What Is Japanese Sedge ?
Japanese sedge (Sedum sp.) is a perennial herbaceous plant native to Japan and Korea. It grows up to 2 m tall with a spreading habit. It has small green leaves which are arranged in two lobes at the top of the stem. They have five leaflets each, three on each side of the leaflet and one above it. There are several species of Japanese Sedge. Some are called ‘longleaf’ because they grow only to 6 cm or 2 ft high and have very long leaves, while others like the ‘shortleaf’ ones have short leaves but a shorter height than the other varieties. The name comes from its resemblance to the sakura flower.
The flowers appear in spring and summer when there is plenty of moisture in the soil and warm weather. The petals are yellow, white, pink or purple. Flowers are followed by seeds that germinate in 3 days.
Seeds usually float away after a few days so they do not harm your garden. Japanese Sedge has many uses including food, medicine and ornamental purposes.
How To Grow Japanese Sedge?
Since the roots grow to over a foot long, it is best to plant them in a container rather than directly in a garden. The container should have several holes for drainage. It grows fastest when planted in fertile organic soil with good drainage and sun. When grown in the ground, it can reach up to 2m tall, but in a container it can reach a foot or two. Watering well when it is hot will produce lush green foliage and flowers. Like all plants, it prefers rich organic soil. It can tolerate most conditions apart from cold and drought so it is very easy to maintain.
In spring, it should be given a balanced fertilizer and it should be provided with at least an hour of direct sunlight each day. It also prefers cool nights so it should be protected from strong winds. It has weak stems so it should not be trampled on or it will break.
It can also be propagated by division or cuttings. It grows slowly and it is easily damaged so it is best to keep it in a container to protect it.
In late summer, leaves will start to turn brown and should be removed to make the plant stronger for the next growing period. If left they will attract pests and become susceptible to rotting. It will survive mild frost but it is best to protect it from strong freezing winds as the stems are weak.
The leaves are very durable and can be used for many purposes. It was once cultivated for fodder and the stems used for hats, roofing and rope.
Harvesting Japanese Sedge
Japanese Sedge has over 40 different types, including dwarf types that only reach a height of 6 inches, up to 3 feet and the tall varieties such as ‘Aureomarginata’ reaching from 1 to 3 meters. It is also available in green, pink and white varieties.
The leaves of this plant can be harvested at any time of the year but the best time to harvest them is between May and September when they are full size. As with many other perennials, it is better to cut them back after they have flowered before they go to seed as this promotes new growth and a healthier plant. The flowers themselves can also be picked and used in floral arrangements.
The leaves of this plant can be dried, used fresh or used as is. They have a coarse texture so the smaller varieties are better for eating. The large varieties are more suitable for cellulose purposes such as insulation, packing and padding as well as animal feed.
Japanese Sedge Interesting Facts
This plant is also known as ‘Ribgrass’ because the stems are ribbed or grooved which distinguishes it from other sedges.
The stems of this plant can grow quite large, up to 3 inches in diameter and are used for thatching and wall thatching. It is also woven into baskets.
A chemical in this plant (Sedolin) prevents the blood from clotting so it was once used as a bleeding agent for nosebleeds and other medical purposes.
This is one of the fastest growing plants in the world and can grow over a foot a day!
Japanese Sedge is acutally not a grass but a sedge which is a type of grass that looks like a flower.
The leaves of the plants can be eaten by livestock and the plant itself is free feed so it is often grown to help support grazing animals such as goats, deer and rabbits.
This plant was also used for thatching and making ropes and fabrics before cotton became more readily available.
The dried leaves were also used as a tea substitute during the American War of Independence.
This plant was once called ‘Lunaria’ which means ‘moon child’
Other names for this plant include: small cat’s tail, goat’s tail, big bunny ears, old man’s whiskers and Cushion Grass.
Japanese Sedge is not related to the true Sedge (genus: Carex).
The tall varieties of this plant were often cultivated by the American Indians to make into rafts.
The flowers on this plant are considered edible but they have a very bitter taste. They can be eaten as an emergency food, though they should be combined with a starchy food such as rice or any other grain product as they are not very nutritious when eaten alone. The plant itself is not poisonous but some people may suffer from allergic reactions to it, similar to pollen allergies.
Japanese Sedge is an invasive plant in some areas and is slowly taking over parts of North America.
The seed heads are sometimes used for ornamental purposes as they turn bright orange or red in the fall.
The dried leafy stems were traditionally used as fish traps by Native American tribes.
The stems of this plant contain a yellow dye that can be used for coloring clothing, hair or fur. It can be combined with other natural dyes to create new colours.
The plant itself does not have much of a scent but it can often be found growing with other plants that do have a scent such as wild carrot, mints and others, which means if you are gathering herbs for scent then you often gather Japanese Sedge as well.
Sources & references used in this article:
A new strain of Arthrinium phaeospermum isolated from Carex kobomugi Ohwi is capable of gibberellin production by SA Khan, M Hamayun, H Kim, H Yoon, J Seo… – Biotechnology …, 2009 – Springer
Effects of light quantity and quality on growth and reproduction of a clonal sedge, Cyperus esculentus by B Li, T Shibuya, Y Yogo, T Hara… – Plant Species …, 2001 – Wiley Online Library
Effects of sedge and cottongrass tussocks on plant establishment patterns in a post-mined peatland, northern Japan by A Koyama, S Tsuyuzaki – Wetlands Ecology and Management, 2010 – Springer
Estimation of the Genetic Composition of a Near-Threatened Tidal Marsh Plant, Carex rugulosa, in Japan by K Ohbayashi, Y Hodoki, H Kunii – Wetlands, 2012 – Springer
Comparisons of nutrient recovery and specific leaf area variation between Carex lasiocarpa var. occultans and Carex thunbergii var. appendiculata with reference to nutrient … by K Onimaru, K Yabe – Ecological Research, 1996 – Wiley Online Library
Long-term persistence in a changing climate: DNA analysis suggests very old ages of clones of alpine Carex curvula by T Steinger, C Körner, B Schmid – Oecologia, 1996 – Springer
Shoot population dynamics of Carex kobomugi on a coastal sand dune in relation to its zonal distribution by SI Ishikawa, N Kachi – Australian journal of botany, 1998 – CSIRO
Dissemination of Carex albata Boott seeds by grazing cattle by N WATANABE, A NISHIWAKI… – Japanese Journal of …, 2002 – jstage.jst.go.jp
Carex kobomugi Owhi, an adventive sedge new to New England by LA Standley – Rhodora, 1983 – JSTOR