Fossil fuel exhaust contains CO, CO₂, SO₂, NO, in addition to particulates (soot). It was hypothesized that ryegrass seeds (Lolium multiflorum) when exposed to diesel fuel exhaust would have fewer seeds germinate and sprout. Exhaust collector pans were created and one hundred ryegrass seeds and water were added to each pan. Fossil fuel exhaust was added to two exhaust collector pans. A third pan with no exhaust was prepared. The three pans were placed in a greenhouse for eight days. The seed growth from each pan was calculated and recorded. The mean growth for the control was 100%. The growth for the gasoline exhaust was 85%. The germination for the diesel was 67% and was 19% for sprouting. The t-test analysis of the data had a p-value of 0.0001. The hypothesis was supported because the fossil fuel exhaust did affect the growth of L. multiflorum.