Seed balls. In a nutshell, they are a ball of clay and compost with seeds inside. Sounds pretty simple right? Well they are, they really are.

They’re incredibly easy to make, and are a rather excellent way to get things growing in areas that don’t usually have much plant growth.

This month’s 107 Rooftop Garden workshop was all about squishing, mixing and rolling (with the added bonus of a few garden chores and delicious cake at the end).

Seed balls are really simple to make and are great for use in farming, bush regeneration or an easy every day guerrilla gardening technique. (Perfect for city dwellers that would like to see some more green around them or encourage some local bee activity!)

The seed ball is made up of sieved compost, clay, seed and water. Mixed, and rolled together, the balls are then laid out in the sun to set hard.

The idea is to throw them wherever you want to use them. This means letting them set hard enough not to break when thrown.

Once your seed balls are done, they are then thrown out to the areas that they are going to be used. There they’ll sit until the right conditions are met for them to germinate- they won’t germinate straight away.

The seedball will patiently wait until just the right amount of rain comes, good soaking rain, and then it will germinate + get growing.

This technique has been used successfully in many different settings- from farms, rocky hillsides to city centres.

In an urban setting they are perfect little balls to throw into an otherwise unused area.

Guerrilla gardening at it’s best, as the little seed balls simple wait until the conditions are right, before growing whatever green goodness you’ve just used as seed.

What you’ll need to make Seed Balls

• 2 parts sieved compost
• 2 parts clay – if you don’t have any clay in your area, you can use regular artists clay
• Seeds – we used Good Bug Mix from Green Harvest
• Water – as much as is needed

Now you get to mix it all together! If you are using artists clay you’ll need to add some water to it first, giving it a good squish around. Then, add your other ingredients, mixing well.

Tip – when adding your water, do it in small increments. It’s easier to add more water if you need it.

You’ll know it’s the right consistency when you are able to form a tight ball that holds together.

Roll your balls to about a truffle size, or half a golf ball, (there is generally more success with smaller sized seed balls) and then let them dry completely.

That’s it! You’re done.

Seedballs are really simple to put together and great to do with a small group of people -you can get through making quite a number of the balls, and they can also be a really fun gardening activity for kids to do.

Seed ball making resources:

• Seedballs: from Fukuoka to Green Guerillas
• Getting serious about Seed Balls – with bonus video of Costa on our seed ball machine!
• Seed Balls: how to grow trees without really trying

If you would like to come and see the 107 Rooftop Garden for yourself, get in touch with 107 Projects – they run volunteer days.

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Note – of course, don’t throw seed balls where they’re not welcome, or use seeds that are potentially weedy in your area. Use your brain and grow what works, for everyone.