What makes Amaryllis hybrids bloom?

Jane McGary janemcgary@earthlink.net
Tue, 25 Aug 2009 12:13:45 PDT
Michael Mace wrote:
>This isn't much evidence to go on, but my preliminary guess is that
>Amaryllis blooms in California are triggered by high rainfall in the
>previous one (or two) winters.

This is true of bulbous plants in various areas subject to extreme 
drought, including native bulbs in California (especially southern 
California) and in northern Chile. Another amaryllid that can be 
adduced as an example is Rhodophiala bagnoldii, the common species of 
northern Chile. After an El Nino rainfall year, I saw vast colonies 
of it in flower there, but after a series of dry years the only ones 
in flower were in a plantation of young olive trees that were being 

The last time I went to Chile we had hoped for another El Nino 
flowering, but the weather pattern that seemed to be forming when we 
made our plans (too early!) fizzled out, and flowering was poor 
except in the coastal areas of the "fog desert." The next time I head 
for the Atacama, I'll be sure not to buy any plane tickets until I 
know it's been raining.

Jane McGary
Northwestern Oregon, USA

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