In the spring they begin growing again, then later flower and produce seeds. Parsley and fennel are examples of biennial herbs that need a cold period. Garlic, too, requires vernalization in order ...

Learn about the three main weed classifications—annual, biennial, and perennial—and how they impact garden management.

Garden expert Melinda Myers says, "These canterbury bells (Campanula medium) are often used in flower arrangements and can be ...