Rauhia multiflora cultural suggestions requested

Rauhias can be considered to be like Eucharis in that they are
decidedly intolerant of cold, even when dormant. They will happily
"endure" 5-6 months completely dry, crammed in a small pot (as you
know) and I don't have empirical data but I would not want to expose
them to temps below about 50*F even when they are dormant. It is one
of the few bulbs I keep protected year round in a heated greenhouse-
in Southern California. It seems the warm and dry together promote the
"roasting" needed to induce flowering in early spring.

Clean your bulb as well as you can and let it sit out to air dry for
at least two weeks. When you pot it up, water it once and not again
until you see evidence of growth. The top of the bulb should be barely
covered, though slightly exposed or buried a little deeper are ok too.
My rauhias grow well in about 70% pumice, 20% silica sand #20 and 10%
organic of your choice. The bulb needs to reach 4" or 5" diam. before
it will flower.

R. multiflora should make a good window sill plant as you note. It can
get big: the type collection by Werner Rauh had bulbs about 8" diam.
(!) and planted out in Hawai'i at Koko Crater the leaves are about one
foot wide. Not so easy in a pot.

Good luck!

Dylan

On 2/7/07, Boyce Tankersley <btankers@chicagobotanic.org> wrote:

Hi All:

I purchased a Rauhia multiflora during the 2000 IBS meeting in Chicago
and have been growing it on my west facing window in my office ever
since. The bulb has increased in size and now produces 2 leaves (versus
a single leaf when I obtained it). The bulb has also pointed out that I
planted it too high by gradually pulling itself down in the potting mix.
To say it pulled itself down is a poor attempt to describe the
relocation of the bulb storage tissues downwards over a couple of years.

The window is older, not well insulated and the cold air cascades past
the pot and over the window sill. Outdoor temps in the negative F range
and office temps overnight probably around upper 30's or lower 40's.

Both leaves developed water soaked tissue along the mid-vein and went
soft. I stopped watering and they eventually dried up.

The plant had been in the same 4.5" pot since 2000 so I decided it was
time to transplant and provide for new soil. 2 parts sand to 1 part
coarse bark mulch. Most roots were rotted; the 4 roots that remained
fleshy showed signs of browning at the tips.

Should I drench the new soil with a fungicide drench? Should I with-hold
water until new growth begins? Should I water immediately so the
remaining roots don't desiccate?

Many thanks,

Boyce Tankersley
Director of Living Plant Documentation
Chicago Botanic Garden
1000 Lake Cook Road
Glencoe, IL 60022
Tel: 847-835-6841
Fax: 847-835-1635
Email: btankers@chicagobotanic.org

Definitely in USDA climate zone 5 - despite efforts by some to
reclassify the region to a warmer zone. Second week of high temperatures
hovering around 0 degrees F. Night time temperatures have been brutal,
close to minus 20 F was the coldest.

Anticipate damage on woody plants due to an unusually warm weather (6
weeks) in late December through much of January. A number of geophytes
also were encouraged to begin growth too early but hopefully the inch of
snow we have on the ground will provide enough insulation to keep the
foliage from being disfigured.

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