April 28, 2020

If you ask people about pond plants chances are that the first thing they’ll mention are waterlily flowers.

There is just something about these gorgeous flowers that is romantic, breathtaking, almost mystical, those beautiful blooms in divine colours arising from the unseen depths of a pond.

Waterlilies, like many pond plants, are very easy to grow but there is a difference between growing them and getting good results. Here’s a quick look at what you need to know about these flowering gems of the water garden world.

A background on waterlilies

All of the true waterlilies belong to the plant genus Nymphaea. The mystique of waterlilies has existed almost for time immemorial with even the ancient Egyptians all but worshipping them. Even their true name, Nymphaea, hints at this as it is derived from the beautiful and playful water nymphs found in Latin and Greek myths.

An overview

Waterlilies flower generally through the warmer months but this will depend on the region and the varieties you are growing. The amount of sunlight they require varies by group but all require good direct, not filtered, sun to flower.
Most flower during the daylight hours but there are some night-bloomers. Virtually all waterlily flowers are perfumed and this ranges from delicate to delightful depending on the variety.

Waterlilies like good quality, clean water so are best in a pond or water feature where a pump is circulating and filtering water. They do not however like rapidly moving water or water splashing onto their leaves so plant them away from fountains or cascades.

Waterlilies are generally put into a pond in a pot. This can be lifted in winter, while the plant is dormant, to perform any maintenance or repotting (see below).
They do like to fed well but only use specialised fertiliser pellets or tablets that are designed for aquatic plants. Feed during the growing and flowering season

Waterlilies like to have their roots in the cool depths while their leaves are in the sun. Most will need to be at least 20cm, preferably 30, below the waters surface. If you only have a shallow pond you can help keep them cooler by adding lots of pebbles around and on the pot.

There are two main groups of waterlilies:

Hardy

• As the name implies these are the tough waterlilies that will grow through even freezing weather provided their roots does not freeze.
• From a technical perspective they grow from vertical running rhizomes.
• The best way to tell them apart from tropicals is that most often their flowers float on or stand a little above the water rather than being held on tall stems.
• Flowers range from white to yellow including creams to pinks, reds and crimsons. Some are colour-changers, slowly shifting hues as they open and age. The flowers can be as large as 30-cm across. And note that there are no purples or blues, that’s another way to tell them from the tropicals.
• Leaves can be quite large, up to 30cm across and are generally a deep, glossy green but can start a darker colour and may be splashed with rusty brown markings.
• Flowering time is generally spring through until early autumn and they need at least 4-hours direct sun a day to flower. Hot weather can cause some hardy varieties to stop flowering and their flowers can become scorched.

Tropical

• A slightly deceptive name as some varieties can be grown in cooler climates provided the water does not freeze however they will do best in warmer zones.
• Their roots are a more upright, clustering tuber or corm.
• Flower colour range is vast – reds and pinks, yellows, whites and luxuriant purples and blues. The flowers will be held on stems that are generally around 30cm tall and often have multiple flowers on the one plant.
• Leaves are not smoothly rounded like the hardy forms. They are often scalloped or even toothed on the edges. The leaves also tend to have a wider spread so they do need more growing space than the hardies. Many have strong leaf markings in deep mahogany shades.
• Flowering is from summer through until mid to late autumn or early winter needing 6-hours sun a day. In warmer regions they will flower for much longer with some spot flowering all year.

Repotting a waterlily

Repotting is quite simple and will generally need to be done every couple of years.

• Lift the plant while its dormant in winter.
• Trim off any dead leaves or flowers.
• Gently remove from pot and rinse off the old mix saving any pebbles.
• Use a sharp knife or pruners to remove any dead sections of roots and rhizome or corm.
• Line pot with newspaper a couple of sheets thick.
• Reposition in pot right way up and gently fill with a garden mix soil or specialised water garden potting mix. Regular potting mix breaks down to quickly. Add fertiliser tablets to the mix.
• Water thoroughly to rinse any silt through.
• Add a layer of course sand, such as washed river sand, to the top and then cover this with a layer of pebbles. This stops soil from escaping.
• Water again very thoroughly before carefully returning to the pond.

Native waterlilies

There are a number of absolutely beautiful Australian native waterlilies. These can be occasionally found through specialist growers and are worth tracking down. Their flowers tend to be much fuller and more lotus-like than typical imported species.

Many people mistake the Egyptian blue (Nymphaea caerulea) as a native as it has naturalised in many warmer regions of the country. Unlike the softer looking native species it has very pointy petals.

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