How to Grow Tall Ornamental Grasses
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Tall Ornamental Grasses
Various species (Miscanthus, Panicum, Saccharum, Arundo, Phragmites)
grassTall ornamental grasses are decorative perennial or annual grasses that typically reach 4-12 feet in height, valued for their graceful foliage, striking seed heads, and architectural presence in landscapes. They provide year-round visual interest, movement in the wind, and habitat for wildlife. Common tall varieties include Miscanthus × giganteus, Panicum virgatum (switchgrass), and various reed species.
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Example Tall Ornamental Grasses timeline · Pittsburgh, PA (Zone 6b)
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Plant Tall Ornamental Grasses
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Tall Ornamental Grasses
Late summer into fallBefore the first fall frost (≈ Nov 8)
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Growing Conditions
Soil
Growing Zones
Find your zone →Most tall ornamental grasses thrive in zones 5-10, though hardiness varies by species; some cold-hardy types succeed in zones 3-4
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Get my Tall Ornamental Grasses timeline →Growth Stages
Dormancy/Spring Emergence
March-May depending on zonePlant is dormant underground; new shoots emerge in spring as soil warms
Cut back previous year's growth to 4-6 inches in late winter/early spring before new growth appears. Avoid cutting too early in cold climates or too late when new growth emerges. Apply pre-emergent herbicide if weeds are a concern
Vegetative Growth
May-JulyRapid leaf and stem elongation; plant develops full clump with dense foliage reaching 50-80% of mature height
Water regularly if rainfall is below 1 inch per week. Fertilize lightly in spring with balanced fertilizer (10-10-10); avoid excessive nitrogen which promotes weak growth. Thin overcrowded clumps by removing weak shoots. Provide support staking for very tall varieties in windy sites
Flowering/Seed Head Development
August-OctoberFlower panicles emerge from stem tips; plumes develop color (often purple, bronze, or silver) and mature into ornamental seed heads
Enjoy the ornamental display; minimal care needed. Do not deadhead if you want seed development. Continue moderate watering. Some varieties self-seed; deadhead if self-seeding is unwanted
Dormancy/Decline
November-FebruaryFoliage and seed heads turn golden, tan, or bronze; leaves dry and become papery. Plant naturally senesces and looks attractive through winter
Leave standing for winter interest and wildlife habitat; provides shelter for overwintering insects. Do not cut back until late winter (February-March). Avoid trampling dormant clumps which can break emerging spring shoots
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick on small plantings. Use neem oil spray or Bacillus thuringiensis (Bt) for heavy infestations. Most damage is cosmetic on established plants
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Maintain plant vigor with proper watering. Treat with insecticidal soap or neem oil if damage is severe. Rarely causes serious damage to ornamental grasses
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Increase humidity by misting. Spray with water to dislodge. Use miticide or insecticidal soap for heavy infestations
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Prune out heavily infested stems. Apply horticultural oil spray during dormant season. Most infestations are minor
Uses
Dried Arrangements and Decoration
HouseholdTall ornamental grass seed heads are prized for dried floral arrangements, wreath-making, and decorative displays. The plumes dry naturally on the plant and can be cut and brought indoors to last for months. [source]
Wildlife Habitat and Food
WildlifeStanding grasses provide winter shelter for beneficial insects, birds, and small mammals. Seeds feed birds and wildlife through winter months. The structure offers nesting material and protection from predators. [source]
Erosion Control and Soil Stabilization
HouseholdThe deep, fibrous root systems of tall grasses stabilize soil, prevent erosion on slopes, and improve soil structure. They are excellent for rain gardens and bioswale applications. [source]
Biofuel and Biomass Production
CulinaryVarieties like Miscanthus × giganteus are cultivated commercially as a sustainable biofuel source due to rapid growth, high biomass yield, and minimal input requirements. [source]
Crafting Material and Basket Weaving
CraftDried grass stems are used in traditional basketry, thatching, and craft projects. The long, flexible stems can be woven into decorative and functional items. [source]
Harvest Tips
Ornamental grasses are not harvested for food. For decorative use: cut seed heads after they mature and dry in late fall for dried arrangements. Cut foliage in late winter (February-March) before new growth emerges, using pruners or hedge trimmer to cut back to 4-6 inches above ground. Wear gloves as dried foliage can be sharp
Fun Facts
- 🌱 Tall ornamental grasses can grow 3-4 feet in a single growing season, making them among the fastest-growing non-woody plants available for landscaping
- 🌱 Some tall grasses like Miscanthus × giganteus are sterile hybrids that cannot produce viable seed, making them non-invasive while still providing ornamental beauty
- 🌱 In winter, dormant ornamental grass stands provide crucial shelter for overwintering lady beetles, lacewings, and other beneficial insects that control garden pests in spring
Gardening Terms
New to gardening? Learn about terms used in this guide:
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