Bulrushes are common aquatic plants found at the edges of bogs and marshes and in the margins of rivers and ponds. There are several species and they are widely found across North America. The bulrush is a perennial that grows in thickets along or in waterways. The tallest species grows 10 feet tall and spreads from a dense rhizome. The plants produce a tuft of a flower that is rather twiggy and unremarkable. Seeds ripen in late August into September and germinate readily in moist, fertile soil. Bulrush is an important plant for wildlife and fowl and is a subject for re-establishment in natural areas.
Harvest seed at the end of summer. Hold a bag under the seed heads and lop them off with garden shears. Bring them indoors and spread them out on a counter to dry completely for at least 24 hours. Put the seed heads in a mortar and pestle to crush them.
Pour the crushed seed heads and chaff onto a fine mesh screen. Either take the screen outside and gently toss the contents up and down in a breeze or hold the screen in front of a fan and allow the air to catch the lightweight chaff and blow it off the seeds.
Dampen a large piece of sphagnum moss and enfold the seeds inside. Put the moss in a zip-top bag into the refrigerator. Let the seeds chill for at least 30 days and up to 75 days. Keep the sphagnum moss damp during this time.
Mix half potting soil and half compost and put it in the seed tray. Thoroughly moisten the soil/compost mix. Press the seeds into the surface of the medium at a distance of 1 inch from each other. Place a lid on the tray and put it on a seed-warming mat set to 21.1 to 23.9 degrees Celsius. Germination will occur in one week to ten days.
Transplant the plants when they are 5 inches high. Put them in an area with moist, rich soil in standing water no deeper than 1 inch. Plant them 12 to 18 inches apart for a close stand when the bulrush seedlings are full grown. Water levels can increase as the plants get taller.