NOTE: some tubers produce rooted plants in three weeks; others may take three months. This is why it makes more sense NOT to plant the tubers into soil when they are still dormant…rather, sprout them in bags of water, and plant only those which have rooted plants on them. This saves time and space, and makes best use of the heated water bath.
Some sunlight should be available when the tubers begin to sprout and put out leaves. If some air is left in each bag, the bags will float near the surface, making it easier for them to get sunlight…and easier to check plant progress. Check each bag once a week to see if any tubers have enough plant growth with roots; if so, it is ready to be removed from the bag of water, and planted into fertilized soil.
Plant the sprouted tubers: Those tubers with small plants and roots attached are now planted, in fertilized soil, in a 4 inch pot. I leave most of the tuber exposed at a 45 degree angle above the soil line…only the growing points and roots need to be in the soil. This angle of the tuber encourages the small plants to develop short runners at the crown of the tuber, making it much easier to remove the plants later on, when the root system is well developed. At this point, water temperature of 75 degrees F. is sufficient for the newly potted tubers, although higher temperature will result in faster growth. If your tank of heated water has the room, these first potted tubers can be left in the warm water for a week or so, before moving to a pond which is 75 degrees or warmer.
NOTE: By planting the tuber with the small plants still attached, it greatly increases the growth of roots and leaves for all the attached young plants. Smaller plants, which may not have sufficient roots upon planting, will continue to develop while attached to the tuber, whereas they might not survive if they were removed prematurely along with the older, better rooted plants.
Remove the plants from the planted tuber: After 2 weeks or so, there will be an extensive root system in the 4 inch pot. Some roots should be coming out of the bottom of the pot. Remove the tuber from the pot, and rinse away ALL soil. Gently rock the mass of plants back and forth until they separate from the tuber. (The tuber can then go back into a zip lock bag of warm water, and it will sprout more plants in 3 to 4 weeks.)
There may be three to six rooted plants in the mass of growth which has been removed from the tuber. The root system for each plant should be teased apart UNDER WATER, to reduce friction and root breakage. A ball point pen is ideal for helping to separate the root systems under water. It helps to do this in a tub of pond water on a greenhouse bench. Separating the individual root systems is the easy part; now, the plants themselves need to be separated from each other with minimum loss of leaves.
Place the clump of plants on a wet, shaded surface, and begin to separate the leaves for each plant. Start with the plant with the smallest root system. The smaller plant has smaller and fewer leaves, and will be easier to untangle than a larger plant. Work your way up to the largest plants, last. Place each plant in a tub of pond water as soon as it is separated, so it does not dry out. A paper towel or piece of newspaper between each plant will keep them from entangling again. A plant with as few as 3-4 small leaves will usually be successful, as long as it has some good roots. The more and bigger the leaves, and the more roots a plant has, the faster that plant will grow.
Now plant each plant into a four inch pot of fertilized soil. I press the soil to one side of the pot, lower the root system toward the bottom, while leaning it against the “wall” of soil, then fill in the remaining void. This spreads out the roots nicely, in the center of the pot. Place in water at 75 degrees F. or higher, and check after two weeks to see if roots are coming out of the bottom of the pot. If so, it is time to transplant to a larger pot. Two to three weeks is the maximum time that most plants need to remain in the four inch pot before transplanting to a six inch pot…unless you are making tubers. In that case, leave the plant in the four inch pot, remove escaping roots weekly, and the plant will go dormant in 6-8 weeks, having formed a tuber.
Remember: although tubers must be sprouted in water temperatures between 85-90 degrees F., once the new rooted plants have formed on the tuber, and the tuber with its rooted plants is planted into a pot of fertilized soil, temperatures of 75 degrees F. or higher are sufficient to promote decent growth.
Sometimes an overlooked zip lock bag will be found with a tuber which has lots of plants, each with extensive root system. In this case, rather than planting them as a unit, as is usually done, one can remove the plants immediately, and tease the roots and plants apart…and plant each plant directly into its 4 inch pot.
