I can’t belive this has never been plant of the day, it is definitely one of my top 400 favorite plants!
Growing to about 18″ x 18″ but spreading into wide clumps with age, this deciduous grass thrives in partial sun and will reward regular waterings with graceful, flowing leaves from late spring through fall. The slender leaves of the cultivar ‘Aureola’ are brightly striped; ‘All Gold’ is a shocking chartruse; ‘Albostriata’ is taller with subtler white stripes; ‘Beni kazi’ is striped and a little spikier looking and has the best fall color: rich pinks, copper and gold.
In summer airy seed heads appear, slightly drooping like the leaves. When the weather turns cold the plants turn straw colored and can be left for winter interest or cut back to the ground. I prefer to leave them over the winter- I think the leaves help protect the crown while providing shelter for overwintering insects. Either way, remove old foliage before new growth begins in spring. When the clumps become large, they can be divided every 2-3 years in spring.
Japanese Forest grass looks gorgeous in masses in a woodland garden, under Japanese or vine maples, or near water features or ponds. It likes moist, well-drained soil but is pretty adaptable, so it can give a lush, watery look even when there isn’t actually abundant water, such as next to a dry creek bed or a self-contained fountain.
It’s hardy in zones 5 to 9, or with some protection in zone 4. I had ok luck with it there- it survived but was really slow growing. It’s reportedly deer resistant.