The scary feature of invasive plants is their ability to compete above and below the ground and outgrow surrounding plants. The concern, Master Gardener Joe Ann Allen writes, is that invasive plants can over power native species and cause soil erosion, create fire hazards, deprive animal and insect life of food and shelter and have a negative impact on fisheries, recreational areas and public water supplies.
A good example of this negative effect is the spread of the beautifully flowered purple loosestrife. One mature plant can produce more than 2 million seeds, all with a high germination rate. It is estimated that more than 4 million acres are now affected by purple loosestrife’s escape from the garden and it is costing an estimated $45 million dollars annually in control efforts. (October 1, 2010, Page 2B)