how fast does pampas grass grow
Pampas grass (Cortaderia selloana) is a fast‑growing ornamental grass that can put on several feet in a single growing season under good conditions.
Growth speed in numbers
- Per month: In favorable climates, pampas grass often grows about 6 inches (15 cm) per month , with peaks near 12 inches (30 cm) per month in peak‑growth conditions (warm, sunny, moist but well‑drained soil).
- Per year: Many sources report it can reach 6–10 feet (1.8–3 m) tall within one season, in some cases adding 2–3 feet (60–90 cm) or more in height per year after establishment.
- Per day: Under ideal summer conditions with plenty of water and sun, one specialist grower notes it can look as if it’s growing up to about 1 inch (2.5 cm) per day at its fastest spurt.
Time from planting to full size
- Seeds to maturity: Germination itself can take about 2–4 weeks , after which growth accelerates; the plant usually reaches full size and starts flowering in 2–3 years , sometimes up to 4 years depending on climate and care.
- Key stages:
- Year 1: Focuses on root and leaf‑clump development; height may be modest but the plant is “filling in.”
* **Years 2–3:** Growth speeds up, stalks rise several feet, and **plumes (feathers) appear** once the plant is well established.
Factors that change how fast it grows
- Sunlight: Full sun (6+ hours direct light) yields the fastest growth; shade slows it and can reduce plume production.
- Soil and water: Moderately fertile, well‑drained soil with consistent moisture in the first year boosts growth; very poor or waterlogged soil can stall it.
- Climate: Warmer zones (roughly USDA 7–11) see the most dramatic “several feet per year” growth; cooler areas may see slower, shorter plants.
Quick‑reference table: how fast pampas grass grows
| Timeframe | Typical growth | Notes |
|---|---|---|
| Per day | Up to about 1 inch (2.5 cm) | During peak‑growth summer with plenty of water and sun. | [3][7]
| Per month | Roughly 6 inches (15 cm), up to 12 inches (30 cm) | Under ideal conditions; usually slower in cooler or drier spots. | [1][5][3]
| Per year | Several feet (often 2–3 ft / 60–90 cm), up to 6–10 ft (1.8–3 m) tall in one season | Highly dependent on climate, soil, and sun exposure. | [5][7][3]
| To maturity (seed) | 2–4 years from seed to full‑size, flowering plant | First year is more “establishment”; showy plumes come later. | [10][6][9]