This perennial features gray-green sword-shaped leaves and large yellow blooms that can measure up to 4 inches across. They can grow as tall as 4 feet and can feature four or more early spring-blooms on each stalk. Yellow flag could spread in a wetland area, but those grown in dry areas will likely be smaller and spread less. USDA Zones 4-9TOH Tip:
Check with a local garden center professional before planting this, as the plant may be considered invasive in some areas.