Invasive Species Programs


What is an Invasive Species?

Invasive plants are introduced species that can thrive in areas beyond their natural range of dispersal. These plants are characteristically adaptable, aggressive and have a high reproductive capacity. Their vigor combined with a lack of natural enemies often leads to outbreak populations.

What are Invasive Species doing?

  1. Crowding out native species

  2. Fracturing native habitats

  3. Dramatically reducing biodiversity

  4. Depriving birds, butterflies and other animals of habitat and forage

  5. Many birds, butterflies, insects, & amphibians depend on specific plant species.

  6. With each plant species lost, 30 other species also die

Why are Invasives so Pervasive?

  1. No natural enemies – new to our environment

  2. Outcompete many native species in growth speed

  3. Dense colonies capture all the light, water and soil nutrients

Many Ecologists now feel that invasive species represent the greatest current and future threat to native plant and animal species worldwide - greater even than human population growth, land development, and pollution.

ALT’s Invasive Program Strategy

  1. Educate the public about the threat posed by invasive plants

  2. Plant Identification and Risk Assessment

  3. Environmentally Responsible Eradication

  4. Careful Habitat Restoration


Two of the many critical invasive species that are in Fairfield County:



What it does to the habitat…

  1. Garlic Mustard can colonize an area with breath-taking speed, and then competes for light and nutrients with native spring blooming wild flowers.

  2. Garlic Mustard destroys a fungus in the soil that native plants need to get nutrients from the soil.

  3. Garlic Mustard threatens several native butterfly species whose larva eat the native Mustard plants. Because the Garlic Mustard has become so abundant butterflies are placing their eggs on them, but the larva die because of incompatible chemistries.

How to manage Garlic Mustard…

  1. If the soil is moist the plant may be pulled up with the root intact. If the plants have begun to flower they should not be left on the property as they will still disperse seeds.

  2. If the area is too large for hand picking, you can cut them down to ground level in the spring or then apply Round Up in the Fall. Be aware that after cutting the plant will send up new shoots and you will have to make another pass to eradicate.




What it does to the habitat…

  1. Forms acres of impenetrable monocultures

  2. Excludes native wildflowers, herbaceous plants, and new trees

  3. Reduces the litter layer on the soil making it more vulnerable to erosion and loss of nutrients.

  4. Alters soil pH and Nitrogen contents making it less hospitable to native trees and plants.

  5. More important to Connecticut residents, it is a principal host for the tick that causes Lyme disease

  6. Top researchers at the Agricultural Experiment Station proved in field tests that there are up to 7 times more deer ticks on property that has barberry compared to land without.

  7. Eliminating barberry helps to dramatically remove the threat of Lyme disease in your vicinity.


How to manage Japanese Barberry

  1. Cut the shrub to 4-5 inch stubs

  2. Using a wand put a dab of tinted Round Up on the end of each cut stem (tinted so you can see where you have been)

  3. Or use a propane torch to cook the roots to a bright orange

  4. You could also flame the entire bush, but that is more time consuming and costly

  5. Replace with a native species