| Prickly-seeded Spinach Seeds (Spinacia oleracea). Jefferson sowed Prickly-seeded spinach in the Monticello vegetable garden in 1809 and 1812 for both a spring and fall crop. Mentioned as early as the 13th century in Germany, this smooth and triangular-leaved spinach is named for its thorny clusters of seed.... - Prickly-seeded Spinach Seeds (Spinacia oleracea). |