You Reap What You Sow: A Botanical and Economic Assessment of Wildflower Seed Mixes Available in Ireland

Abstract

Planting wildflower seed mixes has become popular with individuals and community groups aiming to promote wildlife and enhance local biodiversity. Recently, however, these seed mixes have been criticized with respect to the origin of the seeds and the species they contain. There is a growing awareness that the unintended planting of exotic species may disrupt native ecological networks, introduce aggressive weeds, or facilitate the establishment of invasive species in new localities. In this study, we purchased two packets of twelve brands of wildflower seeds available in Ireland from stores or online suppliers. In total, the 24 packets contained 69,409 seeds weighing 304 g, and represented 92 plant species in 23 families. Only 25% of the seed packets purchased in Ireland originated from Ireland, and only 43% of the plant species we identified are considered native to Ireland. To reinforce this point, the most frequent species, Phacelia tanacetifolia, which occurred in nine of the twelve brands, is not a native Irish plant species. Multivariate analysis identified no obvious grouping of seed mixes based on their intended target group (e.g., bees, butterflies, wildlife), which might be expected had manufacturers followed scientific guidance describing which plants are preferred by which pollinator group. The creation of patches of diverse floral habitats in gardens and urban settings can significantly benefit wildlife and human wellbeing. Our results, however, reinforce the need for caution before using wildflower mixes in attempts to restore or recreate natural or semi-natural plant communities.