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  titanum update
From: Clark Riley drriley at mypcr.com> on 2001.09.04 at 15:01:20(7330)
A few years back, I had the great good fortune to be part of the
distribution of Dr. James R. Symon's Amorphophallus titanum seed. The
seed sprouted in good percentage and the plants have proven quite
reliable as house plants. I distributed the majority of those plants
to botanic gardens across the states but kept three for myself. My
experiences are for these plants grown in Baltimore Maryland, midway
between Washington, DC, and Philadelphia.

1. The individual leaf lasts about two years under these conditions.
The rest period between leaves is variable, but at least 3 months in
my experience, regardless of watering conditions. I have yet to
figure out if anything other than age triggers dormancy. I have the
plants growing side by side and they enter dormancy when they please

2. If I withhold water, it seems to prolong dormancy, but don't wait
too long. I have lost the main bud on the tubers this way. I have yet
to succeed with lateral buds, even when they were on a protuberance
from the side.

3. I repotted the tubers this year and placed the pots outdoors after
our weather was consistently hot. From previously reported
experiments on my younger seedlings, I can say that Amorphophallus
apparently hates even cool weather. From the time I started watering
until the growths emerged was about two months. They were about 3
feet/1 meter high after a month.

4. The length of the "trunk" of the leaf, the petiole, is quite
sensitive to the intensity of light the plant receives during the
elongation phase. Under the light of fluorescent bulbs, the leaf stem
can easily reach 10 feet on young plants. Petiole length is an issue
for me as I have been trying to grow the beasts in our basement where
I have only about 5 feet from bench to lights. Even if the tubs are
on the floor, I can only accommodate 7 feet. If growth begins in late
Summer, I can coax the stem sideways, where it will be confined for
its two years. Hence, I try to synchronize the beginning of growth
for late Spring or Early Summer. Once the compound leaf has unfurled,
the petiole will not elongate further and I have a stout 3 foot "palm
tree." The leaf will then reside close to the lights through the
Winter. I find that Amorphophallus titanum enjoys full sun, even full
Maryland noon sun.

5. The tubers continue to enlarge each year and are now 3 - 5 pounds.
Like many other aroids I have had the privilege of growing, the size
of the growth seems dependent on the container size. It's not just a
matter of potting on. The size seems to reach stasis if kept in a pot
less than about twice the tuber diameter.

Hopefully some of these observations are helpful to those who have
the privilege of obtaining these kings of the plant kingdom. Other
observations are eagerly sought. For those who have bloomed this
species, have you succeeded in setting seeds?

Clark Riley

From: Tony Avent tony at plantdel.com> on 2001.09.05 at 01:41:26(7336)

With regards to dormancy of A. titanum, we also have plants from Symon's
original seed collection. We have never had any problem forcing them into
a standard dormancy pattern in fall. By allowing them to remain outdoors
until temps reach around 35 degrees F., then bringing them indoors, they
will all go dormant within a couple of weeks. After nearly 10 years of
this routine, we have had perfect success. They usually re-emerge between
June and July. I hope this helps for those without a conservatory.


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