1 oz. (Oenothera hookeri). Zones 3 - 7. Perennial. Evening primrose is a native of North America and was introduced into European botanical gardens in 1614 from Virginia. It is a biennial plant. In the wild seed germinates in the spring and in the first year the plant forms a rosette of leaves that is flat to the ground, later forming a stalk with alternate leaves. The plant flowers during its second year. Approximately 5,750 seeds.