The Christian description of I. 'Alberto Castillo' quoted by Cathy
is exactly as I have experienced growing it for several years (bulbs
originally from Jack Elliot). It is really a robust plant, easily
the best of the several forms of this genus I have. The stems are
tall, the foliage abundant and the long lasting, heavy substance
flowers a beautiful, clear white and large; it makes a spectacular
display for many weeks in late Winter here in N. California (in a
pot). It will also open pollinate with ease.
I have always kept the pots slightly damp during the dormant season
(by allowing them to soak up some moisture from a saucer from time
to time) more out of ignorance than for any other reason save when I
saw these plants (the common species forms) growing in England, it
was obvious there was some residual moisture (from rain storms) all
Summer. They also get weak feedings of a balanced fertilizer in
solution over their growing period.
Dave Karnstedt
near Santa Rosa, California