Discover Igusa
Contents
What is Igusa?
The Natural Beauty of Japanese Rush Grass
A Sustainable Japanese Material Connecting Nature and Tradition
Imagine walking into a calm Japanese room. The floor feels smooth, the air smells fresh like a forest after rain.
That soothing scent and feeling come from a natural material called Igusa (Japanese rush grass).
Igusa is a slender, green plant that grows in clean wetlands. After harvesting and drying, it becomes the main material for tatami mats. The traditional flooring used in Japanese homes for over a thousand years.
Why is Igusa special?
| Effect | Benefit for Your Home |
| Humidity Control |
Igusa naturally acts like a sponge. It has an incredible ability to absorb excess moisture from the air, which is highly effective for reducing that sticky, humid feeling you get when it rains. Conversely, it releases moisture when the air is dry, helping to keep the room consistently comfortable and discouraging mold growth. |
| Air Purification Power |
The rush fibers have a sponge-like structure that actively absorbs harmful chemicals from the air, such as nitrogen dioxide and formaldehyde (a substance often found in new furniture and building materials). |
| Deodorizing Effect |
Igusa is highly effective at neutralizing unpleasant odors, including the smell of sweat, pet odors, and tobacco smoke. The woven mat surface traps and breaks down these odors. |
| "Forest Bathing" Effect |
The unique, fresh scent of Igusa contains components like Phytoncide and Vanillin. These are the same chemicals found in a forest, and research shows they have a profound calming effect, promoting relaxation, reducing stress, and even improving sleep efficiency. |
| Stain Resistance |
The surface of Igusa fibers naturally contains a layer of wax. This wax helps to repel liquids and stains, making it easier to wipe up spills before they soak into the mat. |
| Fire Resistance | Unlike many synthetic materials, the tightly woven, natural Igusa material possesses fire-retardant properties (it is non-flammable). It is difficult for it to catch fire, and even if it does, it tends to smolder rather than quickly burst into flames, making it a safer material for the home. |
Modern Uses
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In Japan, Igusa has been loved for centuries as the heart of tatami culture.
Today, this natural material is reimagined in modern forms like rugs, cushions, slippers, yoga mats, and even bags. Blending traditional craftsmanship with contemporary lifestyle.Through these products, IKEHIKO brings the timeless comfort, calming aroma, and eco-friendly beauty of Japanese Igusa to homes around the world.
The Cultivation Story
The Artisan's Touch: A Two-Year Commitment to Quality
The exceptional quality of our Igusa comes from a meticulous, eight-step cultivation process carried out over two full years by dedicated Japanese farmers.
Crucially, Igusa does not grow from seed. It must be raised from established seedlings, emphasizing the hands-on care required. This is not mass production. It is an art form.
1.Raising Seedlings & Dividing Stems
Starts 2 years prior (May)
Igusa seedlings are first grown in fields with good soil during the summer. In the autumn, the grown plants are dug up, and the larger stalks are carefully separated (kabuwake). This is done to adjust the thickness of the seedlings, ensuring they are suitable for planting. This precise division requires the skilled hands of master craftsmen.
2. Planting
Late November – Early December
As winter arrives, the seedlings are planted in flooded paddy fields, similar to rice farming. The young Igusa stalks are evenly spaced across the field.
3. Tip Trimming (Sakigari)
Late April – Early May (65–70 days before harvest)
In spring, Igusa (Japanese rush) grows rapidly. From a single seedling, new shoots sprout around it. Japanese farmers affectionately call these “child” and “grandchild” shoots, as they grow from the parent stalk like a family.
If the main stalk grows too tall, it can block sunlight from reaching the smaller shoots below. To ensure even growth, farmers carefully trim the tips of the taller stalks a process called “Tip Trimming” (Sakigari).
This allows sunlight to reach every part of the field, helping the Igusa grow strong, balanced, and healthy.
4. Netting (Amikake)
Mid – Late May
After the Tip trimming, nets are carefully placed over the Igusa. As the grass grows to waist height during the rainy season, the nets prevent the tall stalks from being bent or broken by strong winds or rain. The height of the net is raised as the rush grass grows.
5. Harvesting (Karitori)
Late June – Mid July
Summer is harvesting time! The nets are removed, and the Igusa, which has reached a peak height of 160–170 cm (approx. 5.2–5.6 feet), is cut using a special machine. To prevent the Igusa from being damaged by the summer heat, harvesting often starts in the early morning hours, with water sometimes sprayed onto the stalks during the process. The harvested stalks are bundled for the next stage.
6. Mud Dyeing (Doro-zome)
Immediately post-harvest
Mud dyeing (Dorozome) is a natural finishing method used for high-quality Igusa.
