American Sweet Flag

American Sweet Flag is a perennial wetland plant native to North America, often found along the edges of streams, ponds, and marshes. It grows 2 to 4 feet tall in elegant, fan-like clumps of upright, sword-shaped green leaves. When crushed, the foliage releases a sweet, citrus-like fragrance. Unlike many grass-like plants, Sweet Flag spreads slowly via rhizomes and has a distinctively ridged leaf midrib.

This species thrives in wet to consistently moist soils and is excellent for rain gardens, pond edges, and wetland restorations. It’s also valuable for its soil-stabilizing root system and ecological contributions, offering shelter for small aquatic creatures and attracting pollinators when in bloom.

Care should be taken to ensure that the native species, A. americanus and not the globally distributed but exotic A. calamus is cultivated. Both species look quite similar.

• Prefers saturated soils; plant in wet conditions or shallow standing water for best results.
• Remove dead or tattered foliage in early spring to tidy up the plant.
• Thrives in rich, mucky, or loamy soils with steady moisture.
• Mulch is not usually needed in wet conditions but can use a thin mulch layer in rain gardens to suppress weeds if necessary.
• Low-maintenance once established; may slowly spread via rhizomes. Divide every few years in spring if clumps become too dense.