Hippeastrum is an evergreen bulb. With proper care it does NOT go
dormant. If you force it to go dormant, you risk sacraficing the
next season's flowers.

True Amaryllis is a deciduous bulb. It does go dormant. As with
all deciduous bulbs, however, if you remove the foliage while it is
still green you risk killing the bulb.

See my http://www.rossde.com/garden/garden_hippeastrum.html for
information on how to distinguish between Hippeastrum and
Amaryllis.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/