Quick comparison
Miscanthus (maiden grass, Japanese silver grass) and Pennisetum (fountain grass) are both warm-season ornamental grasses that flower in late summer. They are often confused, but they suit different jobs.
| Miscanthus | Pennisetum | |
|---|---|---|
| Common names | Maiden grass, silver grass | Fountain grass |
| Typical height | Roughly 3 to 8 feet or more | Roughly 1 to 5 feet |
| Shape | Upright, arching or vase-shaped | Mounding, cascading “fountain” |
| Flowers | Feathery plumes that turn silvery | Bottlebrush or foxtail-like plumes |
| Typical hardiness | Often zones 4 or 5 to 9 | Often zones 5 to 9, with some tender types |
| Best for | Screens, backdrops, tall accents | Borders, paths, containers |
Heights and hardiness vary by species and cultivar, so check the tag.
Size and shape
Miscanthus sinensis is the larger plant. Many cultivars reach 5 feet or more, and a few get much taller, with some compact selections such as ‘Adagio’ staying smaller. The leaves are long and narrow and the clump is upright or arching, which makes it useful as a screen or a vertical backdrop.
Pennisetum is generally smaller. Fountain grass forms a rounded mound of arching leaves, usually in the range of 1 to 5 feet depending on the type, which suits the front or middle of a border. Dwarf cultivars such as ‘Hameln’ stay around 3 feet in many descriptions.
Flowers and plumes
Miscanthus plumes appear in late summer or fall and are fine-textured and feathery. They often fade to silver and can stand well into winter.
Pennisetum flowers look like bottlebrushes or fox tails, in cream, pink, burgundy and even near-black. They often appear earlier, from midsummer, and many types turn gold in fall.
Hardiness and tender types
Both groups include hardy and tender plants. Hardy Miscanthus sinensis cultivars are commonly sold for zones 4 or 5 to 9. Hardy fountain grass (Pennisetum alopecuroides) is usually sold for zones 5 or 6 to 9. Purple fountain grass (Pennisetum setaceum ‘Rubrum’) is a tender type that many gardeners in cold climates treat as an annual or overwinter indoors.
Care differences
Both want full sun (at least 6 hours) and well-drained soil. The details differ slightly:
- Miscanthus generally appreciates a bit more moisture, and it is the one tall grass that can benefit from some extra fertilizer, although too much can make it flop.
- Pennisetum prefers average moisture and can show brown leaf tips if it dries out. It is also sensitive to deep planting, so keep the crown level with the soil surface.
- Both are cut back in late winter or early spring, close to the ground. See should all ornamental grasses be cut back in the spring and how to care for ornamental grasses.
Spreading and invasiveness
Both genera need a little caution, and the details depend on where you live.
- Some Miscanthus sinensis plants self-seed, and the species is listed as invasive in some areas of the eastern United States. Sterile or low-seeding cultivars are available. Some taller types, such as Miscanthus sacchariflorus, spread by rhizomes.
- Some fountain grasses drop seed freely, and Pennisetum setaceum is considered invasive in several warm regions. Sterile cultivars are the safer choice.
Check your local invasive plant list before planting, and see our guide to non-invasive ornamental grasses for alternatives.
Popular cultivars
- Miscanthus: ‘Gracillimus’ (narrow, arching leaves, 5 to 7 feet in some descriptions), ‘Morning Light’ (white-edged, compact), ‘Adagio’ (compact), ‘Silberfeder’ (tall, silvery plumes), ‘Zebrinus’ (horizontal gold bands).
- Pennisetum: ‘Hameln’ (dwarf with cream plumes), ‘Little Bunny’ (very small), ‘Burgundy Bunny’, ‘Cassian’s Choice’ (taller, with orange fall color).
Which should you choose?
- Choose Miscanthus if you want a tall screen, a backdrop or a big focal point, and you have room for it.
- Choose Pennisetum if you want a softer, smaller mound for a border, path edge or container.
- If neither seems right for your site, other warm-season clumpers such as switchgrass, little bluestem or muhly grass are worth a look. See warm-season vs cool-season ornamental grasses and the wider overview of types of ornamental grasses.