1. Purple Loosestrife Lewis Pell
‘Weeds of North America’ –Richard Dickinson & France Royer
-2014
 Has rapid spreading and reproduction.
 Seeds are viable in soil for up to 20 years.
o Germination occurs at 20°C (68°F), no germination <14°C (57.2°F).
o Large plants can produce up to 2.7 million seeds in 900-1,000 capsules.
o Top 2cm of soil may trigger emergence of seedlings.
 Plants can live up to 22 years.
 Seeds, root fragments, and/or stem may cause reproduction.
 Replacing native vegetation in wetlands.
 Host for cucumber mosaic virus.
 Slows down water flow.
 Native species Swamp Loosestrife similarly mistaken for Purple Loosestrife. (Look
up for difference in identification)
 Hairy Willow Herb is commonly associated with Purple Loosestrife. If found together
it’s important to manage removal of both: eventually outcompetes Purple Loosestrife.
JStor
-A stem cut and blade delivery method of herbicide application for weed control-
Richard L. Wahlers, James D. Burton, & Eleanor P. Maness (1997)
Shear blades placed in diluted water concentrations (0,5,10,20,50, & 100%) with either
Clopyralid or Triclopyr, final volumes either 1 or 5 microliters.
5% T, reduced regrowth by 28% -260 days after treatment
10%T, reduced regrowth by 75% -260 DAT
20%T, reduced regrowth by 88% -260 DAT
-no regrowth of purple loosestrife occurred at 50% and/or 100%
-The Biology and Management of Purple Loosestrife (Lythrum Salicaria)-
Barbra H. Mullin (1998)
Integrated management is works best for a long-term management as well as cost-
efficiency, using:
Chemicals (Glyphosate and/or Triclopyr)
Biological controls (Loosestrife Root Beetle, Golden Loosestrife Beetle, Black Margined
Loosestrife Beetle, Loosestrife Seed Weevil, Blunt Loosestrife Seed Weevil)
Physical forms of management (Hand Removal, Cutting, and Burning)
-Recovery of Native Flora and Behavioral Responses by Galerucella spp. Following
Biocontrol of Purple Loosestrife-
Mathew F. Albright, Willard N. Harman, Scott S. Fickbohm, Holly Meehan, Sarah Groff,
&Tavis Austin (2004)
Decimated purple loosestrife populations first year or two introduced, after that non-
target plants such as the Speckled Alder and the Red Osier were beginning to be affect.
Web of Science

2. -An Integrated Strategy for the Control of Purple Loosestrife in Netley- Libau Marsh,
Southern Manitoba-
D.C. Henne, C.J. Lindgren, T.S. Gabor, H.R. Murkin, & R.E. Roughley (2005)
Chemical: Glyphosate &Triclopyr Amine
Biological: Galerucella Calmariensis
Tested together and separately. Alone the biological control had no significant difference
from the mean stem number, but the herbivore reduced the mean stem height by 70%, but
the mean stem densities increased. Together with an integrated method the results had a
higher output.
Book
-Invasive Plants of Pittsburgh-
Cut and Pull small stands in late spring, careful to bag and remove all plant material. Re-
sprouting may occur from root, monitor for regrowth.
Management:
With the previous findings in my research as well as an applied fieldwork experience I
have a number of suggestions on how to manage the Purple Loosestrife.
1-3, from most-disturbance too least-disturbance on the land.
Be sure to cut flowers, if plant is flowering, and bag them before proceeding with any of
the following management options.
-This will lower the chances of new seeds from dropping or being produced.
1.
a. Use the pulling method: this will extract most of the plant if done
properly. It is likely that root fragments will be left behind.
b. Using a spray bottle with 25-35% Triclopyr, spray region where plant was
previously extracted.
2.
a. Using shears that will not damage the vascular system of the plant cut the
stem close to the ground also cutting the root system.
b. Using a spray bottle of 25-35% Triclopyr, spray the remainder of the stem
as well as the exposed root fragments.
3.
a. Using shears that will not damage the vascular system of the plant cut the
stem close to the ground.
b. Using a spray bottle of 25-35% Triclopyr, spray the remainder of the stem
During management be sure to bag all “dead”/undesired plant material. The plant is
capable if re-growing by root fragments, stem, or seed.
If absolutely no re-growth is desired it’s better to use 50-100% Triclopyr if capable.