Urban houses play a central role in the conservation of woody biodiversity. However, there are not enough studies that have determined the structure of woody plantations in houses, as well as the services provided and the causes of their mortality. This study, conducted in the city of Maradi in Niger, more precisely in the Zaria II district of Commune 2, aims to determine the number of woody species, their values, and the causes of their disappearance. To achieve this objective, socioeconomic and botanical surveys were carried out using a questionnaire administered to 73 heads of households. The results revealed a total of 34 woody species inventoried in the houses, belonging to 21 families and 30 genera. Fabaceae (11%) are the dominant family. These tree species provide four categories of services, including only one cultural service, which is beauty (8.82%), regulatory services: fight against erosion (5.88%) and fight against wind (10.29%). The supply services cited are pharmacopoeia (16.17%), human food (14.70%), firewood (4.41%), shade (17.64%), and finally, support services: CO₂ capture (5.88%) and comfort (13.23%). The indices of floristic diversity show that the Zaria district is rich, with a Shannon index of 2.94 and Piélou equitability of 0.83. We recorded 76.47% of the woody exotic species (26 species) and 23.53% of indigenous woody species (8 species) with strong significance (P < 0.05). The equality of expectations test (paired observation) carried out on the number of species and the socio-demographic characteristics (sex, marital status, number of women, number of children, mode of acquisition) reveals that there is a significant relationship between the number of species and these characteristics (P < 0.05). However, the test on the number of species and mode of acquisition shows that there is no relationship between them (P > 0.05). This study will lead to a better understanding of the place of woody species in houses. The findings of this study can be applied toward the local and global efforts to conserve tree biodiversity in dryland cities in way that the tree biodiversity will provide a variety of ecosystem services to the urbanites for green and sustainable cities. The study recommends also the massive use of native tree biodiversity in tree planting initiative in the houses for sustainable biodiversity conservation.