Invasive species

Invasive purple loosestrife

Purple loosestrife (Lythrum salicaria) is a perennial that blooms in midsummer. The upright bushy plants can reach 7′ tall and features pink to purple flowers traveling up a long spike. It grows quickly and crowds out marsh vegetation needed by wildlife for food and shelter. The plant is native to Asia and Europe but has become an established aquatic invasive in the U.S.; you can see it along wetlands, stream banks and by shallow ponds.

In Oregon, specialists have used four biological controls for purple loosestrife with some success: two leaf beetles, a root weevil and a seed weevil.


Some native plant alternatives are:

  1. Douglas spirea
  2. Meadow checkermallow
  3. Common camas
  4. Small-flowered bulrush
  5. River lupine



Sauvie Island Pond Project

In 2012, District staff and then-board chair Jane Hartline (an enthusiastic volunteer) identified nine different landowners with potential to improve wildlife habitat at their 10 Sauvie Island ponds, which total 6.5 acres. The project began […]