Mt Cuba Center
Mt Cuba Center
Back to News Press Release – January 17, 2023

Press Release

Carex as Problem-Solving Perennials

According to a four-year trial conducted by Mt. Cuba Center in Hockessin, Delaware, Carex, also known as sedges, are one of the most effective and versatile problem-solving plants for home gardens. The trial evaluated 70 types of Carex including 65 species and five cultivars native to the mid-Atlantic region. Results are available now in the new report, Carex for the Mid-Atlantic Region. Carex can be found in a wide range of habitats and provide food and shelter for wildlife, as well as being a sustainable alternative to traditional turfgrass lawns.

Carex woodii in the Mt. Cuba Trial Garden

Sam Hoadley, Mt. Cuba’s manager of horticultural research, ranked the species and cultivars based on plant vigor and foliage quality in both sun and shade locations. Carex woodii, or Wood’s sedge, was the top performer in the trial, demonstrating the genus’s ornamental value and versatility in the garden. It excels in both sun and shade and offers a carpet of straw-colored flowers from April to May. “Carex are quickly becoming favored by homeowners and horticulturists alike, thanks to their beauty, utility, and overall minimal maintenance requirements,” explains Hoadley. “The diversity of the genus is outmatched only by the wide spectrum of habits in which they grow—from shady wetlands to coastal dunes, you can find a Carex to grow and thrive there.”

Carex bromoides from Mt. Cuba Center Trial Garden research.

Hoadley adds that not only do Carex provide food and shelter for wildlife, but they also proved to be an option for those looking to replace their lawn with a more sustainable option.“How many perennial genera have members that we can recommend as successful and mowable replacements for traditional turfgrass lawns? That aspect alone pulls Carex into the long-term sustainability conversation,” he says.


Key Takeaways:

  • Carex woodii, or Wood’s sedge, was the trial’s top performer and exemplified the genus’s ornamental value and versatility in the garden. Although similar to pensylvanica in its low-growing, slow-spreading habit, C. woodii forms a denser mat of foliage, and is therefore, superior to suppressing weeds. It excels in both sun and shade locations and offers a carpet of straw-colored flowers from April through May.
  • The trial’s top-performing species and cultivars thrive in average soils; i.e., their trial conditions were not considered too moist or too dry. But do not dismiss those without high marks as “underperformers.” These may, in fact, excel in landscapes with differing soil types. Those considering Carex species in their landscapes are encouraged to consult the “Carex for Dry Soils” and “Carex for Moist-to-Wet Soils” charts in the research report.
  • The Carex trials included a yearlong mowing component and found a vast majority of types trialed were tolerant of regular mowing. Small- to medium-sized Carex with fine-textured foliage gave the aesthetic most closely associated with that of a traditional lawn. Those species with horizontally growing underground roots show potential to fill in gaps within a lawn, as well as require fewer plants when installing a Carex lawn from scratch. woodii, the trial’s top-performing Carex, is also the trial’s top-performing mowable sedge. Find the other top mowable sedges listed in the research report.
  • While most Carex are wind-pollinated with little value for pollinators, Carex provide for other wildlife in a variety of ways. The seeds of Carex are eaten by mammals and birds and the leaves of Carex of consumed by caterpillars of numerous species of butterflies and moths. In some cases, the Carex themselves are the habitat, providing refuge for a diversity of organisms, both in home gardens and in the wild. Mt. Cuba is working with the state of Delaware to help expand suitable bog turtle habitats, and stricta is playing an important role as part of the turtles’ habitat.

This research report details Mt. Cuba’s top 16 Carex performers. Descriptions of all 70 plants included in the trial are available at