Have you ever seen a round bump in the middle of a goldenrod stem? Or a series of warts on a grape leaf? How about a bright orange spiky ball on a cedar tree or a pine cone on a willow tree? These are all examples of galls. Galls are a strange plant growth caused by insects, injury or microorganisms.

Here are some simple activities and questions to do with youth to learn about galls:

1. Walk through a garden, prairie or woodland and ask children to look for strange things on stems, branches or leaves of plants. Look for things that are different. (This might lead to finding many things other than galls.) Why are they there? What caused them? Do you think that “hurts” the plant? Does it belong there? What might be a fun name for the stuff you find?
2. Before removing the gall from the plant, ask children to observe. Where is it on the plant? Is it only on one part of the plant, such as the leaves or stems? Why isn’t it on a different part of the plant? Are there any holes in it?
3. Remove the gall from the plant. What might be inside? Will it be hollow? Will it be different or the same as other parts of the plant?
4. Carefully cut open the gall and examine what is inside. You might not find anything, or you might find an insect or a larva. You might find evidence that something was eating, but no actual insect. You might find insect poop, called frass, inside the gall.
5. After you have examined the gall, ask some of the same questions you did at the beginning. Does the gall “hurt” the plant? How would you know?
6. What does the gall do for the insect or microorganism that helped create it? Might it provide protection or food?
7. Do you think there are other animals that might eat the insects inside the gall? (Galls can be a food source for birds, such as woodpeckers, during the winter.)

Enjoy exploring these strange manifestations outdoors and use it as a chance to teach inquiry-based science to the young people in your lives. Michigan State University Extension encourages families, daycares, school activities, 4-H clubs or any group working with young children to conduct these experiments. The focus of these lessons aren’t to simply impart knowledge, but to facilitate the joy of discovery and the exploration of the world around us. This is not designed to “give youth the answers,” but to empower them to ask questions and figure things out on their own. When a young person asks a question, resist the urge to answer it, and instead ask, “What do you think?”