Flower bombs, also called seed bombs and seed balls, are compact balls of soil and seed mixtures that you throw into vacant lots and other barren areas. Rainfall breaks the balls apart, effectively planting the seeds. Flower bombs are part of a movement called guerilla gardening. Be aware, though, that flower bombs are not welcome in every city. While they seem innocent and pretty, they can have legal implications in terms of private use of public land. A 2010 article by Bob Shaw of TwinCities.com notes that city officials in Woodbury, Minnesota, east of St. Paul, list neglected plants as one of the reasons to oppose the use of flower bombs. Ensure your community allows the use of flower bombs before distributing them.
Seeds
Of course you're going to need seeds for a seed bomb, but it isn't a matter of just tossing a random packet of seeds into the mix. Aim for seeds of flowers native to the area and particularly well-suited to local weather and growing conditions. Avoid those that are considered invasive or a nuisance. Remember that unless you're planning to revisit the scene to repeatedly care for the flowers, they probably won't receive regular rainfall or fertilization and will need to be hardy enough to survive those conditions. Check with garden centers as well as county and university extensions for what flowers would be considered appropriately low maintenance.
Water
While a flower bomb is thoroughly dried out before use, you still need to add water in order to get all the ingredients to stick together. Trying to assemble a flower bomb without water is like mixing ingredients for bread without adding water; you'll end up with a disintegrating, crumbly mess. Add the water after mixing all the dry ingredients together. Roll the mixture into balls and set them out to dry.
Soils and Compost
The type of soil or soil substitutes, and whether or not you use compost, vary from recipe to recipe and from area to area. Many recipes call for the addition of clay, and a clay/compost mixture is quite common. Even if two recipes agree on a type of medium, the exact type can vary. "The Times Record News" of Wichita Falls, Texas, says a local seed bomb business relies on clay from the Red River; Andrea Bellamy of HeavyPetal, however, advocates using dry, powdered pottery clay.
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