Once they get into the garden, montbretia, Crocosmia X crocosmiiflora, may never leave. They sometimes survive the demolition of their original garden to emerge and bloom in the garden of a new home built on the same site. Bulbs (actually corms) multiply surprisingly efficiently to form large colonies that should eventually be divided if they get too crowded to bloom. Ungroomed plants sow seeds that may be invasive.
The one or two inch wide flowers are almost always bright orange, but can sometimes be reddish orange, yellow or pale yellow. The branched flower stems are two or three feet tall or a bit taller, and stand nicely above the grassy foliage. The narrow leaves are about half and inch to an inch wide.