On Sat, 11 Feb 2006 Donna Anderson wrote
> I noticed that you have a Welwitschia mirabilis.
> I was able to get a few seeds for it.
> Did you start yours from seeds? Do you know what is the
> best way to do it?
Welwitschia are somewhat difficult to sprout and grow on because they are
very prone to damping off.
Once growing, they must never ever dry out completely. This is
counterintuitive because they live in such a dry and hostile environment,
but it is true. The late Seymour Linden, who grew them spectacularly from
seed he produced himself, told me this is one plant that can be watered
and fertilized every day of the year.
It was formerly thought they required deep pots for the tap root; thus,
many have been grown in drain pipes or PVC plastic pipes. Well, this is a
fable. It is true they don't transplant well when small, but the
dimensions of the pot are unimportant so long as the plant stays moist.
There is an online discussion list called cacti_etc devoted to cacti and
other succulents. It has an archive but it is not as easy to use as that
of the PBS. I extract things I find interesting in discussion groups and
keep them in text files. Following are some extracts from cacti_etc over
the years. I have edited them to remove E-mail addresses.
> Bowiea volubilis... This is another interesting
> plant I've been trying to find.
Seeds are readily available. I have grown them from seed purchased from
Silverhill Seeds and seed from my mother's plants. I suspect many others
on this list sell seeds and bulbs as well.
***
Thu, 13 Apr 1995
From: Myron Kimnach [Myron is former Director of the Huntington Botanical
Gardens.]
After reading all the comments about welwitschias I feel the urge to input.
Wild Welwitschia seed comes with a built-in destructive factor -- a fungus
that kills many seedlings within a week or two of germination (I'm not
sure if the black smut-fungus I've seen on the winged seeds in Namibia is
the same fungus that kills the seedlings). It's best to treat the seeds
with a fungicide before planting. The seed is apparently long-lived; Sam
Williams actually keeps them in his freezer for years.
In the early days of cultivating this species it was the custom to plant
one seed in a long drainage pipe stood on end. This was because of the
supposed long tap-root. According to Bornman's book on Welwitschia, the
tap root on mature plants may be 6 to 9 feet deep. However, a main source
of water are fogs and there are also many lateral roots near the surface
to absorb it.
The main advantage to growing the plant in a pipe is that the long leaves
can hang freely; I have never found any other reason to do so. I plant a
single seed in each three-inch pot so that if fungus attacks it will not
spread to adjoining plants. The seed is lightly covered with sand only.
Give plenty of water and never let the seedlings dry out. Leave the plants
in these small pots for about a year; then tranfer to a larger pot, taking
care not to disturb the fine, delicate roots.
Older welwitschias love water -- the main danger is letting them dry out,
as then the leaves turn a ghastly grey; usually they revive after a
thorough soaking. The plants should also be fertilized periodically.
The first plants to produce cones were at the botanical gardens at
Stellenbosch, S. Africa, and Montreal, and it took about 25 years for them
to appear. In the 1960's Leo Song at UCLA produced cones in 6 years by
subjecting the plants to extreme light, heat and fertilizer. If grown well
most plants should produce cones after ten years or so. Growth is
incredibly rapid if you plant the plants in a bed inside a greenhouse, as
in the Conservatory in the Huntington Desert Garden, where seed is now
regularly produced on both bedded and potted plants. Male and female cones
appear on separate plants and are easily cross-pollinated.
Welwitschias are not really succulents but are well-worth growing because
of their bizarre appearance and unique position in the plant kingdom; they
are gymnosperms, distantly related to conifers and cycads, producing cones
rather than flowers. The "trunk" never bacomes more than a foot or two
tall and it has the same two leaves over its lifespan of a thousand years
or so. I like to call it the Plant from Mars because, if plants grew on
Mars, I imagine they would look like Welwitschia.
--
Date: Tue, 11 Apr 1995
From: Chuck Hanson [Arid Lands Greenhouses]
We have grown quite a few Welwitschia seedling here with varying success.
If the seed is from cultivated plants, the germination is usually 100%.
Field collected seed varies from 50% to 0. No matter where the seed
originated, it should be treated with a fungicide, such as Thiram, before
sowing. The seed should be sown in a deep pot to prevent any more
disturbance to the tap root than is necessary. The tap root is touchy, but
repotting can be successfully accomplished with care. If the seed is not
fat, it is no good. Good seed will be ovoid in cross-section. In my
experience, most field collected seed is no good (no endosperm). Good seed
is apparently only rarely produced in habitat. Recruitment years are very
far apart for populations of this species.
--
Wed, 12 Apr 1995
From: LoWilla Wilson [LoWilla and her husband Lynn run a nursery in Broken
Arrow, Oklahoma.]
Lynn got his seed from the Huntington. He says freshest does matter. He
has very good germination and we always have seedlings. He told me he
really needs to draw pictures to describe what to do but I'm not good at
pictures so I'll try words but if they don't make sense Lynn will send a
diagram by snail mail (on request).
