60 days. Known as Patience Dock, Spinach Dock, Garden Patience or Monk Rhubarb, this fast-growing vigorous herb is renowned for its uniquely tart, lemony flavor. Rich in vitamin C, Volare's large green, arrow-shaped leaves can be used in many of the same ways as spinach. Our staff unanimously preferred its flavor over Garden Sorrel. Foliage grows to 3-4' and will quickly regrow after harvest. Perennial in Zones 5-9.