How to care for a water lily: the care calendar, from planting to overwintering

A water lily that flowers generously in its first year, then produces only dense leaves that rise out of the water: this is one of the scenarios we hear most often at the garden center counter. A hardy water lily (Nymphaea) requires little work, but that work must be done at the right time: repotting every three to four years, a little fertilizer in spring, removing dead leaves, and providing the right depth. Here is the care schedule we follow for the water lilies in our display ponds in Nodebais.

The three basic conditions, before any maintenance

Half of the "sick" water lilies people show us are simply in the wrong place. Before looking for a miracle fertilizer, check three things.

Sunlight. A water lily needs at least five to six hours of direct sunlight per day to flower properly. In partial shade, it produces leaves but few flowers.

Still water. It hates turbulence: not under a waterfall, not in front of a pump outlet or a fountain jet. Leaves that are constantly wet on top will rot.

The right depth. Each variety has its own range, measured between the top of the basket and the water's surface.

These figures are approximate; the label for your variety takes precedence. A water lily planted too deeply exhausts itself raising its leaves, while one planted too shallowly freezes in winter and flowers poorly in summer.

Spring: awakening, fertilizer, and possible repotting

When the water rises above about ten degrees and the first reddish leaves come up toward the surface, the water lily wakes up. This is the time to intervene if necessary.

If you lowered it to the bottom for winter, gradually raise it back to its shelf, in several stages if possible. Then apply a fertilizer specifically for aquatic plants, in the form of tablets or cones pushed into the soil in the basket, never into open water: dissolved fertilizer would mainly feed algae.

Repotting is also done during this period, when growth resumes. It is easy to recognize: the leaves overlap and stand upright out of the water instead of spreading, flowers become scarce, and the crown overflows from the basket.

How to divide and repot a water lily, step by step

1. Take out the basket and place it in the shade on a damp tarp. Work quickly so the roots do not dry out.
2. Expose the crown (the rhizome) and rinse it with a gentle stream of water to see the “eyes,” the buds from which the leaves emerge.
3. Using a clean knife, cut sections ten to fifteen centimeters long, each bearing at least one vigorous eye. Discard old, hollow, or soft parts.
4. Fill a wide, shallow basket with heavy, clay-based soil or potting mix specifically for water lilies. Avoid universal potting mix, which is too light, floats, and clouds the water.
5. Place the rhizome almost flat, slightly tilted, with the bud level with the soil surface.
6. Cover with a layer of washed gravel to weigh it down and prevent fish from rummaging.
7. Place the basket at a shallow depth first, then lower it to its final depth when the leaves reach the surface.

A single divided water lily often produces two or three plants. Keep one and give the others away: this is how most varieties are shared among enthusiasts.

Summer: regular cleaning that makes all the difference

During the warm season, maintenance comes down to one task repeated every week or two: remove yellowing leaves and faded flowers. Cut the stem as low as possible, close to the clump, using long-handled pruning shears or your hand. A dead leaf left in place sinks, decomposes, and feeds sludge and algae.

\A healthy water lily ideally covers between one-third and half of a pond's surface: beyond that, thin it out by cutting healthy leaves.\ Too much cover reduces the light available to oxygenating plants and limits gas exchange at the surface.

Also watch for pests. Water lily aphids form dark colonies on the leaves and buds: a jet of water is enough to knock them off, and the fish will take care of them. Winding tunnels in the leaves indicate larvae of small midges (chironomids), while the water lily beetle, a small beetle, gnaws the surface of the leaves; simply remove the most affected leaves. Never use insecticide in a pond.

Autumn and winter: let the water lily prepare

In autumn, the leaves turn yellow en masse. Remove them as they appear, without cutting the young leaves that are still green at the center of the clump. A final thorough cleaning before the first frosts greatly reduces winter sludge.

Hardy water lilies easily withstand our Belgian winters, provided the clump remains below the frost line. In a deep pond, leave them in place. In a shallow pond or an above-ground container, lower the basket to the deepest point, or bring it indoors in a bucket of water in the garage, protected from frost. Tropical varieties, which are rarer here, must absolutely be overwintered in a warm place.

Common problems and their causes

• \Lots of leaves, no flowers\: not enough sun, the clump is too crowded, or the fertilizer has run out.
• \Leaves standing above the water\: the water lily is too cramped and needs to be divided.
• Rotting leaves: agitated water, splashing, or a plant that is too deep at the beginning of the season.
• Gnawed leaves and uprooted crown: large koi carp love water lilies; protect the basket with a grate or stones.

Also read

To choose the right container for your plants: Use perforated baskets rather than conventional pots for your aquatic plants.

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Frequently asked questions

— When should a water lily be divided?

In spring, when growth resumes, approximately every three to four years, or as soon as the leaves rise above the water.

— Why isn't my water lily flowering?

Most often due to a lack of sunlight, because the crown is too cramped in its basket, or because the soil is depleted.

— Should yellow water lily leaves be cut off?

Yes, as low as possible on the stem. Left in the water, they decompose and feed sludge and algae.

— Can a water lily remain in the pond in winter?

Yes for hardy varieties, provided the crown is below the frost line. In a shallow container, move it indoors to shelter.

In summary

• Full sun, still water, and sufficient depth: without these three conditions, no care will make up for it.
• Apply fertilizer tablets to the soil in spring, never to the water.
• Divide and repot every three to four years, in heavy soil and a wide basket.
• Regularly remove yellowing leaves to limit sludge and algae.
• Overwinter hardy varieties in place, below the frost line.

Last updated: September 29, 2026.