Seed bombs have been a favorite craft of amateur gardeners (and their small children) for a long time now, and I’ve always loved the idea of guerrilla gardening. The romantic notion of tossing homemade wildflower “bombs” into unloved lots and along roadways…what’s not to love?
I finally decided to make my own milkweed seed bombs, but I needed to confront my own skepticism. You see, I don’t want to be skeptical about the true effectiveness of seed bombs, but a golf ball-sized ball of hard-as-rock clay just doesn’t seem like a great way to germinate seeds that’ll grow into beautiful wildflowers. And I’m not the only one!
But with some extra research beforehand and a few instinctual tweaks to the myriad recipes I found online, I’ve made about two dozen milkweed seed bombs that I’m optimistic will grow into lively plants for my local pollinators come next Spring.
What You’ll Need:
- Rich compost
- Clay (air dry, powdered, or natural from your area). If using natural clay from your area, make sure it’s free of any possible pests.
- Swamp milkweed seeds*
- Muslin or burlap sachet for storage or gift-giving
*When choosing seeds, be sure to do your research and find out what’s native to your region. If you plan to use your seed bombs outside the confines of your own garden, or if you’re making a gift, always go with native varieties! I’m in New York State, and so I know to go with swamp milkweed (Asclepias incarnata) seeds, which are native to the Northeast.
Step One: Mix the Clay into Your Compost
Not gonna lie, this first step was a pain. I chose to use an air-dry modeling clay instead of powdered clay, so breaking it into smaller bits to mix into the compost was really hard on my wrist. If I were to do this project again, I’d try to find some powdered clay, which you’d then mix in with your compost and a bit of water to form the seed bombs.
For my purposes this first time, I found that lots of folks recommend not following recipes that call for much more clay than soil. Though my seed bombs did end up being mostly clay, I was careful to only mix in small amounts of clay at a time, kneading the mixture like a bread dough to incorporate as much compost as possible. Once I had a crumbly consistency I was happy with, I moved on to forming the bombs.
Step Two: Form Small, Dime-Sized Bombs
Most seed bomb recipes will tell you to form your mixture into golf ball-sized bombs. While this may sound reasonable, bigger does not always equal better! In my research, I found some great advice to make your seed bombs smaller — about dime-sized — for more effective germination and a greater likelihood of success.
In forming my dime-sized bombs of clay and compost, I tried to incorporate as much soil as I could. Though they did end up being mostly clay due to the nature of the particular modeling clay I chose, I think the smaller size will help to break down the materials faster and more uniformly when the time comes for the seeds to germinate and sprout in the garden. We’ll see what happens, and I’ll keep you posted!
Step Three: Press the Milkweed Seeds into the Compost/Clay Bombs
I chose to first mix all of my compost and clay bombs before adding the milkweed seeds, which may (or may not) have been a wise choice. On the one hand, if your seeds need light to germinate, you don’t want them buried in the middle of your seed bomb. To me, if I’m making much smaller seed bombs with the goal of having them incorporate into the soil easier, then having more exposure to sunlight is a good thing. It was difficult, however, to fold them into the sides of the bombs that had already started to harden.
I eventually got the hang out of it by using my nail to cut a slice in the side and sticking a milkweed seed in there, making sure to close it up around the seed as much as I could. I also didn’t anticipate the seeds being so large and flat. Full of surprises, this project!
Each seed bomb ended up with between 1-3 milkweed seeds, which worked out perfectly for the number of seeds I had between two packets and the number of compost/clay bombs I had made earlier.
Step Four: Leave to Dry at Least 24 Hours
Whether you use dry clay mixed with water or a wet clay like I did, you’ll need to let your fresh seed bombs air dry for at least 24 hours. This should be enough time if you make smaller bombs, but if yours are larger, you’ll need closer to 36 hours for them to dry.
In the meantime, pour yourself a glass of rose in your favorite fancy glass and pick up a breezy summer reading book (I’m making my way through Joyland by Stephen King), or dive into Season 3 of Stranger Things. Relax! It’s hot AF outside right now.
Step Five: Put Together as a Gift or Store for Later
At long last, your final step is to store your milkweed seed bombs in a cool, dry place until you’re ready to throw them. Because I planned to gift about half of my seed bombs, I picked up a packet of two attractive burlap sachets at AC Moore when I bought my modeling clay. You could also use a muslin spice sachet, but do think about how much loose soil you’ll have, and if it’ll come through the fabric you’d like to use.
I put together a little planter gift basket for a fellow gardener as part of a surprise bachelorette brunch a friend organized this past weekend, and I know these milkweed seed bombs have found a good home! Because it’s already mid-summer, I chose a few different seed varieties that can be planted in late summer or early Fall to accompany the seed bomb sachet.
Milkweed seeds are perfect for this collection because they too should be planted into the Fall, to then bloom in the Spring. They need a cold, wet period to stratify and aid in germination, so mid to late summer is the perfect time to spend some time crafting milkweed seed bombs. All together, it makes for an inexpensive, yet elegant gift that I’m sure the gardener in your life would also love.
Final Thoughts
Though I was skeptical at first and some steps ended up being tougher on my hands and wrist than I anticipated, I’m glad I did my research beforehand, and that I followed through with this project I’ve wanted to try for a long time. You can make seed bombs with other wildflower varieties, and with some experimentation, I’m sure it can become a fun ritual to look forward to each year.
Just keep in mind your soil to clay ratios, the number of seeds in each bomb, the size of your seed bombs, and where you’re tossing them for your greatest chance of success. Bringing milkweed back to our butterfly populations is for sure a worthy endeavor, and why not have some fun with it? Bombs away, bitches!