Grasses to avoid
Some ornamental grasses are naturally aggressive and are best confined to containers or areas where they can be controlled by barriers.
European beach grass (Ammophila arenaria)
Used for erosion control on sand dunes, it has proved invasive on the West Coast but is better behaved in Atlantic Canada. Zone 5
Manna grass (Glyceria maxima)
Spreads aggressively by rhizomes and is difficult to eradicate. ‘Variegata’ is slightly less rambunctious. Zone 5
Blue lyme grass (Leymus arenarius)
Stout rhizomes make it almost impossible to eliminate once well established. Zone 4
Silver banner grass (Miscanthus sacchariflorus)
The black sheep of the Miscanthus tribe, this variety can colonize huge areas in a very short period of time; stick to named cultivars of M. sinensis. Zone 5
Switch grass (Panicum virgatum)
Manageable in regions with moderate soil fertility and low rainfall; avoid planting in rich soil where it can run rampant. Named cultivars tend to be less aggressive. Zone 4, with winter protection
Reed canary grass (Phalaris arundinacea) If provided fertile soil and sufficient moisture, all forms are invasive. Though widely planted, ribbon grass (P. a. var. picta) is no less rambunctious.
Prairie cord grass (Spartina pectinata)
Spreads rapidly in moist soil but is better behaved in poorer, dry soil. Zone 4