Botanical Name: Sagina subulata Common Name: Irish Moss Hardiness Zone: Perennial in USDA Zones 4–8 Size: 1–2" Tall × 12–18" Spread Growth Habit: Low-Growing, Dense, Mat-Forming Groundcover Sunlight: Full Sun to Partial Shade Soil: Moist, Well-Drained Soil; Prefers Cool Conditions Water Needs: Moderate; Keep Consistently Moist Bloom Season: Late Spring to Early Summer Fertilizer: Light Feeding in Spring; Avoid Excess Fertility Features: Fine Moss-Like Texture, Tiny White Star-Shaped Flowers, Evergreen Appearance, Soft Carpet Effect Uses: Pathways, Rock Gardens, Stepping Stones, Containers, Edging, Groundcover

Patent: ❌ Not Patented Propagation: ✔ Propagation Permitted

More About Sagina subulata (Irish Moss)

Sagina subulata, commonly known as Irish Moss, forms a lush, emerald-green carpet that resembles soft moss but is actually a hardy flowering perennial. In late spring to early summer, tiny white star-shaped flowers appear just above the foliage, adding subtle seasonal interest.

Unlike true moss, Irish Moss tolerates light foot traffic and thrives in garden settings where a living green carpet is desired. Its fine texture makes it especially attractive between stepping stones and along pathways.

Why We Like It (Our Trials)

In our trials, Irish Moss has proven to be an excellent choice for cool-season groundcover, performing best in areas with afternoon shade and consistently moist, well-drained soil. It maintains its dense, low profile without becoming invasive.

We especially appreciate its polished, finished look. Few groundcovers provide such a clean, manicured appearance at ground level.

Irish Moss vs. Other Groundcovers

Compared to creeping phlox, Irish Moss offers a much lower profile and finer texture, making it ideal where height must be kept to a minimum.

When compared to Blue Star Creeper or Mazus, Irish Moss delivers a denser, more carpet-like appearance, though it prefers cooler conditions and regular moisture. For gardeners seeking a soft, moss-like groundcover with ornamental appeal, Sagina subulata is an excellent choice.