Yellow starthistle, Centaurea solsitialis, is an invasive weed species that is quickly making itself at home in California and the western United States. It has no natural enemies in the US, and yet possesses many characteristics which make it a good invader. Yellow starthistle plagues the sandstone grassland at Jasper Ridge, but for some reason does not contaminate the nearby serpentine grassland. In this study, I tested whether yellow starthistle grew in serpentine soil under experimental conditions, defining growth in terms of seed germination, number of leaves per seedling, and seedling size. Nutrient deficiency is often cited as the reason serpentine grassland is free from the wrath of yellow starthistle, and in this study I also investigated whether increased nutrients, in the form of fertilizer, significantly influenced growth in the serpentine. I found that significantly more seedlings germinated on serpentine than on non-serpentine soil. Adding fertilizer to the serpentine soil significantly decreased the number of the serpentine seedlings, but significantly increased their leaf size and marginally increased the number of leaves a seedling possessed. In addition, the interaction between soil type and fertilizer proved to have the greatest effect on leaf size. Soil type had no effect on the number of leaves per seedling.