Water lily - Nymphea

They call them water lilies

The water lily is one of the most widespread aquatic plants in cultivation; to the genus belong about 50 species, widespread in most of the northern hemisphere, some of which are native to Europe; in fact their success derives, in addition to the large flowers, from the fact that their presence can be found in most European watercourses, in the wild. There are also some hybrids, with particularly large flowers.
Nymphea is the most well-known aquatic plant due to its beautiful flowering and its great adaptability which leads it to be very common even in its spontaneous state.
Furthermore, it is a very simple vegetable to be cultivated provided that we choose a variety suitable in size to the depth of the reservoir and that we dedicate ourselves regularly to the division. The water lilies are floating aquatic plants, the whole plant develops completely submerged, and only a portion of the rhizomatous roots sinks into the ground at the bottom of calm streams, small lakes or rivers; the stems are as long as they are deep the water of the place where they develop, in fact they rise from the bottom to the surface, where the foliage develops at the water's surface; the nymphea stems are equipped with particular cavities that allow the floating, if extracted from the water they fall back on themselves, not having enough woody parts to support the plant even out of the water. The foliage begins its development completely submerged, rolled up on itself; while the stem that bears the leaves develops, these tend to grow larger; when they reach the surface they unroll on the surface of the water and float; the lower page of the water lily leaves is specially structured to float, while the upper page, covered with a thin layer of water repellent wax, performs the functions of breathing.
In spring and summer, large white, sometimes pink or slightly bluish flowers bloom among the leaves.

To cultivate a water lily plant it is necessary to have a small pond, let us remember that the botanical species produces some leaves, which can reach a diameter of about 25-30 cm; the entire plant can cover up to 120-140 cm of water with all its leaves. We lay them down simply by letting them float on water; the plant itself will produce the roots that will sink into the bottom of the pond; if we have a pond with a plastic bottom we can place our water lily in a basket for aquatic plants, in which we will place specific soil, and some stone, which will allow us to anchor the basket to the bottom of the water.The cultivation of water lilies is not difficult, in fact these plants tend to survive without the need for human intervention; they do not fear the cold and can survive even in areas with a very cold winter climate, as long as the water in the pond does not freeze completely; in this case we transfer our water lily in a sheltered place, in a large tank: we will reposition it in the spring.In waterways and lakes, water lilies are left to grow undisturbed; in the pond of the house they can instead become invasive; it would therefore be appropriate to periodically practice good pruning, thinning out the largest or most ruined leaves, to allow the development of new foliage.Water lilies are totally aquatic plants. To live well their root must be completely submerged. They prefer ponds or basins where the water is stagnant or with at most a very light current. There are more or less rustic and of any size.They are composed of an underground part, a tuberous rhizome, to be inserted directly on the clayey ground or in a basket with appropriate soil. From this stems the stems and leaves. The latter float on the surface. The upper page is generally dark green, the lower one tends to red-purple. The smallest have a diameter of about 8 cm, the largest, spread in the spontaneous state in the Amazon, can exceed 4 m.The flower stems are emitted from late spring to autumn, depending on the varieties. Each bears a single bud that opens when it reaches the surface of the water and lasts a few days, opening in the morning and closing in the evening. The corollas are available in a wide range of colors: white, soft pink, fuchsia pink, yellow, salmon, red. There are also blue varieties which, however, are not very rustic. Flowers are released for a long time and are fairly constant, with a short quiescence period in July. Once dried, they sink into the water and turn into fruits that, when ripe, come off and spend the winter at the bottom of the water basin. It is a lively herbaceous: it produces spring vegetation in autumn to enter dormancy in winter, when all the dry aerial part. They are important plants for the aquatic environment. Although they do not perform an oxygenating function, they act as a shelter for fish, tadpoles, frogs and toads. Shading and reducing the amount of nitrogen present in the area hinder the spread of algae.Exposure and positioning of water lilies

To grow and flower abundantly they must be placed in a sunny area, in full sun for at least 6 hours a day. Air currents should be avoided and the water should be as firm as possible. Every single specimen of medium size needs about 1m2 of surface. The depth of the water mirror must be commensurate with the size of the plant. Smaller ones also live well with roots about 25 cm deep. Most, however, need a container at least 40 cm deep.


The ideal time to proceed is the end of winter, from early March to April. In particularly temperate areas (Central-South or coastal areas) it is possible to do so even in autumn. For varieties of tropical origin it is instead imperative to work from May onwards.
Baskets composition and positioning
The ideal is to make use of special baskets for aquatic plants, to be placed on the bottom. They are very practical because they allow the subjects to be quickly extracted from the water to carry out periodic divisions, fertilization and ordinary maintenance. They are also essential to prevent plants from spreading independently.
They should be filled for 2/3 with clay garden soil (or a special compost for aquatic plants). We insert in each basket only one rhizome, positioning it obliquely and with the eye upwards, without this being covered by the earth. We must be particularly delicate with the roots, absolutely avoiding to break them or engrave them. We insert within each basket the prolonged release mineral fertilizer. On the market there are specially designed products: let's make sure there is an important supply of potassium and that the nitrogen is scarce. This will stimulate flowering and prevent the growth of algae. Moisten the substrate well and cover the surface with gravel or pebbles. In this way the minnows present in our water mirror will not move our work.
At this point we can insert the plants at the right depth.

Care of water lilies

Maintenance, for rustic water lilies, is really reduced. It is almost never necessary to extract them during the winter season. It can be essential only if our body of water is less than 30 cm deep (and therefore could freeze completely) or if we grow exotic specimens.
• In spring it is good to put one or two specific fertilizer tablets in each basket.
• In summer we check that the leaves are not too many. The ideal is that they cover at most 2/3 of the surface of the basin.
• In autumn we gradually eliminate all the yellowing leaves: in this way the water gets less dirty and the appearance of algae will not increase.
How to pick up exotic specimens
The varieties coming from the Tropics or from the Equator must be withdrawn because they do not bear temperatures below 10 ° C. We wait at least the end of October (or even November, in the Center-South).
Let's extract them from the pond and put them in a smaller container (a basin is fine too) to keep inside, in a slightly heated greenhouse: the temperatures must never fall below 10 ° C and the environment must be well lit. We can move them outside again around mid-March.

Reproduce the water lilies

The division of the rhizomes is practiced almost at the hobby level. Sowing is rather complicated and gives results in very long times. It is a method adopted solely by breeders to obtain new varieties.
In normal conditions it should be done every 3-4 years. It is necessary when the plant begins to bloom less and produce leaves massively.
We proceed at the end of March or November: we take out the basket and remove the rhizome, trying not to damage the roots. It is cleaned with a jet of water until the various parts are clearly visible: the main rhizome, the secondary ones, the roots and the buds.
Continue by sectioning the rhizome into segments of about 8 cm in length. The best derive from the secondary bifurcations of the rhizomes, as they are the youngest parts. Let's make sure that each segment has roots and at least one eye.
At this point we can reinsert one for each basket, recomposing it as we have already explained. Finally we will place it again at the bottom of the pond.

Pests and diseases of water lilies

There are several parasites that can affect water lilies.
First of all they are often attacked by black aphids, which weaken them as well as being possible carriers of viruses. If the condition is limited we can get rid of it quickly by putting the stems under water for a few seconds. Otherwise we can use specific insecticides for aquatic plants.
Another frequent pest is the galeruca. It is a small beetle that deposits the eggs near the plant. Later the larvae feed on the leaves by digging large galleries.
Eggs are easily identified as they are yellow in color and are often grouped together. The ideal is to monitor the area carefully and destroy them as soon as we see them. Their appearance is more frequent with increasing temperatures. In extreme cases we can use specific products.
Finally we point out the danger of cryptogams and rot. Also in this case the best solution consists in the constant monitoring of the plants and in the prompt elimination of all the affected leaves so that the disease does not spread. The water lily will not be disturbed since the production of leaves is always very abundant.
Prevention is also important. We position the pond in a sunny area, we avoid having too many specimens in the same area, we constantly check the pH of the water, which must never be too acidic or too alkaline.

Waterlily - Nymphea: Species and variety

The genus Nymphea includes about 50 species from Europe, Asia, Africa and the American continent. The hybridizations, begun already in the XIX century, have given life to a great number of varieties and cultivars, more or less rustic, and of the most varied dimensions. Here are some of the most widespread:

Water depthFirst nameleavesflowersOther characteristics

For small pools of water (h up to 40 cm)
Nymphaea tetragona
Up to 8 cm in diameter, slow development
Diameter up to 5 cm, white or yellow Water height from 20 to 50, ideal for amateurs on balconies or small ponds
Nymphaea pygmaea 'Rubra' Diameter up to 5 cm, dark pink with yellow center
It also exists white and yellow
Water height up to 40 cm
Nymphaea 'Laydekeri Lilacea' Up to 8 cm in diameter, with red edges Diameter up to 5 cm, pink and yellow pointed petals Even in just 20 cm of depth. Abundant flowering.

For medium bodies of water (40 to 80 cm deep)
Nymphaea 'Atropurpurea Dark green on the front and burgundy on the back 15 cm in diam., Pink and red, yellow heart Vigorous and floriferous
Nymphaea 'Odorata Sulphurea Grandiflora' Up to 20 cm in diameter, dotted with red Up to 14 cm in diameter, light yellow, perfumed 

For large ponds (more than 1 meter deep)
Nuphar lutea Up to 15 cm in diam Small flowers, above the water's surface, yellow Rapid growth, tolerates the partial shade
Nymphaea 'Attraction' Round, up to 20 cm in diam. Large, star-shaped, dark pink Very adaptable and floriferous

Non-rustic exotic water lilies
Nymphaea caerulea Up to 20 cm in diam. Up to 10 cm in diameter, above the surface of the water, lavender blue. Very beautiful color. Originally from Egypt
Nymphaea colore Up to 15 cm in diam. Up to 8 cm in diam., Blue blues Flowery and fragrant
Nymphaea Victoria Amazonica Up to 3 m of diam White, then pink, 40 cm in diameter Huge, native to the Amazon River basin

  • Water lily flower

    The water lily is an aquatic plant belonging to the nymphaeaceae family. Originally from Asia, it is now widespread

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