Competing vegetation control (CVC) following timber harvest has an immediate and lasting positive effect on crop tree growth by increasing water, light, and nutrient availability to crop trees. We are measuring soil N pools, N leaching, and foliar N of planted Douglas-fir following CVC with herbicide at two sites in the Pacific Northwest to determine the effect of CVC on N cycling. Increased nitrate leaching was observed at both sites following CVC in the first year after planting, but significant effects were only observed at the high soil N site in the second year. Summer potential net N mineralization measured in a laboratory incubation was decreased by approximately 40% following CVC, but available N measured in situ was approximately two times higher in CVC. Increased in situ available N is most likely due to increased N mineralization associated with increased soil temperature and moisture following CVC, as well as reduced vegetative uptake from competing vegetation. Increased available N was utilized by Douglas-fir crop trees which had significantly higher foliar N following CVC in the first year after planting, but only the high N site maintained this increase into the second year. Douglas-fir growth was correlated with foliar N status, demonstrating the positive effect of CVC on tree growth. Reduced N mineralization potential and increased N leaching can potentially reduce long term soil quality by reducing both available N supply and total soil N. However, the magnitude of effects observed here appear to be dependent on total soil N, which may act as a buffer to alterations of the N cycle following CVC. Although continued measurement is needed to determine the long term effects of CVC on soil N, it appears that the large increases in growth associated with CVC outweigh any of the short term N losses measured thus far.