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A picture of a Sea-Urchin Grass

Sea-Urchin Grass

Cyperus rotundus

Also known as

Purple Nutsedge, Coco-Grass, Java-Grass, Ground-Almond, Nut Sedge, Nut-Grass, Purple Nut-Grass

Cyperus rotundus at Kadavoor by Jeevan Jose (CC BY-SA 4.0)

Full Sun
Easy care
Moderate watering
Frost Hardy


RHS hardiness


Minimum temperature

Expected size









  • spring
  • summer
  • autumn
  • winter

This plant has no fragrance

More images of Sea-Urchin Grass

A photo of Sea-Urchin Grass
A photo of Sea-Urchin Grass

Sea-Urchin Grass Overview

Nut-grass is an extremely tough weed, very strong in structure and very difficult to erase. It has triangular shaped thick stems, topped with three leaves, the root system is extremely tough, sending out underground runners containing bulbs, which can regenerate new plants quickly, covering a large area in one season. The seed can stay dormant for long times until the soil is disturbed and it acts as a pioneer quickly covering the area.

Common problems with Sea-Urchin Grass

Generally problem free

    How to harvest Sea-Urchin Grass

    The best way to eradicate nut-grass is to physically dig it out of the ground or lawn, making sure to follow and remove the root system and bulbs as you go. Continue after every re-emergence where some of the roots or bulbs were left in the ground. Remove again, always trying to remove everything.

    How to propagate Sea-Urchin Grass


    Spread easily by seeds. Seed is said to be dormant in soil up to 70 years!


    The roots will send new suckers all around the area of a mother plant.


    Small bulb-lets remain in the soil when pulling up the grass and will grow into new plants.

    Special features of Sea-Urchin Grass


    Other uses of Sea-Urchin Grass


    The plant is used in traditional Chinese medicine.


    Despite the bitter taste of the tubers, they are edible and have nutritional value, the plant is known to have been eaten in Africa in famine-stricken areas. It is often described for the nutty flavor hence the common name nut-grass or nut-sedge.