Hi Migsly.
Most waterlilies will bloom better in deeper water. My theory is that when the water gets very shallow the plant feels threatened by drought and it will turn from blooming to make seeds to making little hard tuber like rhizomes under the main plants. These hard little nubs can survive drought better than a fat soft rhizome with leaves. The fat rhizome dries up and dies but the hard little nubs survive until the water returns. Not only does the waterlily "think" "hey my water is drying up so why use energy making seeds that will just dry out and die and I need to make survival tubers" but the survival tubers make dormancy hormones that turn off flowering and since the flowering crowns can't grow fast enough to out-run the hormones because of the stress from drought, the hormones catch up with the crowns and they quit blooming like fall is approaching.
Varieties with Mexicana in their heritage are less prone to this in general but certain varieties are better than others. Clyde Ikins is one of the best waterlilies there is and by my guess and limited experience with shallow water I believe that it would be one of the best that you can have in your situation. Many old varieties with predominantly European-Odorata heritage are much more susceptible to this I believe. Any hardy waterlily that produces a lot of dormant tuber-rhizomes will stop blooming unless they are fertilized well enough and have a big enough pot or jump the pot. The combination of small pot, low fertility, shallow water and being an older variety that makes to many dormant tuber-rhizomes, and isn't a great bloomer to begin with, is the perfect recipe for having no blooms.
Since your water is shallow I assume that you pond is also not very big.This means that you want a compact plant. Shallow water promotes compactness. Instead of planting in a very small pot to keep your waterlilies small use a bigger wide shallow pot and put them in shallow water, 6-10 in. above the soil, and do leaf pruning to keep it in bounds. Don't fertilize too much, just enough to keep the leaves green and growing. Avoid old varieties that don't bloom well like Gonnerre and any varieties that don't bloom well late in the season because they are heavy tuberoid producers and a lot of trouble and disappointment. Most whites are poor late bloomers because they are close to the white species and don't have a lot of breeding behind them.
Another big problem is that you live in Florida. Very few hardies bloom well in the hot south by mid summer. Especially if if you have the situation that I describe above. Variety is EVERYTHING for you. By all means get yourself a Mankala Ubol waterlily. Also I hear that Colorado blooms well in the south. Just make sure that you fertilize it and give it a good size pot like I describe. They are both orange pinks and Clyde is orange yellow and they all have Mexicana in them. Laydekery Fulgens is a good blooming red that does good in the hot south I hear. All of these plants are medium to medium small.I have a new hot red-pink hardy X tropical that Rich Sacher has been testing in New Orleans and he says that is a fantastic hardy waterlily of its color for the south. It has dark marbled leaves and never stops blooming and never burns. Also it opens before 6 o'clock in the morning. It should come to market in the next year or so.
I hope this helps.
Mike.
