Our Mission:

The Rock Prairie Master Gardener Association, located in Rock County, Wisconsin, is the 42nd association of the Wisconsin Master Gardener Program.

This blog is used to distribute timely information to association members regarding volunteer opportunities, MGV highlights, and other social tid bits.

Horticulture related information is to be directed to the Horticulture Educator or the Plant Health Advisors.

This blog is not for garden related questions.

Thursday, July 21, 2011

Is it an invasive or just a weed?

Dame's Rocket

Many times we are faced with a weedy intruder in our gardens or lawns. Some of these interlopers have been targeted by the state of Wisconsin as invasive species that need to be controlled or eradicated to safeguard plant habitat for other, more desirable species.

Purple Loosestrife

Some of these interlopers are attractive, even beautiful. They add to the ambiance of your garden, so what is wrong with using them in the landscape. And what does invasive actually mean as regards plants, anyway?

Chinese Silvergrass

According to Wisconsin state law, Section 23.22 (1) (c), Stats., “invasive species” means nonindigenous species whose introduction causes or is likely to cause economic or environmental harm or harm to human health.

Garlic Mustard

The WNDR says invasives are:
... plants, animals and pathogens that are "out of place." A species is regarded as invasive if it has been introduced by human action to a location, area, or region where it did not previously occur naturally (i.e., is not native), becomes capable of establishing a breeding population in the new location without further intervention by humans, and spreads widely throughout the new location.

One of the reasons that invasive species are able to succeed is that they often leave their predators and competitors behind in their native ecosystems. Without these natural checks and balances they are able to reproduce rapidly and out-compete native species.

Invasive species can alter ecological relationships among native species and can affect ecosystem function, economic value of ecosystems, and human health.

To learn more about invasive plants visit: What are Invasive Species?

For a list of terrestrial invasives visit: Terrestrial Invasives

Why should we care about invasives? Visit: Invasive Species, Why Should we Care?


  1. I still have a problem considering Dames Rocket a weed! Garlic mustard - no problem pulling out!!!

  2. I have to agree with Janice. Pretty stuff.