Seed bombs can be used to green up fallow areas in cities almost in passing. Here’s how you can make the green bombs yourself.
The term seed bomb actually comes from the field of guerrilla gardening. This is the term used to describe gardening and cultivating on land that is not owned by the gardener. This phenomenon is finding more and more followers, especially in the big cities. Their weapon: seed bombs. Whether homemade or bought ready-made: They can easily be used to green up fallow areas in public spaces such as traffic islands, green strips or abandoned lots that are difficult to access. A targeted throw from a car, down from a bicycle or conveniently over the fence is all it takes to make plants sprout from the ground.
Where can you use seed bombs?
Seed bombs should only be used in urban areas. They have no place in nature reserves, agricultural land, private property or the like. However, in cities they are a wonderful way to make the city greener and promote biodiversity. Before the law, planting on public space is property damage. Likewise, seeding on private property or fallow land is prohibited. However, criminal prosecution is still very unlikely and rather rare.
The history of seed bombs
The seed bomb was invented by a Japanese rice farmer named Masanobu Fukuoka, a proponent of nature-based agriculture. He used his nendo dango (seed balls) after World War II primarily to sow rice and barley. Visitors who came to his farm in the 1970s then brought the idea of seed soil with them to the West and thus carried it around the world. They were also first used in the 1970s, when American guerrilla gardeners began to use them to green up New York. They also gave the seed bombs their name, which is still in use today.
How do seed bombs work?
Throw, water, grow. That’s basically all there is to it. The best time to “blow up” seed bombs is in the spring, ideally just before rain sets in. A seed bomb is basically soil, water and seeds. Many add some clay, like clay powder or clay soil, which keeps the balls in better shape and protects the seeds from animals such as birds or insects, as well as adverse weather.
What seeds are suitable for seed bombs?
If you want to make seed bombs yourself, you should use seeds from native plants. Non-native plants can become a problem, as they have no natural competition in the country and thus proliferate uncontrollably. They upset the ecological balance. The most famous example of such an invasive species is giant hogweed. Be sure to use only untreated seeds and select plants that can handle urban climates. Common marigolds, lavender, marigolds or cornflowers have proven successful, as have coneflowers and mallow. Wildflower mixes particularly attract bees, bumblebees and butterflies, so benefit wildlife at the same time.
Herbs and various vegetables can also be planted out by seed bomb. Rocket, perennial wall-rocket, nasturtium, chives or even radishes are best spread by seed bomb and, provided they get enough water, thrive even in the city without much intervention.
For shady locations, plants such as cranesbill or borage are recommended. Wild grasses, thyme or corn poppy do very well with little water.
How to make your own seed bombs
Meanwhile, seed bombs are also available in many stores. The bombs range from sunflowers to butterfly meadows to wild herbs. But you can also easily make seed bombs yourself. As a rule of thumb, you will need ten seed bombs for one square meter.
- 5 handfuls of clay powder (optional)
- 5 handfuls of soil (normal plant soil, mixed with compost if you like)
- 1 handful of seeds
First, finely sift the soil. Then mix the soil with the seeds and clay powder well together in a large bowl. Add water drop by drop and knead the mixture until you have an even “dough”. Then shape it into balls about the size of a walnut and let them dry in a place that is not too warm and well ventilated. This usually takes about two days. If that takes too long, you can also bake the seed bombs in the oven at a low temperature. You can toss the seed bombs immediately afterwards. But you can also store them in a cool and dry place for up to two years.
Tip for advanced
Seed bombs become especially durable and resistant if you cover them with a coat of clay. You can buy this ready-made or mix it yourself using clay powder and water. Form a bowl and fill the mixture of soil and seeds inside. Then close the shell and shape it into a ball. After drying, the seed bombs are rock hard and well protected against wind or animals.