What is a hardiness zone?
The US Department of Agriculture and the US National Arboretum have prepared a map representing winter hardiness for certain types of plant material. Most fall planting bulbs are considered hardy and will survive the most severe winters including, tulips, daffodils, narcissus, hyacinths, crocus, scilla, fritillaria, iris, snowdrops, muscari, eranthus and chinodoxa. However, if you do live in zones 1 through 4 or if you live in the mountains additional mulch to protect against severe freezing temperatures (20 degrees below zero) is recommended. For more details about your specific region please click on the link for the Zone Map.
