Bea, in the Southern areas of the USA, traditionally 9a, they can be grown outside year round. They are often referred to as the Southern's Tulip, since they can be enjoyed as spring color in the manner that colder areas enjoy tulips and other spring bulbs that need a chilling during dormancy. The flowers on my outdoor Amaryllis last as long as they would as indoor potted bulbs. In my case (9a), the height of blooming is in April with a few early ones in March and a few late ones into mid May. In this forum, some gardeners are able to grow Amaryllis bulbs in the ground in zone 8b. It can be a matter of experimentation to find a sheltered microclimate, with some protection if a frost is expected. The foliage can freeze, but you need to keep the bulb from freezing. The enemy is as much moisture as it is cold. So the amount of winter moisture and soil drainage can also be a factor as to success in your zone.
