Jacob's ladder (Polemonium caeruleum), also commonly known as Greek valerian, is a woodland-type wildflower with attractive bell-shaped flowers in its signature deep blue color.
Jacob's ladder grows best in shady, moist conditions and requires only dappled sunlight, well-drained, and neutral soil, and cool summer temperatures.
Jacob's ladder earned its common name due to the rung-like arrangement of its pinnate, light green leaves. The species form and its various cultivars send up clusters of flowers atop long stems in mid to late spring.