Marie,
Yes, we both are getting the same info from Primlarp. And she is probably the best source for this particular subject, too. Did you know that Richard Sacher wrote an article on Jongkolnee that was in the May/June 1998 Pond & Garden Magazine? (Vol 1, Number 1, page 92.) It is pretty informative. I got it in a pdf, I think from an archive on the Water Gardeners International web site. If you don't have it and can't find it, let me know, I can email you the file.
I kept both tubers in a pot sitting on a plastic milk crate, in one of my patio ponds. This put it about half-way to the surface. They sat there for several weeks before showing signs of growth. One tuber started sprouting fairly well, the other just a single little pad. I abandon my idea of chain propagation on instinct. (Later, I learned that would likely have been a mistake.)
The onevigorousigorus tuber developed a number of small pads and sent out quite a few little roots. This one was planted in a small, 4 inch Lerio pot. In the bottom of that pot went about 1/3 cap full of Red Diamond prills. (Nutricote, the 270? day formula.) The pot was filled with a mix of bagged topsoil and my own sandy Florida soil. The tuber was pushed down in the soil mix so only the very tip with the pads was still exposed, the roots just under the soil. A thin layer of pure sand topped it off. No other fertilizer was added at that time.
The second tuber only developed a second pad after another week. I lost my nerve and potted it the same way, but in a one gallon squat pot. Both of these were set on a milk crate, so the top of the pots were probably 4 to 6 inches below the surface.
I am now convinced that if I'd kept the tubers much higher in the water when they were sitting in the empty pot, they would have started growing quite a bit sooner.
The first plant (4in pot,) started sending pads up to the surface fairly quickly. Once they were there and had spread a bit, I lowered that pot to the bottom and gave it part of the pond tab. The other one, (1gal pot,) just sat there, it even lost one of the pads. I kept watching it, even having to fan a growth ofalgae green algea from it that had begun covering what little growth there was.
A few days later, that one began to grow. When it's pads had spread about a foot, I lowered it to the bottom, giving it a full pond tab.
This was when Primlarp posted her comments about the need for full sun and plenty of room to spread. Rather than wait a couple of weeks to put in my 1st pair of "production ponds," I decided to throw up a kiddie pool and get that small pot with the Jongkolnee into it. When I did, I added a pair of pond tabs to the pot.
This brings us to the present. The "kiddie pool plant" is doing fine, the other is too, but will probably get it's own kiddie pool very soon. I think the 8ft diameter will be sufficient and the rather shallow depth, avg. about 15 inches, will help provide the warmth it needs.
So, what I think I've learned is that the very small tubers can as Richard says, be treated like seeds and planted with just the very tip at the surface of the soil. I will continue sprouting them first, in small tubs just under the surface in full sun.
Early growth like all tropicals can be helped by keeping the plant very shallow until 4 or more pads have reached the surface and have spread.
The Red Diamond (or Nutricote) can be put in early on, because it won't start releasing fertilizer for at least a month, and then only if the temp in the pot has reached about 70* or so.
When the pads do start their spread, a pond tab can be safely added. By the time it's gone, the prills should take over. Additional pond tabs can be added if/when needed. I'm still experimenting on using the Nutricote, by the way. So far, I've decided that the label amount of 3/4 cap full per gallon is too low for the plants I've used it on, so far.
As the Jongkolnee grows, I'll be posting more pictures.
Mike S.
Spring Hill, FL