Guerrilla gardeners — those stealthy green thumbs who tend to neglected urban land, often under cover of darkness — may soon have a new weapon in their arsenal: seed bombs dispensed from old bubble gum machines. The concept, called Greenaid, is the work of L.A. designers Daniel Phillips and Kim Karlsrud and San Francisco landscape architect David Fletcher. Their modified machines will offer a choice of three mixes — tiny balls of soil and seed formulated for different habitats. Part of Fletcher's contribution was designing photo illustrations that imagine the dispensaries at spots such as along the Los Angeles River. The goal is to deploy 10 Greenaid machines by mid-May, Phillips said. The first is to be stationed outside the Fifth Floor Gallery in L.A.'s Chinatown during business hours. More information: thecommonstudio.com.

— David A. Keeps