In the spring, the cascading leaves of hakone grass are bright yellow before darkening to gold and red in the fall. These ornamental characteristics helped it win the 2009 Perennial Plant of the Year award from the Perennial Plant Association. It is commonly grown in USDA hardiness zones 5 through 9 and can reach a height of up to 18 inches. Though you can often buy hakone grass seed in nurseries, save yourself money by collecting the seeds from an established grass plant.
Inspect the hakone grass plant for flower stalks. The stalks begin to appear at the end of summer and are pale yellow or green in appearance, usually forming in the center of a hakone grass bunch.
Wait for the flower stalk to produce small seeds. Before the seeds mature, slide a paper bag over the flower stalk head and use a rubber band to tie off the bottom of the bag around the stalk's stem. The seed head is now contained inside the bag.
Let the stalk dry on the hakone grass plant. Once the stem is dry and brittle, break it off from the plant.
Shake the bag vigorously while keeping it shut. The seeds on the seed head will dislodge inside the bag. Remove the actual stalk and store the paper bag in a cool, dry environment until you're ready to plant the grass seeds.