Set one foot outside and you'll likely have weeds or wildflowers in view. Even deep in the big city, weeds find their way into cracks in the sidewalks and roads. They are tenacious little plants, so it shouldn't be hard to find some when you get outside.

Schoolyard Scavenge

You may be surprised how many types of weeds and wildflowers are trying to thrive on your school grounds. Take your students outside for an afternoon of scavenging to take a closer look at the mini-ecosystem you walk through every day. A great way to collect and organize your specimens is by creating an herbarium. An herbarium is simply a collection of plants. You'll need the following supplies:

Have your students scout out the weeds by looking for plants that seem out of place. Look for ones that are climbing trees, sprouting up through cracks in cement, or growing in large patches in the grass. When students find one, they should sit down by it and start writing down information about the plant as they wait for you to arrive to snip the sample. They should note the soil conditions, surroundings, plant size, shape, and color. They can even draw a picture if they'd like. Place the sample in a wax paper bag, and be sure to include any leaves, flowers, fruit, and roots if possible.

Return inside to create formal identification cards for your herbarium. They should include the plant's Latin and common names, where it was found and when, a description of the weed, and its typical habitat. You can also include any other information you deem relevant or interesting. As your students make the identification cards, you can use an iron to press the specimens into the wax paper bag, which should help preserve them for studying for at least a few months. Remember to keep a thin linen cloth between the iron and the bag so the bag doesn't stick to the iron.

Go Native

Visit a local nature reserve to explore your region's natural landscape. Call in advance to get a list of native plants and a list of invasive species. Study these plants before you take your trip so your students know what to look for when you arrive. By just looking at a picture of each plant, can they tell which is a weed and which is a native wildflower? How does the park control weeds? How have they observed differences in the landscape with the presence of the weeds? Do they push out other plants? How do the local wildlife and birds respond to the weeds? Is there anything that students and other citizens can do to help stop the spread of invasive species?