ISG Hardy waterlilies group

What are and what does ISG water lily mean

An ISG (Intersubgeneric) water lily is a water lily that has been created by mixing together two different sub genera and water lily, what does this mean? Which were created by mixing two different types of water lilies, it may be that they were created by mixing a rustic water lily with a tropical water lily, but it could also be that they were created by mixing different kinds of tropical water lilies, because if like rustic water lilies there it is only one genus, like tropical water lilies there are different genera and therefore the classic tropical water lilies the Australian tropical water lilies tropical nocturnal water lilies and others, so if I mix a rustic plant with a tropical plant I will have an ISG which can have rusticity characteristics of the mother water lily and therefore of the rustic water lily, do not suffer from the cold, whereas if I create a water lily by putting together a classic tropical water lily with a tropical Australian water lily, both being tropical water lilies, obviously I will obtain an ISG which will still be tropical.

ISG does not just mean a hardy water lily that has been created by mixing hardy with tropical but can also mean a tropical water lily that has been created by mixing two different genera of tropical water lilies, so not all ISG water lilies are hardy varieties.

It is therefore a good idea to specify whether the ISG water lily variety is of the rustic or tropical type, even if at the moment the ISG water lilies on the market in Europe are all rustic.

We are therefore talking about rustic ISG water lilies, which are nymphs created by mixing rustic water lilies with tropical water lilies. From this union, water lilies emerge which have the rustic characteristics of rustic water lilies and characteristics such as colour, shape and scent of tropical water lilies. They are nymphs which they can easily survive outside even in places where it freezes and have characteristics of tropical water lilies. For years they have been trying to create a water lily with the color blue or similar to blue, a color that belongs and belonged only to tropical water lilies, with this technique they managed to create water lilies that are close to the light blue/blue/purple color, but which can remain outside even in winter in cold places without problems.

There are different varieties of this type of water lily, at the moment they have higher costs than rustic water lilies or tropical water lilies because they have only recently been on the market.

ISG Hardy waterlilies group

How to grow this type of water lilies?

ISG water lilies are grown simply like any rustic water lily, I purchase the rhizome, prepare a pot of suitable size with heavy, clayey soil, and insert the rhizome of the water lily, compacting the soil so that the rhizome does not come out of the pot, I insert it inside of the tub or pond and place it on the bottom.

They are water lilies that can be positioned at depths of 30-50 cm. They can also be inserted into deeper waters but they struggle more to grow and produce flowers. Having tropical blood, they begin to grow and develop later than the rustic ones.

This type of water lilies need more nutrients than normal hardy water lilies, so good fertilization with Pondtabbs is strongly recommended and gives fantastic results on the amount of flowers produced and healthy plant growth.

ISG water lilies are not like the classic rustic ones that I can leave there for years even without dividing them, because if rustic water lilies can survive even in precarious conditions, ISG water lilies could die if they are not divided often (at least every two or three years).

The mother plant that grows the first year may not survive the following year, so it is a good idea for these plants to produce young from which new plants will develop for the following year. These small plants, if fertilized correctly and transplanted, develop very rapidly, and within a month I will have a beautiful flowering plant from a tiny rhizome.

To grow at their best, these plants need prolonged and direct sun exposure.

There are several hybridizers who have created and are creating these new types of water lilies, they exist with solid colors and with shaded colors, ranging from blue to white from white to pink and other colors, some that have classic green leaves some that have speckled variegated leaves, some that have white/pink or white/purple variegated flowers.

Most of these water lilies are scented, with a fragrance similar to tropical water lilies, and are very floriferous, being rustic varieties it is not necessary to remove them in winter, but it is better at the beginning of spring to take out the container where we have placed these plants, clean them, divide them, and rather make more vases which, if placed next to each other, obviously produce many more flowers.

Hardy ISG on sale

In our online catalog you can find some of the varieties of ISG water lilies from our collection for sale, below is the complete list, if you are interested in some varieties not yet on the site contact us to check any availability:

Alain Henaux

Amethyst Crystal


Antique Atmosphere


Bangkok Pink Panther

Bangkok Purple




Detective Erika

Fay Mc Donald

Garry Wagner

Gilles Chaygneaud

Hardy x Minuta

HXT orange unnamed



Light Blue


Mit Maitri

Nice Pattaya

Painted Star

Pink Kunzite

Pink Pink

Pink Silk

Pink Spot

Pink Tourmaline

Prae Ampon

Purple Cup

Purple Fantasy

Purple Lucent

Purple Queen

Purple Ribbonbow

Purple Silk

Purple Silver

Purple Star

Purple Zebra

Rep 5 Colors


Saroj Rate

Siam Pink 2

Siam Purple

Siam Purple 2



Sumanee Guna Kasem

Thai Delight


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