One thing I don't see mentioned in ANY of the replies here is that amaryllis are very heavy feeders and forcing them really stresses the bulbs for indoor bloom in winter. For this reason, see to it they are adequately watered while outside in the summer, and use "bulb booster" or bone meal to nourish the bulb (scratch it in around the bulb once planted and place a teaspoon in the planting hole to mix in before placing bulb. Get them out EARLY and make sure they are located where they get the MOST sun so take advantage of the heavy feeding they will do with the water and fertilizing. This WILL make a difference in whether your bulb blooms in subsequent seasons. I've been culturing them for 20+ years and this is the most important and best recommendation I can make. ALSO -- the rest period IS indeed an important element of the re-blooming cycle. Good luck to all; feel free to contact if you have questions!