To learn what hardiness zone you’re in, enter your zip code below. (Our thanks to the National Arbor Day Foundation!)

These zones are based on average minimum low temperatures which are a crucial factor in determining what plants can survive in any given area.

The range of zones we recommend for each of our bulbs can be found at the end of its description as well as in our comparison charts. We tend to be conservative with these in order to help assure your success.

The letter “a” in our recommendations refers to the cooler, northern half of each zone, while “b” refers to the warmer, southern half.

“W” and “S” in our recommendations refer to the West Coast and South/Southwest. Milder summers on the West Coast allow some bulbs to thrive there in zones which in the South/Southwest -- where summers are hotter -- they wouldn't survive.

Please note that the Arbor Day zones are similar but not identical to the standard USDA hardiness zones. The Arbor Day zones are based on more recent temperatures, and seem to better reflect the reality of our globally warming planet.