Carex

carex

( KAY - reks )

At-A-Glance Information

This large genus of grasses, also known as Sedges, are commonly grown as foliage effect for borders, rock gardens, containers, and even water gardens. In addition, they are useful as groundcovers and for erosion control. They need full sun to partial shade, and have varying water needs depending on the species grown. These grasses are mainly evergreen, and can take on bronze tones in cooler temperatures.

carex Species and Varietals

Carex is a genus in the plant family Cyperaceae and includes over 2,000 species. The best growing zones for these grasses vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Carex barbarae (Santa Barbara Sedge, Valley Sedge, White Root)
This species grows well in USDA hardiness zones 7-9 or Sunset growing zones 4-9 and 14-24, and is native to coastal areas in Oregon and southern California. Leaves are green, and form a clump about 1-3 feet tall. Great for covering large, damp swaths of land and used for erosion control. Spreads farther the more water it receives; supply moderate amounts of water for best results in the landscape.

Carex buchananii (Leather Leaf Sedge, Curly Top Sedge, Buchanan's Sedge, Fox Red Curly Sedge)
These grasses are great in UDSA hardiness zones 5-9 or Sunset growing zones 2b-9 and 14-24 and are native to New Zealand. Blades have curled tips, and foliage is copper to brown. Great as an accent or in a container. Needs moderate water to perform well. Individual tufts of grass reach between 1 and 3 feet tall when mature. This species is considered invasive in the western United States.

Carex comans (New Zealand Hair Sedge, Mop-Headed Sedge, Hairy Sedge)
This species does well in USDA hardiness zones 7-10 or Sunset growing zones 2b-9 and 14-24, and is native to New Zealand. These grasses form clumps to a foot tall with narrow, silver-green foliage. Variety 'Bronze' has copper-brown leaves. Can be invasive in moist areas, especially in Tasmania, Australia.

Carex divulsa (European Gray Sedge, Grassland Sedge, Berkeley Sedge)
This species is best in USDA hardiness zones zones 2b-9 and 11-24 and is a popularly grown selection from Europe. Leaves are dark and green, forming clumps 1.5 feet tall and 2 feet wide. Flowers are greenish, appearing on spikes in wintertime through spring. Great as a groundcover, and competes well with surface roots of trees and shrubs. Great with moderate water and full sun or shade. Requires more irrigation in warm areas. This species is considered invasive in California, Oregon, Washington, Argentina, Australia, and New Zealand.

Carex elata (Tufted Sedge, European Tussock Sedge)
This species grows in USDA hardiness zones 5-9 or Sunset growing zones 2-9, 14-19 and 22, forming a clump 2.5 feet tall and 1.5 feet wide. Plants will die back all the way in wintertime, and need ample moisture and winter chill to perform well. Cultivar 'Aurea' ('Bowles Golden') has bright yellow new foliage that matures to greenish yellow.

Carex flacca (Carex glauca) (Blue Sedge)
This species is best in USDA hardiness zones 4-9 or Sunset growing zones 3-9 and 14-24, and is native to Europe. This blue-grey creeping grass reaches between 6 inches and 2 feet tall and wide, and is evergreen (except in the coldest climates). Spreads slowly, and can be used as a lawn, in between stepping stones, and as filler. 'Blue Zinger' is a popular cultivar. Can tolerate many soils and does best with moderate water. This species is considered invasive in parts of eastern North America.

Carex flagellifera (Weeping Brown Sedge, Coffee Twist Sedge, Glen Murray Tussock Sedge, Auburn Cascade Sedge, Bronze Hair Sedge)
This New Zealand native grass does well in USDA hardiness zones 7-9 or Sunset growing zones 4-9 and 14-24, and has 2-foot long red leaves. Often short-lived, this species needs regular to moderate water and has many varieties to choose from. This species of Carex is considered to be invasive in parts of Tasmania and Australia.

Carex morrowii (Japanese Sedge, Morrow's Sedge, Japanese Grass Sedge, Kan Sedge, Everglow Sedge)
Native to Japan, this species is best in USDA zones 5-9 or Sunset growing zones 3-9 and 14-24, and reaches a foot tall and a little wider. Foliage is medium green. Great for edging or planting in rock gardens, also good amongst stepping stones. Needs regular water. Varieties include 'Goldband' (with creamy margins), 'Fisher's Form' (with leaf margins in cream-yellow), 'Ice Dance' (pictured; with dark green leaves that have cream margins) and 'Variegata' (with white-edged foliage).

