Urban green contributes to enhanced well-being and overall quality of life in urban populations. The concept of place attachment provides an established avenue for exploring the intricate connections between urban environments and personal experiences. Building on the notion of place attachment, we investigated the perceptions of horizontal and vertical urban green by introducing a novel Urban Green Attachment (UGA) scale. A cross-sectional study using an online survey in German, measuring emotional, cognitive, and behavioral relations to urban vegetation, was conducted among 164 adult inhabitants of the Volkert quarter in Vienna, Austria. Using principal component analysis, we found that the UGA scale was a reliable measure of attachment to urban green, with ten items within the “attachment” factor. Study participants highly valued vertical green, but did not differentiate their attachment to it from horizontal greenery within the specific local context and by design of the measures we used. Thus, further studies and ethnographic investigations, preferentially accompanied by methods such as walking interviews, are needed to test the scale for other populations and settings. The UGA scale emerges as a valuable tool for advancing understanding in this critical area, given the current climate change-driven transformations of cities, building on the creation of green infrastructure.