Growing to saleable size: Once the four inch potted plant has been transplanted into a six inch pot of fertilized soil, it will take 3 to 4 weeks to reach a saleable size, with flower buds. Plants should NOT be left in the six inch pot longer than 4 weeks…or they may cramp and starve, and begin to go dormant.
Where space is not limited, instead of going from a 4 inch to six inch pot, the four inch potted lilies can be unpotted, and the root mass pushed into the soil/muck at the bottom of a pond or tank; space them two feet apart. They will grow nicely in the ample bottom soil, with no chance of premature dormancy. They will then be fairly easy to uproot for sales, with most their roots intact. Plants that have 4 to 5 good leaves, with most their root system attached, are going to be successful in shipping to the customer…as long as they replant immediately into fertilized soil, in water 75 degrees F or higher.
Other observations: When N. Betty Lou plants are small, in the 4 inch or 6 inch pots, their flowers will not be impressive! The flower color may be pale, and the leaf spread will be more spread out than will be seen on a mature plant. Once it has been in a 10 inch pot (or larger) of fertilized soil, the blooms will become darker in color, the stamens a very deep orange/pink, and the larger leaves will have shorter stems. At this stage, only five mature, newer leaves need to be left on the plant to insure blooms. This observation is true for almost all tropical lilies…they make far more leaves than they need to stay in bloom.
In a ten inch pot, N. Betty Lou can have a spread of 5 feet before some outer leaves turn yellow; but it can be kept to a spread of only 4 feet by removing the older, outer leaves, as long as 5 young leaves are left on the plant.
In a production situation, where it is desirable to minimize overcrowding, I would reduce each 6 inch potted plant to the youngest 4 leaves every week. Four inch potted lilies are allowed to keep any leaf that is not beginning to yellow.
The secret to producing enough plants for the beginning of the sales season is two fold: You must start the tubers into growth in 85-90 degree F water…and you must start the process early, by February 15th in the U.S…. about four months before your targeted date for sales. This is true not only for Betty Lou, but for any of the Aussie hybrids or species.
There has long been a myth in the industry that Australian water lilies are prone to go dormant when they are shipped. Not true! IF they have most their roots and leaves intact, and they are immediately replanted into fertilized soil, in a pond of warm water, they will not go dormant on the customer. I have shipped Aussies to Denver, Florida, and to West Virginia, with no problem.
Another myth is that Australian water lilies require deep water. They may tolerate deep water in Australia, but we grow a number of Aussies with only 5-6 inches of water over their pots, and they are just fine. There is one benefit to deeper water however: those Aussies that have large flowers and long stems seem to better resist falling over in rainstorms when the water is 18 inches to 24 inches over the soil level in the pot. (One of the benefits of Betty Lou is that it does not need the support of deeper water to keep its blooms erect.)
Finally, all of the cultural information above is applicable to any Australian native or hybrid water lily. The next Australian which ought to be feasible to bring to market is immutabilis, because it is relatively easy to raise from seed. To prevent premature sprouting of immutabilis seeds, I store them in barely damp peat moss at room temperature.
When I am ready to germinate any Aussie seed, I rinse off the peat in a coarse strainer, and place the seeds in zip lock bags of water, in a 90 degree heated tank. I plant the seeds into shallow trays of fertilized soil when I see at least 30-40% germination in the bags, which takes 3 to 4 weeks. I place about 25-30 germinated seeds on the surface of a 10 inch saucer of wet, fertilized soil, and then cover completely with ¼ inch of sand. Gently slip the saucer under water in a heated tank. Raise the saucer to within an inch of the surface. ( I prop them up on an empty pot.) Separate and replant the seedlings when most have a few floating leaves that are at least 1-2 inches in diameter, planting one seedling to each four inch pot of fertilized soil. In 2-3 weeks, they will need to go into larger pots.
Sometimes, after the seedlings have floating leaves, but are still too small to be transplanted, I like to push some crumbs of fertilizer tablets into the soil in between the seedlings, to encourage more growth. Sometimes, I invert the well rooted seedling tray, sprinkle some fertilizer on the root mass, and then return it to its tray. They will need to be transplanted within ten days or so after this supplemental feeding.
Rich Sacher, New Orleans LA, Oct 15, 2016