Sanguisorba ‘Blackthorn’ (burnet ‘Blackthorn’)

Sanguisorba tenuifolium var. parviflora (white Japanese burnet)

Saponaria x lempergii ‘Max Frei’ (soapwort ‘Max Frei’)

Scilla mischtkenkoana (Tubergen squill)

Sesleria autumnalis (autumn moor grass)

Sesleria x ‘Greenlee Hybrid’ (Greenlee’s moor grass)

Solidago rugosa ‘Fireworks’ (rough goldenrod ‘Fireworks’)

Solidago x ‘Sugar Kisses’ (goldenrod ‘Sugar Kisses’)

Solidago ‘Wichita Mountains’ (goldenrod ‘Wichita Mountains’)

Sporobolus heterolepis (prairie dropseed)