After harvesting, the rush is soaked in iron-rich river mud, then dried under the sun. This method developed in the Kyushu region of Japan, especially in Kumamoto, where the best Igusa is grown.
This simple, chemical-free process turns the green stalks into a deep, earthy brown, giving Igusa a soft shine and strength.
Why It’s Special
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Eco-Friendly – Uses only water, mud, and sunlight 【no artificial dyes】
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Durable & Long-Lasting – The iron minerals strengthen fibers and prevent fading.
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Unique Color – Each piece develops its own tone that deepens beautifully over time.
7. Drying & Sorting
After mud dyeing, the Igusa stalks are thoroughly dried using a special drying machine.
Once completely dry, they are carefully sorted by length in precise 2-sun (about 6 cm) increments.
Longer Igusa stalks are stronger and more valuable, so this step is crucial in determining which stalks will be used for each product.
Covered in fine clay, skilled craftsmen sort each bundle by hand with great care and attention to detail.
8. Storage
The sorted Igusa is stored in black bags to protect it from sunlight and prevent discoloration (sunburn). These raw materials are then delivered to weaving and dyeing artisans, who transform them into the final products like Tatami mats.
This dedication, from the initial planting to the final preparation, is why genuine Igusa products offer such high quality, durability, and a wonderful scent. The work of young farmers in Yatsushiro City, Kumamoto Prefecture (Japan's main Igusa production area), ensures this tradition continues.
Craftsmanship Process
1.Dyeing – The Coloring Process
①Selection
Each morning begins with checking and sorting the Igusa delivered the day before.
The craftsman carefully separates them by type, size, and age. Small differences affect how the grass absorbs dye.
“Older Igusa absorbs differently from new ones.
Experience tells us how to adjust,”
②Preparation
The Igusa is divided into precise bundles according to the color plan.
Every batch must be balanced in weight and moisture content before entering the dyeing machine.
③Machine Dyeing
All Igusa are dyed using large dyeing machines.
Inside, the temperature reaches around 60°C, filling the room with steam.
Each batch’s weight increases from 3 kg to 9 kg after absorbing the dye. A physically demanding process for the craftsman.
④Drying
After dyeing, the colored Igusa is dried carefully to preserve the hue and natural texture.
Temperature and humidity are constantly adjusted to prevent uneven color or deformation.
⑤Finishing & Inspection
Once dry, every bundle is checked by eye.
Only evenly dyed, high-quality Igusa are selected for weaving.
This stage determines how beautiful the final woven patterns will appear.
Weaving – From Dyed Igusa to Beautiful Mats
1. Design Card Setup & Preparation
The artisan sets up the design card and prepares the loom according to the desired pattern.
This ensures every weave matches the intended design perfectly.
2. Softening the Igusa【kashitsuke】
Dried Igusa is soaked in water to make it flexible and ready for weaving.
This process, called 【kashitsuke】, softens the fibers while maintaining their strength.
3. Moisture Tuning (kashi-tori)
After soaking the Igusa (kashitsuke), excess water is carefully removed in a process called kashi-tori.
This ensures the fibers are at the right moisture level for smooth and even weaving.
After that, the Igusa is carefully trimmed to remove any unwanted rough parts, ensuring smooth, even strands.
4. Setting Up for Weaving
The beauty of the weave begins with careful preparation.
Before arranging the Igusa on the weaving machine, each strand is carefully inspected and organized by skilled craftsmen. Damaged pieces are removed, and the remaining Igusa is sorted by length and color.
The order and placement of the colors greatly influence the final pattern and overall impression of the product. Through the craftsman’s keen eyes and delicate hands, the foundation for beautiful, balanced designs is created.
5. Weaving
The dyed and softened Igusa is woven into mats following the design.
Skilled hands work meticulously to maintain tension, alignment, and uniformity, creating the final intricate patterns.
6. Finishing & Inspection
Each mat is trimmed, brushed, and thoroughly inspected.
Only pieces that meet strict quality standards move forward as finished products, ready to bring natural beauty and comfort to homes.
After Weaving
1.Resin Coating
A thin layer of resin is applied to the surface to enhance durability, maintain shape, and protect the mat from moisture and wear.
It also prevents color fading or transfer, helping preserve its natural beauty over time.
2.Backing Attachment
Depending on the product, a backing material is attached to the underside like Compressed Polyester padding, PVC, TPE, or Urethane (PU) to add slip resistance, cushioning, and structure.
More about different Backing
3.Edging (Heri)
Finally, a decorative edge cloth (heri) is sewn around the mat.
This not only reinforces the mat but also adds a traditional Japanese finishing touch.
