fern, which has tapering fronds, the fronds of the hay scented fern are identified by their triangular-shaped leaflets located at the bottom of the plant. The plant comes in varying shades of light green, and spores can be found on the underside of the fronds. These fronds tend to grow toward the direction of strong sunlight, so the pattern of growth in a colony of hay scented ferns depends on the location of their light source.
This type of fern can be used as an inexpensive and fast-growing ground cover for expansive areas, providing a carpeted appearance. It is also often used in woodland gardens, water feature enhancements, and as a border along pathways. Either standing erect or arching, the fronds of the hay scented fern are a popular choice by many gardeners.
The fronds of the hay scented fern turn golden during fall. They are frost-tolerant, and even when the fronds shed during winter, they quickly grow back during spring. This perennial plant divides in the spring and grows in colonies or patches rather than individual clumps. Propagation can be done by dividing the underground stem, known as a rhizome in botany, which sends out roots and new stems.
Hay scented ferns thrive in the moist and damp conditions of woodlands or in dry, acidic soils in partially sunny areas. This fern is usually considered easy to cultivate and can tolerate more sun if the soil’s moisture level is maintained. The plant is drought-tolerant and can tolerate salt spray, so it is a popular addition to seaside gardens. This particular plant is known to grow in environments where many other plants fail to thrive; however, slugs and snails are problematic for this type of fern, as they feed on the plant and can severely damage it in the process.