What It's All About
Since weeds aren't all bad, it's good to be able to distinguish the good and the bad from the just plain ugly. Understanding weeds can help children build a new relationship with plants in general and gain respect and knowledge of biodiversity.
Wildflower or Weed?
There are many ways to teach students about plant identification. Begin the discussion by asking the children if they know the names of any weeds. Why do they think they are weeds? Many people believe dandelions are weeds, but many children think they are beautiful wildflowers. Using books, homemade flash cards, or the Internet, begin looking for local examples of wildflowers and weeds. When learning how to identify plants, pay attention to the following characteristics:
Number of petals on flowers and how the flowers are arranged on the plant
Shape and distribution of leaves
Stem: is it a vine, does it grow upright, or does it cover the ground?
Reproduction: does it grow from seeds, bulbs, or tubers?
Habitat: is it sunny or shady, is the soil sandy or more claylike, what are the surroundings like (prairie, swamp, woodlands, ditches, etc.)?
These characteristics can help you identify plants because many similar plants share features. It also helps to know as much information as possible to make it easier to look for the plant in a field guide or explain it to a botanist.
Have each student choose two local flowers to research. They should define as many of these characteristics as they can. They should also identify whether it is native or non-native and if it's helpful or a nuisance. Is it a wildflower or a weed? Why? Each child should do a quick presentation about their two plants. Then have each child draw or paint a picture of the flowers that you can cut out and “plant” along the bottom of the wall in your school hallways for a beautiful wildflower garden!
According to the National Park Service, about 5,000 plant species in the United States alone are considered to be at risk of extinction. Invasive species are the second greatest threat to native species after direct habitat destruction from development.
Wanted: Dead, Not Alive
According to the Bureau of Land Management, “Legally, a noxious weed is any plant designated by a federal, state, or county government as injurious to public health, agriculture, recreation, wildlife, or property.” Noxious weeds are the worst form of non-native, invasive weeds as they cause such a serious threat. Here are some interesting and Earth-friendly ways that people have found to get rid of the worst noxious weeds. They are known as biological control methods because they use natural ways to get rid of weeds.
Bugs kill weeds. For some types of weeds, researchers study what their native habitat is like and what types of organisms, like bugs, keep them under control. After years of careful research, to make sure the newly introduced bug will not harm anything but the target weed, scientists release the bug into the environment so it will naturally reduce the invasive species.
Goats eat weeds. Goats can eat plants that are poisonous to humans and other animals. Their hooves aerate and till the soil and trample in their own fertilizer. Even the city of Los Angeles recently rented goats to eat weeds in downtown green spaces. Visit http://goatseatweeds.com to learn about this innovative form of weed control.
Fish eat weeds. Many weeds are aquatic, meaning they live in water and disrupt the ecosystem. Fish have been used to eat invasive species, in much the same way bugs have been used. Scientists research what type of fish ate the weed in its natural habitat. Then they release sterilized fish into the water to eat the invasive weeds.
All of these methods help control noxious weeds without having to use toxic chemicals.
Which plants are noxious weeds in your area? Have the students make “Wanted” posters of them. The posters should include a picture of the plant, its Latin name, any “aliases” it may have, where it's commonly found, and the threats it poses to the environment or human health. You can search online to learn about noxious weeds in your community.
For nonpoisonous, nonprickly noxious weeds, get your students, staff, and parents in the habit of picking them and throwing them away when they see them. Choose even just one weed that your school can commit to picking. Post signs about it around the school with a picture so everyone has a regular reminder of what to look for.