Water lily seeds: Nymphaea Caerulea (Blue Lotus)

Nymphaea Caerulea seeds close-up – blue seeds to scarify for waterlily culture

Star-shaped blue flower of Nymphaea caerulea open at the water surface

Blue water lily Nymphaea caerulea growing in a garden pond

Floating leaves and blue water lily flower in an ornamental pond

Blue water lily seeds Nymphaea caerulea

Name: Blue water lily seeds Nymphaea caerulea
Brand: Univers Aquaponie
Availability: InStock

$12.00

These seeds of Nymphaea caerulea produce the blue Egyptian water lily. Despite its common name of blue lotus, this plant is a true water lily: its leaves float on the surface, and its pale blue, star-shaped flowers open in the morning and close in the afternoon.

This tropical, non-hardy plant should be sown in heated water between 25 and 30 °C and overwintered in a frost-free environment. A mature specimen covers 1 to 1.5 m² of water surface.

Format : 20 seeds

20 seeds

40 seeds

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The summary

What you receive: seeds of Nymphaea caerulea, the botanical blue water lily, in a packet of 20 or 40 depending on the size chosen.
Seedling: sow from April to June, indoors, under 2 cm of water kept between 25 and 30 °C, in full light. Germination takes 3 to 4 weeks.
Hardiness: this tropical plant tolerates down to -1 °C and must therefore be brought in before frost each autumn in metropolitan France.
Space required: a mature plant covers 1 to 1.5 m² of water surface, at a depth of 30 to 60 cm.
Patience required: allow 2 to 4 years from seed to first flower, with floating leaves appearing from the first summer.
Use: this is an ornamental pond plant, sold freely in France.

Blue tropical water lily to sow, 1 to 1.5 m² per mature plant, not frost-hardy

The Nymphaea caerulea is the blue lotus of the Nile, the one depicted in ancient Egyptian frescos. Its common name of blue lotus is misleading, because botanically it is not a lotus at all: Nelumbo holds its leaves above the water on a rigid stem, while Nymphaea lays its leaves flat on the surface. If it is the upright habit you are after, take a look at Nelumbo nucifera lotus seeds instead.

A tropical plant, slow to flower

This is a tropical plant that tolerates down to -1 °C and no lower. Germination requires genuinely warm water, between 25 and 30 °C, you will get nothing from water at 18 °C. Allow two to four years from seed to first flower; the first season produces floating leaves and rarely any blooms. These seeds are therefore suited to those who are prepared to wait, not to those hoping for a flowering pond in the same summer.

🌿 Sow, prick out, install

In a germination tray

Sow in a tray of fine compost and sand, seeds covered by 1 mm, submerged under 2 to 3 cm of water at 25 to 30 °C, in full light.

At transplanting

Once two or three true floating leaves have formed, transplant one plant per pot filled with heavy soil and sand, under 5 to 10 cm of water.

In place

Place the basket 30 to 60 cm underwater, in full sun, in still water, with 6 to 8 hours of direct sunlight per day.

❄️ Winterising, every autumn

Before the first frosts, remove the basket and bring it inside to a frost-free location. You have two options: the first is to keep the rhizome dry in slightly damp sand, stored in a cellar between 10 and 15 °C; the second is to keep the plant growing in a heated tank at around 20 °C with supplementary lighting. The first is simpler and suits anyone without a well-lit space; the second gives you a head start of one season before flowering. The practical calendar sets out the tasks month by month.

In the pond, place the basket in calm water, away from jets and pump outlets, as water lilies do not tolerate constant turbulence against their leaves. Each flower opens in the morning and closes in the afternoon for 3 to 4 days, then submerges to form its seed capsule. Beyond that, maintenance is limited to removing spent leaves and dividing the crown in spring.

