How Do You Tell The Difference

Tropical and Hardy Waterlilies?


By Kit Knotts
Click images to enlarge

There are two main types of waterlilies that we can select for our ponds, tropicals and hardies. For details about how they are grouped by the scientists see our Waterlily Family Tree but, for most of our purposes, a description of their characteristics is enough.

The main thing that differentiates them for the grower is COLD! Tropical waterlilies don't like it and hardies tolerate it. Though all will go dormant in cold conditions, the rootstock of many hardies can survive in water just short of freezing solid. Where icing over is a threat, the tubers of tropicals must be removed from the pond and stored in moist cool to warm conditions to come back in future years. In warm climates they can remain in the pond.

This does not mean that hardies won't grow well in the south and tropicals won't grow well in the north. They will! Popular varieties of both are very tolerant of wide variability in temperatures and conditions. It is more a matter of style that should aid you in your selections.

Tropical Day Bloomers

Flowers - Colors include white, all shades of pink, yellow, autumn, blue, purple and undertones of green. All stand above the water and shapes are usually starry but some varieties are more cupped.


Hardies (All day bloomers)

Flowers - Colors include white, all shades of pink, yellow and changeable autumn. Many, though not all, float on the surface of the water and many are cup-shaped with some starry.

To see many different waterlilies - Cultivar Galleries


Growth Habit - Tropicals grow from a single central crown. All leaves and flowers radiate from this point and growth is vertical.



Growth Habit - Hardies grow horizontally from and along a fleshy rhizomatous rootstock. "Eyes" at points along the rhizome produce new crowns.


Pads - Tropical pads are usually somewhat thin with edges slightly scalloped or toothy. They can be plain green, flecked, mottled or whorled with maroon or bronze.



Pads - Hardy pads are rather thick and leathery with smooth edges. Most are plain green though many are lightly mottled with maroon when young. The exception is 'Arc-en-ciel' which is green, pink and maroon.


Propagation - From tuber and division for exact duplication, from seed for variation. In some varieties known as "viviparous", from new plants produced on the leaves.



Propagation - From division for exact duplication, from seed for variation.

We also include the characteristics of tropical night blooming lilies since they are a little different from day bloomers and we include N. mexicana, classified as a hardy but quite different from the rest of them! We don't recommend growing it because it is fairly undistinguished and can be invasive but it is a VERY important parent of many of our best hardy cultivars.

Tropical Night Bloomers

Flowers - Colors are limited to white, all shades of pink and nearly red. All stand above the water.


N. mexicana (hardy day bloomer)

Flowers - Yellow opening only in the afternoon. N. mexicana 'Cape Canaveral' has larger flowers.

Growth Habit - Night bloomers grow from a single central crown like day bloomers but multiply easily. Though multiple crowns can be desirable in large pots, too many "pups" will prevent the main crowns from attaining good size and bloom.



Growth Habit - N. mexicana grows from a central crown but spreads by runners which make new plants along them. Junctions in these runners can have little "bunches of bananas" that can also make new plants.


 Pads - Night bloomer pads have very toothy edges and often show more venation than day bloomers. They can be green, but are more often bronze-green to deep mahogany.



Pads - N. mexicana pads are rather thin with wavy edges. They are lightly splotched with maroon.


Propagation - From tuber and division for exact duplication, from seed for variation.. Night bloomers often make short runners from large tubers and then make new plants.


Potting Waterlilies

Propagating Tropicals From Tuber

Growing & Propagating Hardies

Propagating Viviparous Tropicals

Repotting Overgrown Tropicals

Growing Waterlilies From Seed

Waterlily Family Tree

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