In the AVSA African Violet Magazine from July/August 2010 Sue Haffner's QUESTION BOX answers a reader's question about "Forsyth Pots" (or "Forsyth Gardens"). She had never heard of it and had to do a little research, describing it as "an old fashioned method of rooting cuttings of all sorts of plants" using a clay pot (with the hole plugged) filled with water and placed in the center of a larger pot filled with vermiculite.
The leaf or other plant cuttings are placed around the rim.
The outer pot could be plastic, but the center pot must be clay so that the water soaks through to the rooting leaves. I had to make plant stake markers to identify my leaves as nothing would stick to the damp clay pot.
Rob's Combustible Pigeon, Storybook Princess and Kandy Kitchen.
This PDF file from the University of Minnesota Extension Service describes the process more fully.
They note: * Plants that are somewhat difficult to root also have a better chance in a forsythe pot.
For African Violet leaves they suggest you:
"...poke the petiole into the vermiculite so there is contact between the underside of the leaf blade and the moist vermiculite. New plantlets will form at the base of the leaf blade."
It is not necessary that you "poke" the leaf all the way down so the the bottom touches the vermiculite as pictured on page 18 of the file. IMHO.
*Nobody seems to know who Forsythe was . . . ?
Update* This method may have been invented by a Mr. Forsyth as described in The Book of the Garden from 1853. That would make it an idea that's been around a while!
UPDATE September 17, 2012
Fuzzy mold growing on the outer clay pot drove home why clay pot use is widely discontinued!
Wiped it down with handi-wipe. ASAP! Will consider moving it farther away from plants if mold returns too soon.
Leaves are surprisingly still firm, although one seems to be "birth marking". I thought it was going mushy, but the discolored sections on the leaf seem firm.
- I wonder if straight vermiculite causes it?
- Constant moist conditions of the method?UPDATE October 15, 2012: ENDED EXPERIMENT.