Kerria
(Kerria japonica)

Kerria is available in both single- and double-flowering varieties,  but the double form clearly makes the superior plant. In mid-spring, the plant is clothed with a multitude of golden-yellow blooms about 11/2 inches across. The double flowers, sometimes called globe flowers, are densely petaled and baillike. The slightly arching branches remain bright green all winter long. Leaves are triangular, serrated, and 2 to 4 inches long, turning yellow before failing in autumn. Kerria is 4 to 6 feet tail at maturity.

Soil: Average
Light: Part shade; full sun in areas where it remains cool.
Zone: 4

Comments
Kerria tends to spawn suckers easily, losing its shrublike appearance. Keep pruned to shape.