Department of Horticultural Science Part 1 -- General Aspects
The Amaryllis (Hippeastrum) is a true bulb that originated in
the tropical areas of South America. Thus, it is a tender bulb.
It performs best when grown under warm (70 to 75 oF)
temperatures for 9 to 10 months to promote flowering and
vegetative growth, followed by 2 to 3 months of either cool (55
oF) dry storage or cool (55 oF) growing conditions. The use of
one of the latter conditions is required to promote reflowering
of the bulb. Most marketed bulbs sold are greater than 8 inches
(20 cm) in circumference, and are either Dutch, Israeli, or
South African-grown. They produce 2 to 6 flowers per floral
stalk, with the average being 4. Very large bulbs normally
produce 2 flower stalks. Flower colors are red, white, pink,
orange, salmon, and bicolored (mostly whites with pink or red
flushes). Plant heights range from 18 to 36 inches depending on
the cultivar, the country in which the bulb was produced, and
home forcing conditions. Part 2--Indoor Gro