The best way to kill the purple loosestrife plant is to pull up the roots. I have found that impossible in many cases, and if a piece breaks off, it may sprout. So here is a method that will kill the plant in 2 or 3 years. I have used this method successfully around Mirror Lake
How to Kill
- If you can pull the root, remove it from the ground, let it dry, and die. Then, put it in the garbage. Garbage pits usually don’t have enough water for purple loosestrife to survive, and it should have died in the drying-out period, three to four days.
- If you can’t pull the root from the soil, break it off at the ground level. Then, cut off the top and leave the stem there. The part with the flower is where the seeds are stored. Put those tops in a black plastic bag and leave for a week. When you think they are dead, put them in your garbage. The plant will probably come up next year, and you will remove them again. Without being able to gather solar energy for a season or two, they will run out of a source of energy and die.
How to Identify:
- A skinny purple but tall flower bloom.
- The stem has ridges, usually four, but we have seen purple loosestrife with five ridges.
- They usually like to be near water, sometimes with their root system under water.
- Two leaves are positioned opposite each other on the stem. Each leaf level rotates 90 degrees from the lower or upper leaf level.