Soapwort (used for making homemade soap) (Saponaria officinalis) 
Perennial and very cold hardy. Very old herb that has been used to make soap since before the time of Christ. Flowers, roots, stems and leaves are used to make liquid soap. Beautiful pink and white flowers. Approx. 15 seeds per pack. Sun to part shade. Likes moist soil. Barely cover seed and keep warm until germination. Two- to 3-feet tall in full flower. Will spread if given regular water, so you may want to plant in pots or inside a border.