Purple loosestrifeis a
woody half shrub, wetland perennial, considered regionally noxious under the BC Weed Control Act.
Purple loosestrife is found
in wet areas at low to mid elevations, growing in ditches, irrigation canals,
marshes, stream and lake shorelines and shallow ponds. It is common in the Lower
Fraser Valley and frequent on Vancouver Island.
Shrub like in appearance, purple loosestrife has stiff, four sided stems ending
in dense spikes of showy purple flowers. Plants have narrow stalkless
leaves, growing up to 3 m in height at maturity.
The best way to identify purple loosestrife
is by its square stems and opposite leaves, just roll the stem in your fingers
to feel the what I mean by
you have purple loosestrife in your garden, remove it immediately. Pull or dig
the plants out and ensure that all root fragments are removed to prevent
For large patches, there are relatively
effective bio control agents like the Galerucella and calmariensis beetles,
both are also called loosestrife beetles and the pusilla beetle, also called
the birch leaf miner beetle. These
beetles feed on the plant stems in their larval stage and can help get a problem
Often confused with fireweed, purple loosestrife is an escaped ornamental that
tolerates a wide range of weather conditions and can grow in standing water.
Seeds distribute through water, humans and
animals, with a single plant producing over 2.5 million seeds that drop in early
fall when temperatures cool.
Boaters are one of the main ways for these
plants to move around, one tiny piece of plant stem can start a new colony, so
when moving a boat from one water coarse to another, you should be sure to
remove any debris on the boat bottom or motor to insure you do not transport and
start a new growth.
Dense stands of purple loosestrife threaten
plant and animal diversity in wetland ecosystems