This perennial has a sturdy stem and grows to be about 6 inches to 8 inches tall. Clusters of flowers decorate its tip. Jacob's ladder blooms in spring and usually shows off half-inch light purple or blue blossoms. Less common types have pink, yellow or white flowers. Sow seeds in the spring or fall, and if you want to start seedlings indoors first, it will be about two months before they're ready to be transplanted into your garden. Jacob's ladder does best in partial shade. The ideal soil for this plant is rich, moist, cool, well-drained and has a pH of 5 to 8.