Carex muskingumensis (Palm Sedge)
Native to North America, best in USDA hardiness zones 4-9 or Sunset growing zones 4-9 and 14-24. Not commonly grown, this Sedge reaches 2 feet tall and spreads widely by rhizomes. Green leaves radiate from stems, and foliage turns copper before going dormant in wintertime. This species needs regular water. Varieties include 'Little Midge' (to 10 inches tall), 'Oehme' (pictured; solid-green foliage that develops a gold margin with maturity).

Carex oshimensis (Japanese Sedge, Evergold Sedge, Everillo Sedge, Oshima Sedge)
Japanese native that does well in USDA hardiness zones 5-9 or Sunset growing zones 3-9 and 14-24. Individual plants reach 1-2 feet tall and 2-3 feet wide at maturity. Needs partial to full shade and regular water to perform well in the garden. 'Evergold' (pictured) is a very popular cultivar with cream foliage that has green margins.

Carex pansa (California Meadow Sedge, Sand Dune Sedge)
Native to California, this Sedge is best in USDA hardiness zones 7-10 or Sunset growing zones 7-9 and 11-24, and forms a dark green mat 6-8 inches tall. Moderately tolerant of foot traffic, this species is great as a lawn alternative, in meadows, in between pavers, and as accents in rock gardens. Needs moderate water when established, and is sensitive to overwatering.

Carex phyllocephala (Sparkler Palm Sedge)
Best in zones 4-9, 14-19 and 22, and is a variety of a Chinese species. To 1-2 feet tall and slowly spreading, reddish-purple stems are topped with spiraling dark green leaves with white variegation. Goes dormant in wintertime. Great as a groundcover or in containers, and leaves can be used in cut flower arrangements. Great for shaded border areas and performs best with some winter chill. Needs regular water. Cultivar 'Sparkler' (pictured) is a popular garden ornamental. This species is considered to be invasive in North Carolina.

Carex spissa (San Diego Sedge)
Best in USDA hardiness zones 8-10 or Sunset growing zones 7-9, 14-17, and 19-24. This species likes boggy conditions and is native to Southern California. Plants form a slowly spreading clump of silvery grey upright foliage 3-4 feet tall. Flowers are light gold-brown and bloom in clusters in spring. Needs ample water, and can even grow in standing water.

Carex testacea (Orange New Zealand Sedge)
Native to New Zealand, this species grows well in zones 4-9 and 14-24. Clumps have an arching habit, and are olive-green and orange, depending on how much sun or shade the plant gets. Can self-seed and spread in moist locations. Needs moderate water to regular water, and is often short-lived. This species is considered invasive in Australia.

Carex texensis (Carex retroflexa texensis) (Catlin Sedge, Texas Sedge)
This species of Sedge does well in USDA hardiness zones 5a-9b or Sunset growing zones 7-9 and 11-24 and is native to the southwestern United States. Leaves are medium green and drooping, forming a wavy carpet of foliage. Great as a small-scale lawn or groundcover, and is also included in grass mixes. Trim to remove seed heads to discourage reseeding. Needs partial to full shade and regular water to perform well in the garden.

Caring for Carex

Plant Carex in a space in the landscape that receives partial to full shade or full sun; ideally, they appreciate around 6 hours of sun to grow well. Sun exposure requirements vary depending on the species grown, however, so make sure to check the plant label before choosing a planting site. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 5.5 and 7.5 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants perform well in consistently moist soils; there are even some species that can handle boggy conditions, doing well along the edges of ponds or streams.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants and encourage reblooms. Carex can also be used as a lawn grass and mowed to a height of 4 inches. Carex plants have a clumping habit, and will spread over time. If growing Carex in a cramped space like a narrow border, make sure to divide plants every few years to ensure ongoing health. For instructions on how to successfully divide a Carex plant, see the Propagation section below. Carex plants are considered short-lived to long-lived perennials depending on the species. They can persist for years, sometimes even decades, in the landscape before needing to be replaced.

Propagation

Carex, or Sedge, can be propagated either by dividing existing plants or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Carex, follow the instructions below:

Propagating Carex by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. They are held on spiked inflorescences above the foliage. Once they have dried out and begun to split open, harvest the seeds. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Carex by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost, and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the rhizome roots. Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick rhizome section with two or three buds.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divided rhizomes about an inch under the soil surface and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout.