How to Grow Australian Waterlilies: Protocol by Rich Sacher– Pond Megastore

If you could kindly take a moment to select your state we can instantly
remove any listed invasive illegal plants in that state from view
Thank you!


How to Grow Australian Waterlilies: Protocol by Rich Sacher


(Please note: all the following protocols apply to any Aussie species, its hybrids, and its inter subgeneric hybrids! This protocol is especially designed for a commercial grower.)

Immutabilis x colorata  (N. Betty Lou) is not a difficult cross to make, and others have done so; my criteria for selecting my clone of this Australian hybrid were:

  • A much more compact size than other crosses with Australian natives.
  • A constant bloomer, once mature, until late in the season.
  • Easy to grow, easy to propagate, easy to over winter tubers.
  • Typical flower form for an Aussie, but with unusual orange/pink stamens.
  • Short, sturdy flower stems that resist falling over in wind and rain
  • Making tubers:  Transplant 2 or 3 small, rooted offshoots from a tuber into fertilized soil in a 4 inch pot; do not fertilize again; remove any roots that escape from the bottom of the pot, so the plant starves. Tubers will form in 6-8 weeks, and the plants will go dormant. Remove the tubers from the soil, rinse  clean, and store  in barely damp peat moss, in a zip lock bag, at room temperature. Tubers will be fine like this for up to a year…and maybe much longer. In Australia, many ponds are seasonal, and evaporate in the dry season. The tubers of the native lilies lie dormant in the mud, and sprout again when the pond refills with rain. Storing our tubers in damp peat moss MAY be duplicating the natural dormancy cycle for Aussie tubers. (Just a theory!)
  • Fertilized soil: My mix is one six inch pot of sandy loam, one handful of peat moss, and one full tablespoon of granular Azalea/Camellia fertilizer (13-8-15), mixed well.  I have also used 13-13-13 when that was more convenient. The peat moss adds acidity to the mix, and acts like a biological sponge to hold onto the dissolving fertilizer, so it will not dissipate too quickly. This mix can be used on the small, rooted plants when they are removed from the tuber and also at every stage of transplanting to larger pots.  I like to put  more fertilizer in the bottom of 10 inch pots when I am transplanting into them for our local sales. In this case, I  add a handful of peat moss to the bottom of the pot before sprinkling in two tablespoons of  fertilizer. I then put an inch of fertilized soil on top of the peat, then the unpotted six inch water lily, and fill in around the soil mass with more fertilized soil. (This is my protocol for all water lilies, tropical and hardy!)
  • Barely damp peat moss:  Peat moss is acidic and reduces the possibility of rot while the tuber is in storage…although sometimes, a superficial mold may occur. The peat moss should be damp, not wet. Pick up a hand full of peat moss, and squeeze it hard; if any water comes out, it is too wet. The peat should mostly hold together when you release your grip. If it falls completely apart, it is too dry.
  • Zip lock bags for tubers: Use high quality quart bags, and seal them tight. They only need enough peat moss in them to surround the tubers. I prefer not to put more than three tubers in a bag; only two tubers if large, or up to four tubers if they are small. Label each bag. Store indoors at normal room temperatures. I keep mine in my office. I roll up each bag like a burrito, to save room, and place into a tub or bin with a tight cover. PROTECT these bags from rodents when storing them.  Mice and rats LOVE to eat tubers. You have been warned!
  • Sprouting the tubers:  In early February, (or at least four months before your target date for first sales) the tubers should be washed completely free of peat moss, and placed two or three to a zip lock bag of clear water; If there are too many tubers in a bag, the new plants will be more difficult to separate once they have roots and leaves.  
  • These bags are floated in a tub of heated water in a greenhouse…an aquarium heater or two can be used to keep the temperature at 85 degrees F, or a bit higher.  If the tub is large enough to warrant it, a very small pump (30-40 gph)  can be placed in the tub to circulate the heated water…avoiding hot/cold spots.  Some hornwort can be placed in the heated tub to prevent green water, which would block sunlight to the developing plantlets.

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


Contact us


Just added to your cart:
Excl. postage 
My Bag
Just added to your wishlist:
Excl. postage 
My Wishlist