SCARLET (Potenilla) CINQUEFOIL-All good gardeners love the Potentillas, and here's why: they cover themselves with scarlet flowers from early to late summer, while most other perennials bloom just a couple of weeks. What's more, potentillas are short (about 2 ft.) shrub-like relatives of roses, and if you look closely, you'll see that each brilliant 5-petaled flower looks just like a single wild rose. They're great additions to any perennial garden. Easy to grow from seed. Low maintenance. 100+ Seeds per order. potentilla thurberi. Perennial. Full sun / Part sun. Spring. Soil temp 70F+. SOW- Press 2/3 seeds per into soil, 16"apart. Keep moist. Germination 14-28 days. Thin to best seedling. Use scissors to cut out unwanted seedlings. Medium water. Height 24" x 16" Wide. Flowers are scarlet. Blooms early summer through fall. Light fertilizer every 30 days will increase blooms.