Growing from Seed-Floatation

Mary Sue Ittner
Wed, 20 Nov 2002 20:42:18 PST
Dear Lauw,

Since Lee Poulsen hasn't responded, here is what I saved from his excellent explanation of how he is successful with the floatation method along with comments from others on this list about floatation that I found interesting enough to save from the past discussion on the IBS forum. I hope you all don't mind my posting to this group.

Mary Sue

"Just wanted to put my two cents' worth in as well. (Okay, maybe 4 or
5 cents' worth...) The following steps are the accumulated result of
various trials and effort since I started using this technique.

I use those clear plastic party drink cups that have very wide mouths
and are about 3 inches tall. I write the name of the species on the
outside with a black marker, then I fill them with cool tap water. I
use tap water all the time now. I tried using distilled water several
times with older seed that I thought needed extra special care as
well as putting a few seeds in ordinary tap water, and the seeds in
the distilled water developed fungus/mold amazingly fast compared to
the tap water ones.  I now think this was due to the fact that there
is still a residual amount of chlorination in the tap water that
acted as a natural fungicide.

After dropping all the seeds onto the surface of the water so that
they float due to surface tension, I place the cup with seeds in one
of those plastic trays used to hold six-packs and cover it with one
of those clear plastic "mini-greenhouse" lids made to the same size
as those trays. Then I place the tray under fluorescent lights (with
my other indoor fluorescent light growing items), or if it is a
(mediterranean-climate) fall germinating species, I place it outside
where direct sun won't hit it and put a weight on the lid so it won't
blow away.

Once they have germinated and a green leaf has grown to a sufficient
height (about a cm in length or longer), I pot them into small 4-inch
pots using a medium made of 50% seed-starting mix and 50% cactus mix.
I fill the potlets with the medium up to where I want the bottom of
the roots to reach, tamp it down firmly, then take a small amount of
soil and make a little "ledge" of soil the depth of the roots. I
place 3 or 4 seedlings against this "ledge" where they stick, then I
place another small amount of soil against the seedlings' roots
forming another ledge, repeating until the potlet is filled and I
have several rows of seedlings all at the proper level. Then I drench
the pot from below by placing it in a large bowl or bucket and
filling the bowl or bucket with water up to just below the rim of the
little pot(s). Sometimes lately I mist the seedlings from above to
rinse off any soil sticking to the leaves and also to settle them
into the soil a little better.

Once they're drenched I take them out of the bowl and pour a small
amount of liquid fungicide on them. Next, and I now think this is a
key step to the method, I place them back in the trays and cover them
with the plastic lid and place them back in the same location they
were in while germinating. I leave them there for a week or two (or
longer) until at least another new leaf has grown in and a third
starts to appear. Then I place them outside in a mostly shady humid
location until they seem to be growing normally.

Ever since I started letting them recuperate back in their
"mini-greenhouse"  atmosphere, I haven't lost any to transplant
shock. I did this not too long ago with Pamianthe peruviana seed and
all the seed germinated and all of them survived the transplant
shock. (I lost almost all of two previous attempts at trying to start
this species.) One seed, that somehow slipped out of the plastic
drink cup onto a little pot of soil growing some other species,
germinated and grew under the same conditions but in soil the entire
time. It not only germinated much later (about two weeks after the
floating seed), it still hasn't caught up with the ones started by
floating that are growing right next to it. They have about 4 long
leaves each, while it still has only two much shorter ones. I have
also found that, at least using tap water, and especially for old
seeds with low germination percentage, if any seed is even barely
alive, it will usually manage to germinate and eventually grow a root
and a leaf long enough that I feel confident it will survive. (This
is often the case for me for seeds from Chiltern, such as Hippeastrum
seeds.) As Dell says, dead seeds usually mold very quickly. However,
it seems that old, barely alive seed has greater difficulty
germinating and surviving in soil without getting attacked by some
kind of microbe first than it does in pure water.

But that's just been my experience. I'm sold on this method as you
can probably tell."
--Lee Poulsen
Pasadena area, California, USDA Zone 9-10

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