Water surface area per plant

A mature plant covers 1 to 1.5 m² of water surface, meaning a garden pond of 3 m² can take two to three plants, whilst a one-metre square terrace tub holds just one. Expect roughly half the packet to reach the planted-out stage, which means sowing five or six seeds to end up with two or three plants, keep the rest of the packet for the following season.

🌸 What the cover changes

Floating leaves are more than decoration: they shade the water column. Coverage of around one third of the surface substantially limits the development of filamentous algae and green water in midsummer by depriving phytoplankton of the light it needs. It also reduces the peak temperature in your pond and offers your fish shelter from aerial predators. Beyond half the surface, however, gas exchange is reduced and submerged plants are starved of light, which means dividing the rootstock in spring becomes a maintenance task rather than a simple propagation exercise.

Technical specifications

The plant

Botanical name: Nymphaea caeruleaAlso referenced as Nymphaea nouchali var. caerulea. A water lily, not a lotus in the botanical sense.
Hardiness: Down to -1 °CUSDA Zone 10 to 12. Not hardy enough to overwinter outdoors in mainland France.
Surface area per mature plant: 1 to 1.5 m²Spread of approximately 1 to 1.5 m across the water surface, to account for before propagating plants.
Water depth at maturity: 30 to 60 cmAbove the crown. The plant tolerates 25 to 90 cm of water
Flower: Pale blue, 10 to 20 cmStar-shaped, yellow stamen centre. Open in the morning, closed in the afternoon.
Flowering: From July to SeptemberIn mainland France, on an already established plant

Seedling and germination

Seedling period: From April to JuneIndoors or in a greenhouse. The limiting factor is water temperature, not the time of year.
Scarification: UnnecessaryUnlike Nelumbo lotus seeds, which do need to be filed
Water temperature: 20 to 30 °CGrowth slows noticeably below 18 °C
Water depth at seedling stage: 2 to 3 cmJust above the grow medium, no deeper. Seedlings need to reach the surface quickly
Sowing depth: 1 mm of grow mediumFine compost and sand. A simple veil to hold the seed in place
Light: EssentialLight triggers germination in this species. Do not cover the propagator
Germination time: 3 to 4 weeksAt 25 to 30 °C in full light. Below 20 °C, germination stops.
First flowering: 2 to 4 yearsFrom seed. The first season produces floating leaves, rarely flowers.

To the pond and the bag

Flower lifespan: 3 to 4 daysIt is then submerged to form the seed capsule
Leaves: Floating, up to 40 cmRounded and lobed, green then marked with brown at the end of the season
Exposure: Full sunAt least 6 to 8 hours of direct sunlight per day
Water movement: Calm waterKeep away from jets, waterfalls and pump outlets
Overwintering: Frost-free, essentialRhizome kept dry in damp sand between 10 and 15 °C, or in a heated tank at around 20 °C
Routine maintenance: Removal of spent leavesAnd crown division in spring, once a year, on specimens grown in baskets
Formats: 20 or 40 seedsThe number of seeds corresponds to the chosen size.
Seed size: Approximately 2 mmSmall and dark, not to be confused with the lotus seed, which is hard and the size of an olive.
Storage: In water, in the darkStore in water and in the dark, between 8 and 12 °C. Sow in the season following receipt.
Treatment: NoneUncoated and untreated seeds

To budget for separately

Basket and grow medium: Heavy soil and sandTwo thirds non-peaty garden soil, one third sand, in a slotted pond basket.
Heat at seedling stage: Water maintained at 25 to 30 °CHeating mat or heated seedling corner: below 20 °C, these seeds will not germinate.

18 further specifications are available in the detailed view.

In the box

20-seed pack

20 Nymphaea caerulea seeds
1 resealable packet labelled with the botanical name

40-seed pack

40 Nymphaea caerulea seeds
1 resealable packet labelled with the botanical name

Germination, spread, water depth, and hardiness: figures sourced from national botanical gardens and specialist growers, last checked on 10/09/2026. The values used are the most conservative for mainland France.

