Do you know the difference between an annual, biennial and perennial plant? If not, here's everything you need to know.

Biennial plants come back two years in a row, but not the same each time. Learn more about what this means, and 13 biennials to add to your garden.

Biennial plants typically are planted in spring and grow vegetatively during the first summer. These plants then go dormant in the fall and winter and grow vegetatively again the second spring, ...

Poison hemlock is native to Europe. It is a biennial plant, meaning that it has a two-year lifespan. Last summer, it went through vegetative growth and largely stayed out of sight as a basal rosette.