Purple loosestrife: Is a beautiful purple flower often used in summer bouquets. But they can overtake an area easily, crowding out natural habitat. If not pulled from the soil when young, they form a dense, impenetrable stand of bushes. One plant can produce up to three million seeds per year. Yikes! Some states have even gone so far as to outlaw the sale of these plants. I can understand why.
Curly dock: Is another wind-pollinated weed, creating a taproot that is near impossible to dig out completely. You can try if the soil is moist to use a garden fork to pull it from its moorings. Or cut off the flowers.
Japanese knotweed: Is a large plant native to Eastern Asia, but in North America it has become quite invasive. It is spread by seed or by its rhizomes. But don’t think you can dig up the rhizome as they can grow well over 20 feet across and almost 10 feet deep. Cutting back the top growth several times over the course of the summer and fall will weaken the plant but the most foolproof way to rid yourself of this week is by using an herbicide.