Seasonal Dynamics of Functional and Ornamental Performance of Nine Perennial Taxa in an Established Urban Planting

Herbaceous perennials contribute to the functional stability and ornamental quality of urban plantings, but these dimensions are rarely assessed together. This study evaluated nine perennial taxa in an established municipal planting in southern Poland. During a 370-day period fortnightly observations documented canopy development, flowering, foliage persistence, winter interest, overwintering and stand retention. Ten performance indicators were calculated and taxon profiles were compared using hierarchical cluster analysis. Canopy Closure Time ranged from 43 days in Rudbeckia fulgida ‘Goldsturm’ to 109 days in Imperata cylindrica ‘Red Baron’, whereas Echinacea purpurea ‘Golden Skipper’ did not achieve complete canopy closure. All other taxa showed 100% overwintering and stand retention; the values for E. purpurea ‘Golden Skipper’ were 67% and 11%. R. fulgida ‘Goldsturm’ and Miscanthus sinensis ‘Silberspinne’ achieved the highest Flowering Effect, while M. sinensis ‘Silberspinne’ and Panicum virgatum ‘Shenandoah’ had the highest Structural Value. Ornamental Continuity was greatest in R. fulgida ‘Goldsturm’ and E. purpurea ‘Golden Skipper’, despite the poor persistence of the latter. Four clusters differentiated taxa according to canopy stability, flowering, persistent structure, and seasonal foliage effects. Within the studied perennial planting, functional stability and ornamental continuity arose from different trait combinations, suggesting complementary roles among the evaluated taxa.