The use of planted forests as a restoration tool has been shown to improve landscape health and may control invasive plant species by canopy shading. Ulex europaeus (gorse) is an invasive rangeland weed in Hawai`i and forms a monotypic stand covering 1,947 ha on Mauna Kea mountain. Simulated forest canopies of consecutively reduced light levels: full sun, 27, 20, 10, and 2% available light, were used to determine changes in relative growth rate and reproduction of gorse from shading. Productivity, especially fecundity, was reduced at lower simulated light levels (5–10% available light) indicating that light environments provided by planted tree stands would be effective for weed suppression. Planted forests are a sustainable management strategy for controlling woody weeds but stand management has a strong bearing on canopy architecture and improvement of ecosystem services.