Make Seed Balls to Green Your World

Kim Moldofsky is the publisher of The Maker Mom and STEM Kids Chicago.

Spring has sprung. Chicago's many April showers resulted in beautiful May flowers. Even so, there are bare patches in my yard and a few drab spots around town. Seed balls are a fun way to try to fill them in. A seed ball is a palm-sized collection of plant seeds, potting soil (or compost), and clay that you toss into a garden, or, even better, a vacant lot to create green space. Although recently gaining in popularity, some believe they’re just a new take on an ancient agricultural concept.

Seed balls may seem fanciful, but the U.S. military put out a call this year for them in early 2017. Technically, the military is seeking “Biodegradable Composites with Embedded Seeds for Training Ammunition.” The goal is to grow environmentally beneficial plants that eliminate ammunition debris and contaminants. The submission deadline has passed, but there’s still plenty of time to grow this concept into an entry for the 2018 Young Scientist Challenge.

Seed balls (sometimes called seed bombs) are easy to make. In fact, making seed balls is a great group activity, so it’s ideal for an end-of-year project.

As you work the clay, you and your young scientists can discuss the important role of plants in preventing erosion, what flowers are native to your area and why they thrive in local conditions, or other topics related to ecology, botany, and conservation. You can talk about the mechanics of the “explosion” as soil and seeds scatter upon impact, overcoming the holding power of the clay. The students can surmise what might happen to the seeds after they’re cast. How many will be eaten by birds? How many will take root? How many will wither in the sun? Why do plants create sooo many seeds? What percentage of seeds actually grow into another plant?

Be sure to use seeds for native grasses and flowers in order to increase the chances that your greenery will thrive in your environment and won’t introduce invasive species. This is also a good opportunity to talk about how invasive plants colonize new regions and the impact that they have on natural and human lives.

How to Make Seed Balls

  1.     Pinch off a piece of clay so you can make a sphere between 2.5 and 4 centimeters. (Think: just a bit smaller than a golf ball.)
  2.     Flatten the sphere into a circle.
  3.     Pour on a teaspoon of compost or soil.
  4.     Sprinkle between five and 10 seeds on top of the soil. Exact counts are not required.
  5.     Fold the circle’s edges together to make a seed taco and pinch the edges tight. A seed taco would do the job, but to stay true to the name seed ball:
  6.     Roll your creation into a sphere again. The clay’s job is simply to hold the soil and seeds together. It’s okay if the soil or seeds poke out a bit.
  7.     Let your seed ball dry for two or three days.
  8.     After it dries, find a suitable spot (not on private property without permission) and give the ball a good toss in the air. Whether you want to discuss the influence of gravity is up to you.