Spiderwort us a clump-forming upright perennial. IT blooms with one-inch flowers that have three petals and come in either white, pink, blue, or violet. Spiderworts typically grow in moist, well-drained acidic soils. They do best in partial shade but will do equally well in sunny areas as long as the soil is kept moist. They reach a mature height of 6 to 12 inches.