Eugene, a light covering of sand (1-2 mm) is considerably different than a light proof covering of aluminum foil. You might find sand is quite translucent & provides stability to the small seeds. Karl On Jun 11, 2013 8:22 PM, "Eugene Zielinski" <eez55@earthlink.net> wrote: > David, and others. > I realize this is a bit off topic, but I want to share something I learned > about cactus seed germination, by experiment. The smaller globular cacti, > such as Mammillaria, Matucana, Lobivia, Trichocereus, etc. require LIGHT > for germination. Therefore, covering the seed with "a thin layer of sand" > will almost guarantee erratic germination. > I tried the following experiment. I took equal numbers of seed (about 20) > of several species. They were planted in two containers on the surface of > the growing medium. One container was left uncovered (well...covered with > clear plastic); the other was covered with aluminum foil. Both were placed > about 4 inches (10 cm) under regular fluorescent tubes which were on for > about 12 hours a day. Temperature was about 70 F (20 C). I had complete > germination within 2-3 weeks for the uncovered containers and no > germination in the covered containers (until I removed the aluminum foil > and exposed them to light). I did not try this with a lot of species, but > I am convinced of the light requirement. > I also tried this with some opuntia relatives. They did not respond to > light, but germinated erratically, and in low numbers. > Give the Sandoval method a try, but without the covering of sand. You may > be pleasantly surprised at how easily cactus seed germinates. > > Eugene Zielinski > Prescott Valley, AZ > USA > > > > [Original Message] > > From: David Ehrlich <idavide@sbcglobal.net> > > To: Pacific Bulb Society <pbs@lists.ibiblio.org> > > Date: 6/11/2013 6:31:29 PM > > Subject: [pbs] Sandoval at Fresno > > > > I attended Ernesto Sandoval’s lecture on South African bulbs Thursday > evening at > the Fresno Cactus and Succulent Society... > He demonstrated a technique for seed germination which I really liked, and > shall > be trying out in the future. He plants the seeds in a well-drained mix > (like > vermiculite, perlite, pumice, etc.), covers them with a thin layer of sand, > waters them and lets them drain thoroughly, then encloses the pots in a > zip-lock > baggie. When the seed germinate, he opens the zipper to allow air > circulation. > As they become sturdier, he removes them from the baggies; eventually he > plants > them out. His modus is to not stress the plants with too much change at a > time. Sounds sensible to me. > David Ehrlich > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > > > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >