How to Make Seed Bombs: A Fun Guerrilla Gardening Project

Whether you are looking for a fun DIY project to do with kids or want to plant an instant flower garden in some abandoned space, this guide will teach you how to make clay seed bombs. It doesn’t take long to make the world a greener place!

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Fun DIY Gardening Projects

I love a good DIY garden project! They can be so fun, save money, and help to engage friends and family in gardening. 

That’s why I’ve shared some of my favorite projects with you, like how to make a DIY fruit and vegetable wash, how to make compost tea, how to Florida weave tomatoes, how to make a homemade starting mix for seeds, chitting potatoes, and how to build a cattle panel trellis. 

Why I Like to Make Seed Bombs

Creating seed bombs is an easy and enjoyable way to contribute to the environment. Whether you're a gardening enthusiast or a nature lover, these little earth-friendly grenades can make a big difference in supporting local ecosystems. 

Seed bombs are a great way to wage war on that ugly vacant lot, neglected spaces, or even your own backyard! This inexpensive craft project is fun for kids and adults, and it is a great way to beautify the neighborhood one bomb at a time. They also make great gifts for gardeners!

For more guerrilla gardening ideas, check out these videos on spreading 4 million native wildflower seeds and guerilla grafting edible fruit onto invasive ornamental trees. Guerrilla gardening has never been so fun!

Picking the Right Seeds For Your Seed Bombs

When choosing seeds for your seed bombs, it's essential to consider your local climate and soil conditions, and the specific goals you have for the area where you plan to disperse them, selecting quality seeds that will thrive in those conditions. Keep in mind that most vacant lots don’t have great-quality soil. 

The following seeds are usually good options for seed bombs.

Wildflowers 

Native wildflowers are always a great choice because they are adapted to your region's climate and soil! Some popular wildflower options include:

• Black-eyed Susan

• Bluebonnet (in Texas)

• California Poppy

• Purple Coneflower Milkweed (for supporting pollinators and monarch butterflies)

• Lupine

• Coreopsis

Herbs

Many herbs are well-suited for seed bombs and can attract beneficial insects or be harvested later for culinary or medicinal purposes. Consider these herbs:

• Basil

• Cilantro

• Dill

• Chives

• Lavender

• Mint

• Parsley

Pollinator-Friendly Flowers 

To support pollinators, choose flowers that attract butterflies and bees:

• Butterfly Milkweed

• Bee Balm

• Echinacea (Coneflower)

• Lavender

• Salvia

Low-Maintenance Plants

If you're looking for plants that require minimal care, opt for hardy, drought-tolerant varieties. Cover crops are another great choice because they are often low-maintenance and can rehabilitate poor soil! Consider using these seeds:

• Succulents (e.g. Sedum, Sempervivum)

• California Poppy

• Wild Bergamot

• Clover

• Cover Crop Mix

Shade-Tolerant Plants 

For areas with partial or full shade, consider shade-tolerant wildflowers such as:

• Columbine

• Ferns

• Hosta

• Wild Ginger

Native Grasses 

Grasses play a crucial role in many ecosystems. Include native grass seeds for added diversity:

• Little Bluestem

• Buffalo Grass

• Switchgrass

• Indian Grass

Supplies Needed to Make Seed Bombs

You only need a few simple ingredients to make seed bombs.

• Bentonite Clay - You can use Bentonite clay powder or air-dry clay. You will need 5 teaspoons. 

• Worm Castings - Five teaspoons of worm castings will be enough to gently fertilize the seeds when the seed bombs dissolve. You can also use fine-finished compost instead.

• Seeds - Use the lists above to help you select the best seeds for your seed bombs. Each batch of seed bombs will require 2 teaspoons of seeds.

• Water - You will need water to moisten the mixture. There’s no specific amount because you never know exactly how much it will take to achieve the right consistency.

• Mixing Bowl - Nothing fancy here; you just need a bowl or container to mix your ingredients in. (A spoon to stir them all together is optional, or you can get messy and use your hands.)

• Measuring Spoons - Grab some measuring spoons to accurately measure out your ingredients.

How To Make Seed Bombs

Follow these simple steps to make seed bombs:

1. Pour Clay Into Bowl - Use measuring spoons to put 5 teaspoons of clay in the bowl. Pro-Tip: No matter how big a batch of seed bombs you make, just make sure you maintain a 1:1 ratio of Bentonite clay to worm castings.

2. Add Worm Castings - Measure and add 5 teaspoons of worm castings to the bowl. Don’t skip this step, or the clay ball will dry too hard and not break apart to release the seeds.

3. Add Seeds - Measure and add 2 teaspoons of your chosen seeds to the dry mix in the bowl.

4. Mix Ingredients - Mix the ingredients in the bowl, gradually adding water as you mix until you have a tacky, pliable putty. Pro-Tip: Don’t add too much water at one time! Just add a little bit of water, mix as you go, and add a little more water as needed.

5. Form Balls - After ensuring that the seeds are evenly distributed, roll the mixture into small balls, about 1-2 inches in diameter.

6. Dry - Place the seed bombs on a cutting board, a wire cooling rack, a cookie sheet lined with parchment paper, a table, or a windowsill, and allow them to dry for 24-48 hours in a warm location with good airflow. They should harden and hold their shape.

7. Store or Disperse - Once dry, your seed bombs are ready for action! You can store them in a cool, dry place until you're ready to distribute them in gardens, vacant lots, or other suitable locations.

8. Plant Seed Bombs - Simply toss the seed bombs onto bare soil, and with rain and time, they will break down, allowing the seeds to germinate and grow into vibrant plants!

If you aren’t ready to use them right now, you can put seed bombs in a nice box and gift them, or save them for your next gardening season.