Leafing and flowering data for lilacs and honeysuckles 1956-2014

The dataset is comprised of leafing and flowering data collected across the continental United States from 1956 to 2014 for purple common lilac ( Syringa vulgaris), a cloned lilac cultivar (S. x chinensis ‘Red Rothomagensis’) and two cloned honeysuckle cultivars ( Lonicera tartarica ‘Arnold Red’ and L. korolkowii ‘Zabeli’). Applications of this rich legacy dataset range from detecting regional weather patterns to understanding the impacts of global climate change on the onset of spring at the national scale. While minor changes in methods have occurred over time, and some documentation is lacking, the dataset has proven robust in combination with climatic data for detecting spatio-temporal changes in the onset of spring.