How to Grow Giant Reed
Wikimedia Commons
Giant Reed
Arundo donax
grassArundo donax, commonly called giant reed, is a tall perennial grass that can grow 15-20 feet high with thick, woody stems and broad, blade-like leaves. Native to the Mediterranean region, it spreads rapidly through both seeds and underground rhizomes, making it highly invasive in many regions. Despite its invasive nature, it has been studied for biomass production and biofuel potential.
When should you plant Giant Reed in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Giant Reed timeline · Pittsburgh, PA (Zone 6b)
-
Plant Giant Reed
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
Harvest Giant Reed
Around Apr 18≈ 1 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Giant Reed dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 6-11; highly invasive in warm climates
Sign up free to see if Giant Reed grows in your zone — and get a personalized planting timeline.
Get my Giant Reed timeline →Growth Stages
Establishment
2-4 weeksYoung shoots emerge from rhizomes in spring with small, tender stems and developing leaf blades
Ensure consistent moisture during first few weeks; protect from foot traffic
Rapid Growth
8-12 weeksShoots elongate rapidly, reaching 6-10+ feet tall with multiple stems per rhizome node and increasingly dense foliage
Monitor spread closely; cut back if containment is needed; support tall stems if in windy areas
Maturation
4-8 weeksStems reach full height (15-20 feet), become woody and rigid, with thick, woody internodes and full canopy development
Remove dead leaves; note that mature stems can shade understory plants significantly
Flowering
4-6 weeksPlumes form at stem tips in late summer/fall, with large silvery-white or tan panicles (8-20 inches long)
Seed production contributes to spread; cut flower panicles before seed maturation if controlling population
Dormancy
3-4 monthsAbove-ground stems die back in winter in cold climates; rhizomes remain alive underground ready to re-sprout in spring
Cut dead stems to ground level in late fall/early winter; remove debris to reduce fire hazard
Companion Planting
Plan your garden →Avoid planting near:
Common Pests
-
Generally minimal pest pressure; manages as a landscape plant
-
Spray with water; use insecticidal soap if severe (rarely needed)
-
Monitor for infestations; horticultural oil or neem oil if necessary
Uses
Biomass & Biofuel Production
HouseholdGiant reed is being researched extensively as a dedicated energy crop due to its rapid growth, high yielding biomass, and ability to grow on marginal lands. The woody stems can be processed into biofuel, ethanol, or combustible material. [source]
Ornamental Panicles & Decorative Displays
CraftThe large, silvery flowering panicles are attractive in dried flower arrangements and can be used for interior decoration or craft projects. The tall, architectural form provides visual interest in large landscape settings. [source]
Erosion Control & Phytoremediation
HouseholdDespite invasive tendencies, giant reed can stabilize streambanks and slopes, and research suggests it accumulates certain contaminants from soil and water, potentially useful for bioremediation of degraded sites. [source]
Traditional Food Use (Limited)
CulinaryIn some Mediterranean and Middle Eastern regions, young shoots are occasionally eaten as a vegetable when tender, similar to asparagus. However, this use is uncommon in modern horticulture. [source]
Habitat Provision (Cautionary)
WildlifeWhile it can provide dense cover for some wildlife, its invasive spread typically displaces native vegetation and reduces overall biodiversity in natural ecosystems. Use with extreme caution in ecologically sensitive areas. [source]
Harvest Tips
Cut stems for biomass in late summer/early fall after flowering but before seeds fully mature. Use sharp tools to cut at ground level. For ornamental panicles, harvest when plumes are fully developed and silvery. For biofuel/pulp applications, timing is critical—harvest at peak dry matter content (typically fall).
Fun Facts
- 🌱 Giant reed is one of the most invasive plant species in the world, capable of forming monocultures that exclude all other vegetation and dominate river systems across six continents.
- 🌱 A single plant can produce millions of seeds per year, and even small rhizome fragments (as small as a pencil eraser) can regenerate into full plants, making eradication extremely difficult.
- 🌱 The plant has been used for centuries in traditional Mediterranean cultures—ancient Greeks and Romans used it for reeds in wind instruments, fishing rods, and building materials.
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Giant Reed planting timeline
Tell us your zip code and we'll calculate exactly when to start Giant Reed seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Giant Reed timeline →