Information on the health effects of aerosols has focused renewed attention on the presence of very fine and ultra fine particles from transportation and industrial sources. Almost all diesel and smoking car exhaust mass, as well as PAH, falls into these size ranges. Studies on the removal of sub-micron particles via vegetation were carried out using both the UC Davis Mechanical Engineering wind tunnel and a static diffusion chamber. The source was a standard highway flare, which produces particles of unique composition, and the vegetation was chosen to have needles and leaves year round and high surface areas. Redwood, deodar, live oak, and oleander were chosen, all of which are used near California freeways. Removal rates of above 75% were achieved for redwood and deodar branches, which offered significant options for near source mitigation especially on heavily traveled secondary roads on residential neighborhoods. This is an abstract of a paper presented at the 101st AWMA Annual Conference and Exhibition (Portland, OR 6/24-27/2008).