Seed bombs (a.k.a. “seed balls” or “seed grenades”) are basically seeds contained in a ball of clay, usually mixed with some type of compost, and set to dry. They originated in Japan in the 1940s, and were used extensively by “guerrilla gardeners” in the 1970s. The seeds are dispersed by being thrown (like a grenade), into an area lacking vegetation or otherwise. With the right conditions, the seeds germinate and hopefully grow into plants. For the purpose of this article, I am only focusing on how to make the seed bomb itself.
The list of things you’ll need:
1. Dry red clay (powder)*
2. Dry compost
3. Seeds (native to your area)**
4. Water (to form the clay)
5. Plastic bin (for mixing)
6. Bowls or other containers to hold parts of the recipe
7. Measuring cup(s)
*Note: Dry clay can be found at pottery or ceramic supply stores, or ordered online. It does not have to be red, but it seems red is a popular color. I had NO luck finding dry clay in my local hobby/craft, art supply or hardware store, so I had to use the moist “air dry” clay.
**Note: Using larger seeds can make it more difficult to roll uniformly-shaped seed bombs, so you may want to try smaller-sized seeds first.
1. Set the parts of the ‘recipe’ out in bowls or other containers:
• 5 parts dry red clay
• 2-3 parts dry organic compost
• 1 part seeds
• 1-2 parts water
2. Mix the dry clay, compost, and seeds together.
3. Add water to the mixture very gradually (a drop at a time). You don’t want the mixture to be so damp that it becomes muddy and difficult to form.
4. Knead the mixture with your hands until the right consistency is achieved. It should be the consistency of cookie dough. If you are using the moist air dry clay, you would simply mix it with the compost and seeds at this point.
5. Roll portions of the mixture into small to medium-sized balls, like you would for making cookies. They should be small enough to fit into the palm of your hand.
6. Set the seed bombs out in a dry location for at least a day or two, depending on the size of the bombs. They will dry quicker if set out in the sun.
You are basically done with your bomb making at this point. You can either store the bombs for later use, or ‘commence bombing’ right away.