Nymphaea Fidelity » Stimulate tubering in tropical water lilies with a drought

Stress stress stress

This method works by you guessed it stressing the plant. In native waters there are periods of drought and tropical water lilies respond by creating tubers. When the rain returns and water levels rise back to normal, the tubers sprout and grow new plants. Its a rather neat cycle!

You can trigger this response in your own pond or water garden. First we'll need to know several things. This is a process that takes some time and doing this will cause you to lose a good portion of your growing season (no blooms).

Lets begin

You'll need on average about two months of time and its recommended that you do this towards the end of your season as it just makes more sense. So to restate that--acquire a tropical water lily, enjoy its majestic blooms for the first half of your season or so but leave around two months for stressing via drought. It should begin to get cold by the time the stressing period is complete--this further stresses the plant.

• Weeks 1-2: Unpot tropical water lily from large pot and move to a small pot--do not fertilize. We highly recommend a pot with holes at the bottom but more important choose a pot that is smaller than a gallon. We have had amazing results with quart pots.
• Week 3: Move the tropical water lily which should be in a small pot closer to the surface of the water. If you had it at say 18 inches of depth, move to 9 inches. Note that that we measure depth from the water surface to the crown of the plant.
• Week 4: Move the tropical water lily even closer to the surface of the water. If before it was at 9 inches, now move it to 5 inches.

Midpoint checkup

You are about half way, you'll notice several things occurring. First you'll see a decline in plant size which means smaller and less number of blooms. This is normal. This is great as these are signs of stress. Next you'll see the foliage do something remarkable. They will begin to curl upwards and as you progress with this stressing period, the plant will hold the foliage out of the water similar to what lotus plants do.

• Week 5: Once again move the tropical water lily towards the surface of the water. It was 5 inches, now move it to 1 inch.
• Weeks 6-7: Keep the plant at this level. The plant should have stopped blooming and cold weather should be approaching.
• Week 8 or more: You will want to leave your tropical water lily plant until just before the first frost will occur.

In the video below we have a N. Midnight Serenade that volunteered to help you understand what a tropical water lily should look like during its final weeks of undergoing stress.

Stressing a tropical water lily with low water level from Utopia Aquatic on Vimeo.

Harvest for overwintering

It's now time to unpot the plant and gather the tubers. We recommend tossing them in a tropical aquarium as that is the best method for overwintering. They will sprout underwater foliage and when spring comes around you can set them in your water garden or pond at the appropriate time. As for the actual plant you have several options:

• Send it to a warmer climate. There are some places that tropical water lilies grow and bloom year round (that sounds like our location in Florida).
• Toss the plant--although not recommended.
• Grow the plant inside during the winter.

Let us review

Your tropical water lily is stressed through a small pot, lack of nutrients, simulated drought, and finally cooler water temperatures. It must occur over a period of time as tubers do not form overnight. Good luck!

Filed under: Cultivation, Tropical water lilies