There is an urgent need for woodland expansion to help mitigate climate change and biodiversity loss. However, the process of natural regeneration of forest ecosystems is often slow, requiring active reforestation approaches. Factors limiting regeneration are complex, but there is increasing evidence that natural expansion of woodlands onto sites that have been treeless for a long period of time may be limited by the loss of microbial woodland-soil properties. This study explored the potential role of mycorrhizal associations in facilitating obligate ectomycorrhizal (ECM) tree establishment. We determined the spatial distribution patterns of ECM tree seedlings – Pinus sylvestris and Betula spp. - outwith the existing woodlands, in relation to established dual-mycorrhizal Salix. There was very strong evidence that ECM tree seedlings were more likely to be found growing within groups around dual-mycorrhizal Salix than as isolated individuals, supporting the view that Salix drives the current spatial distribution patterns by supporting tree establishment. We suggest that the ability of Salix to form dual-mycorrhizal associations with both arbuscular (AM) and ECM fungi allows these plants to become established across the open AM dominated vegetation. Over time these plants can become colonised by ECM fungi via aerial spores and then act as a source of inoculum for obligate ECM tree seedlings, which land as seeds in the vicinity of Salix. This study highlights the potential role of dual-mycorrhizal Salix as a nurse plant in supporting secondary forest succession of obligate ECM boreal/temperate woodland species onto adjacent open areas through nucleation. Overall, we concluded that there is potential for existing ECM networks to aid tree establishment and propose a nature-based approach to maximize reforestation efforts by targeting existing symbiotic fungal networks as nucleation points for tree planting. Our findings contribute to understanding the ecological dynamics involved in woodland expansion and restoration.