Sculptural Seed Bombs
Spring blooms are one of our favorite parts of the season each year. One way to prepare for spontaneous spring planting is to create seed bombs that you can place outside. They can be made in almost any form, ranging from spheres that are easy to toss into garden spaces or even small sculptures to temporarily decorate your garden bed or planters.
Seeds bombs are more than just fun! They protect seeds from erosion, foraging critters, and harsh environmental conditions, giving the plants a good start to life.
Tips and Tricks for Making Seed Bombs
When choosing seeds, consider the environment of where you’ll drop your seed bomb. Be sure to select plants that require similar growing conditions, including light and soil moisture. We recommend using plants of similar height, too, so none are lost later in the season, or single species.
If you’re using annuals, plant after the last frost on a patch of earth where the weeds, grass and unwanted plants have been removed to give your seedlings the best germination rates; however, prep isn’t absolutely necessary as the soil and clay in your bomb will help your seedlings establish. Japanese farmer and author, Masanobu Fukuoka, who encouraged natural farming methods such as no till, is credited for creating “seed balls” to revegetate landscapes and did not believe in “excess actions!”1
If you’re using perennials, be sure to: 1). use species native to your region; 2). toss your seed bombs during the appropriate season to ensure seeds that require stratification receive it; and 3). be patient! Perennials are known to “sleep” in their first year, “creep” in their second, and then “leap” in their third, so patience is key.
Last tip: Use seeds in moderation to avoid competition among the seedlings and the need to thin them and remember to water your plants and keep them moist until they’re established.
You will need:
- Ceramic or air-dry clay (if using air-dry clay, be sure to look for all-natural kinds without synthetic ingredients)
- Potting soil
- Seeds: see above tips for considerations in choosing seeds; a recommended combination is zinnias, spider flowers (Cleome) and verbena bonariensis
- Optional: A variety of small cookie cutters or molds, clay shaping tools
Select your cookie cutter or mold—if you plan to use one—to shape your seed bomb. Break off enough clay to fill about 2/3 of the mold/cookie cutter. If you are not using a mold, you can still start with clay about 2/3 of the size of your intended seed bomb. Press the clay into a small cup shape.
Pro tip: for seeds to sprout effectively, seed bombs should be small and no more than a couple of inches thick in any direction.
Fill your pinched clay with a small amount of potting soil (use about half the amount of potting soil as you used clay), then sprinkle a small amount of seeds on top of the soil.
Enclose the soil and seeds inside the clay by pinching the sides up and together. It’s okay if the soil and seeds mixes with the clay during this and the next step.
Form your ball of clay into the shape of your choice. You can press it into your mold or cookie cutter, roll it into a ball, or create a small sculpture. As noted above, don’t worry about the soil, seeds and clay mixing together during this process. Allow the seed bombs to dry for at least a full day until they are hardened. They will shrink slightly during the drying process and will easily pop out of their molds.
Now you can share or plant your seed bombs! They are sturdy enough to gather in a box or bag to give as a gift. You can place them in a planter full of soil or a garden bed. Water them as you would planted seeds and watch your seed bombs dissolve into the soil. Within a few weeks you should begin to see sprouts emerging!
1 “About Masanobu Fukuoka.” Masanobu Fukuoka Natural Farm. https://f-masanobu.jp/en/