What Makes Nassella So Special?

Nassella grasses are prized for their incredibly fine texture and graceful, airy movement in the slightest breeze. They create a soft, almost ethereal effect in the landscape, especially when planted in masses. Their delicate inflorescences (flower plumes) catch the light beautifully, adding a shimmering quality. It is this combination of fine texture, movement, and light-catching ability that sets them apart from many other ornamental grasses. They bring a sense of wildness and natural beauty to the garden.

Description

• Growth Habit: Clump-forming, perennial grasses. They form dense, tufted clumps.
• Height: Varies depending on the species but generally ranges from 1 to 3 feet tall (and sometimes wider).
• Foliage: Extremely fine, thread-like leaves (blades). The color is usually green or blue-green.
• Flowers: Delicate, airy panicles (branched flower clusters) that rise above the foliage. The individual flowers (spikelets) are small and often have long, needle-like awns (bristles), giving them their common name. The plumes can be silvery, tan, or purplish.

Details Gardeners Care About

• Sunlight: Full sun is best for optimal growth and flowering. They can tolerate a little bit of light shade, but flowering will be reduced.
• Soil: Well-drained soil is essential. They tolerate a wide range of soil types, including poor, dry, sandy, or rocky soils. They do not like wet, soggy soil.
• Water: Drought-tolerant once established. Water regularly when young but then reduce watering significantly.
• Hardiness: Varies depending on the species. Many are hardy in USDA zones 7-10, but some are more cold-sensitive.
• Deer Resistance: Generally considered deer-resistant.
• Self-Seeding: Some species, particularly Nassella tenuissima (Mexican Feather Grass), can self-seed readily. This can be a plus or a minus, depending on your preference.

Native Habitat

Nassella species are native to:

• North America (primarily the southwestern United States and Mexico)
• South America

They are often found in:

• Prairies
• Dry grasslands
• Open woodlands
• Rocky slopes

Landscaping Design Tips

• Mass Planting: Plant in groups or drifts for a stunning display of texture and movement.
• Mixed Borders: Use them in mixed borders to add a soft, airy element.
• Rock Gardens: Their drought tolerance and fine texture make them a good choice for rock gardens.
• Meadow Gardens: A natural fit for meadow or prairie-style gardens.
• Dry Gardens: Excellent for xeriscaping (water-wise gardening).
• Containers: Smaller species or cultivars can be grown in containers.
• Erosion Control: The deep roots can help stabilize slopes.
• Contrast: Use them to contrast with plants that have bolder foliage or flowers.

Planting and Care

• Planting Time: Spring or fall.
• Spacing: Space plants 1-2 feet apart, depending on the species and desired effect.
• Planting Depth: Plant at the same depth they were growing in their nursery pots.
• Watering: Water thoroughly after planting and keep the soil moderately moist until established. Then, reduce watering significantly.
• Mulching: Mulch can help retain moisture and suppress weeds, but it is not essential. Avoid burying the crown of the plant.
• Fertilizing: Generally, does not need much fertilizer. A light application of compost or a slow-release fertilizer in spring can be beneficial.
• Pruning: Cut back the foliage to the ground in late winter or early spring before new growth emerges. This is important for maintaining a tidy appearance and encouraging vigorous growth.
• Division: Divide clumps every few years in spring or fall to rejuvenate the plants and propagate new ones.
• Controlling Self Seeding: Deadhead to prevent self-seeding if this is not desired.

Taxonomy (Simplified)

• Genus: Nassella (formerly often included in the genus Stipa)
• Family: Poaceae (Grass family)
• Common Species (Examples):
• Nassella tenuissima (Mexican Feather Grass, formerly Stipa tenuissima) - The most popular species, known for its incredibly fine texture and prolific self-seeding.
• Nassella pulchra (Purple Needlegrass) - California's state grass.
• Nassella cernua (Nodding Needlegrass)

Morphology (Simplified)

• Stems: Erect, slender stems (culms).
• Leaves: Very narrow, thread-like, often rolled inwards.
• Flowers: The inflorescence is a panicle (a branched cluster of flowers). The individual flowers (spikelets) are small and often have long, needle-like awns.
• Roots: Fibrous root system, often quite deep.

Other Insights

• Movement: The slightest breeze will set Nassella grasses in motion, creating a beautiful, dynamic effect in the garden.
• Drought Tolerance: Once established, they are exceptionally drought-tolerant, making them a good choice for water-wise gardens.
• Self-Seeding (Caution): Nassella tenuissima, in particular, can be a prolific self-seeder. In some regions, it has become invasive. Be aware of this potential and plant responsibly. Consider using other Nassella species if this is a concern.
• Texture: The incredibly fine texture is a key characteristic. It contrasts beautifully with plants that have coarser foliage.
• Sharp Awns: The "needle" of the needlegrass is quite sharp.

In conclusion, Nassella grasses are a fantastic choice for adding texture, movement, and a touch of wildness to the garden. Their drought tolerance and adaptability make them valuable plants for a variety of situations. Just be mindful of the self-seeding potential of some species, especially Nassella tenuissima, and choose the appropriate species for your region and gardening style. The graceful, airy beauty they provide is well worth it.