Grassleaf sweet flag

Year-round

Grassleaf sweet flag is a low, evergreen, grass-like clump native to East Asia, so it is an introduced plant here rather than a native one. It stays about 6 to 12 inches tall and prefers part shade with consistently moist soil, such as a pond edge or a damp bed.

• Give it part shade and soil that stays moist. It sulks if it dries out.
• Plant it at a pond edge, in a rain garden margin, or in a container that does not dry out.
• Divide crowded clumps in spring to keep the fans of leaves fresh.
• Trim off brown leaf tips to keep it neat.

Its small, evergreen fans stay tidy year round, which suits a front-yard edge or water feature.

Fall

Fall is a gentle time to plant while soil is still warm and rains return.

• Plant or move clumps once temperatures ease.
• Keep soil moist until winter rains arrive.
• Remove debris that settles in the leaf fans.

Winter

Grassleaf sweet flag stays evergreen through mild winters, so little work is needed.

• Leave the foliage in place.
• Water if a dry spell lasts more than a couple of weeks.
• Hold off on dividing until spring.

Spring

Spring is the best time to plant or divide grassleaf sweet flag as growth restarts.

• Divide and replant clumps now.
• Keep new plantings evenly moist.
• Clip any winter-worn leaf tips.

Summer

Dry summer weather is the main stress for this moisture-loving plant.

• Water often enough that the soil never fully dries.
• Give afternoon shade where you can.
• Mulch to hold moisture around the clump.