Make a depression in your soil mix and place the big end of the seed in
the depression, flat side toward the soil and at a slant. After the leave
come out VERY carefully place a piece of plastic underneath the seed case.
You must do this very gently or you'll cut the root. This cuts down the
chance of rotting.
Sam Williams taught him how to do this and gave him his first seed. It
worked and he's been growing with success ever since.
LoWilla
--
From Doug Ewing, Botany GReenhouse, UWashington, Seattle, Fri Sep 1 1995
Yes I do grow Welwitschia from seed in the greenhouse. I
have had no trouble getting germ. I put mine in small pots of general
greenhouse potting soil ( 66%peat 33%pumice) and put them in a warm
spot. I keep them moist until they are up and then never let them dry
out. I grow them like my average greenhouse plant, when they are starting
to dry a bit on the top of the pot, I soak them til the water comes out
the drain holes. I don't pot them in drain tile or worry about whether
they have a tap root or not ( the literature seems full of these
warnings, however). TThey are frequently fed with the same fertilizer as
the rest of the greenhouse plants get. I do supplement the light on them
by placing them 3 to 6 ft. away from 1000W HPS or MH lights on long
photoperiod (16 hrs). Using this method , I have gotten strobilation at
3.25 years from seed. Biggest problem for me is mealybug, which like to
hide under the leaves close to the meristem and feed. Light
supplementation might not be necessary in New Mexico. Good Luck.
--
From Root Gorelick, Fri Sep 13 1996
(In New Mexico at the time)
I ordered from SilverHill at about the same time you did and planted the
seeds in late April of this year. I only got 4 to germinate. I paid no
attention to the orientation of the seeds. I planted them in regular
potting soil in peat pots - so that I could later place them in PVC pipe
without disturbing the roots. All 4 grew their second set of leaves in
about six weeks. All 4 have survived and continue to grow slowly. I
should note that I am not yet growing them in full sun. So far they have
been about 25 cm from 2 cool-white and 2 warm-white flourescent tubes
that are on 24 hours a day. The peat pots are in a plastic rubber maid
container, and I water by pouring a few inches of water in the plastic
outer container twice a week.
Root Gorelick
--
Tue, 24 Sep 1996
I have several 2 to 3-inch seedlings of Welwitschia grown from
Silverhill Seeds, South Africa. They're in tall decapitated PET
plastic soda bottles under fluorescent lights. The soil is a 1:1 mix
of coarse sand and commercial potting soil. I water them nearly twice
a week, else the leaf ends die back.
The tap roots of the seedlings were at least 9 inches long before the
seedlings were 1 inch high.
I tried repotting a few at the 1-inch stage, to thin out the
seedlings, but lost about 50%, probably because the tap roots were
damaged during the repotting.
I've also tried separating a pair of plants with 1-foot leaves in the
same pot. The mass of fibrous roots were tough to separate, and all
leaves died back to the stem. However, both plants recovered, and
green leaves are growing back out from the stem.
Peter Wijeratne
--
Re: Welwitschia
Date: Mon, 03 Feb 97
From: Duke Benadom [Simi Valley, Los Angeles; former President of the
Cactus and Succulent Society of America]
In habitat, these seeds have very little chance of germinating. If the
conditions are not great, they won't grow. Having visited the Welwitschia
plain last October, I only observed one living seedling. The colorful
little beetles that are ubiquitous among the spans of welwitschias in
Namibia, seem to destroy the vast majority of seed, while the remaining
viable seed needs ample moisture and shelter to begin its life in an
unbelievably harsh environment.
Sam Williams from Charmichael, California, has offered some sound advice
on germinating this seed. Sam recommends that the seed be stored in a
freezer if being kept for more than a single season. Each seed should be
placed on a mounded portion of soil, then kept moist and covered with
plastic (or glass) until germination occurs. During the cotyledon stage,
care must be taken to keep the seed propped up above the moist soil;
otherwise the seed will quite often rot. Sam uses two toothpicks; one on
each side of the seed, with just a little of the mounded soil scraped
away to allow room for the toothpicks. Using his method, I now have a few
plants with leaves at least a half meter long. Transplanting the seedlings
at a juvenile stage has proven to be fatal; however, once the plants are
well established, they are easily transplanted. During the Northridge
earthquake in January of 1994 all of my welwitchias were violently
separated from their pots and from their soil. All were repotted within a
couple of days, and all survived. One of the plants had one of its leaves
severed at the body. The leaf has now regrown to about 40 cm in length.
Hopefully this information will have some use to those growing this
fascinating taxon.
Duke
***
Leo back again.
I know many of the people quoted above, and how they grow plants. What I
have noticed is that the people from arid climates who sprout their seeds
in a low-humidity area and do not use plastic wrap to enclose the seeds
have more success and less damping-off. The people who sprout in
greenhouses, where it is quite humid, have damping-off problems whether
they live in arid climates or not.
Leo Martin
Phoenix, Arizona, USA