Blue water lily or Nelumbo lotus: two seeds, two very different growing methods

Both are sown in a pond and carry the word lotus, yet nothing is managed the same way, from seedling to overwintering.

Two aquatic plants that everyday language confuses The blue water lily is tropical: it tolerates down to -1 °C and must be brought under cover before the first frost each autumn. Several Nelumbo lotus varieties overwinter outdoors. That is the deciding factor first; leaf habit comes second.

	Leaves	Flower colour	Seed size	Scarification before sowing	Hardiness	Frost-free overwintering
Recommended Blue water lily seeds Nymphaea caeruleaYour choice	Flat on the water	Pale blue to lavender	Approx. 2 mm, tender	Unnecessary	Tropical, down to -1 °C	Required
Lotus seed pack for planting: Nelumbo Nucifera pinkYour choice	Upright above the water	Pink	Hard, olive-sized	Tegument to file	Several varieties overwinter outdoors	Depending on the variety

Blue water lily seeds Nymphaea caeruleaRecommended

Postage

LeavesFlat on the water

Flower colourPale blue to lavender

The seedling

Seed sizeApprox. 2 mm, tender

Scarification before sowingUnnecessary

In the pond

HardinessTropical, down to -1 °C

Frost-free overwinteringRequired

Lotus seed pack for planting: Nelumbo Nucifera pink

Postage

LeavesUpright above the water

Flower colourPink

The seedling

Seed sizeHard, olive-sized

Scarification before sowingTegument to file

In the pond

HardinessSeveral varieties overwinter outdoors

Frost-free overwinteringDepending on the variety

Growth habit, seed, seedling and hardiness recorded on 10 September 2026 from the two product pages in the shop: Nymphaea caerulea water lily seeds and Nelumbo nucifera pink lotus seeds.

Estimate your
delivery time

A packet of seeds is sent as a small parcel and can be grouped at no extra cost with the rest of your order. The exact amount is calculated at checkout. Outside France, please check the status of the species in your country before ordering: it is banned in Poland, Latvia and Russia, and regulated in the United Kingdom.

Frequently asked questions

6 questions

6 key questions

Is the sale and cultivation of Nymphaea caerulea permitted in France?

Yes, as far as we are concerned: the plant does not appear on the French list of controlled substances, and it is sold freely as an ornamental pond plant. It is not, however, authorised as a food product or dietary supplement within the European Union.

Its legal status varies from country to country. The species is banned in Poland, Latvia, and Russia, and is regulated in the United Kingdom under the Psychoactive Substances Act 2016. If you are ordering from one of these countries, please check the applicable regulations before placing an order: we are not in a position to do this on your behalf.

This product page describes ornamental cultivation only. No other use is offered, described, or recommended.

How to germinate Nymphaea caerulea seeds?

Fill a tray with fine compost mixed with sand, moistened and firmed down.
Place the seeds on the surface and cover them with approximately 1 mm of grow medium — no more.
Submerge the tray in just 2 to 3 cm of water.
Keep the water between 25 and 30 °C, in full light, without covering.
Replace some of the water every three days to limit algae growth.
Allow 3 to 4 weeks for germination, then prick out one seedling per pot as soon as two or three true floating leaves have developed.

Water temperature is the critical factor: below 20 °C, germination becomes very erratic. A heat source is essential, as with any early seedling described in our guide to setting up an indoor propagation space.

Should you scarify or file water lily seeds?

What is the difference between Nymphaea caerulea and the Nelumbo lotus?

Criterion	Nymphaea caerulea	Lotus Nelumbo
Habit	leaves lying flat on the water	leaves held upright above the water on a rigid stem
Seed	approx. 2 mm, soft	hard, olive-sized
Seedling	no scarification required	very hard seed coat, must be filed before soaking
Hardiness	tropical	several Nelumbo overwinter outdoors, rhizome must be kept frost-free

We stock both: pink Nelumbo nucifera lotus seeds and this page for the blue water lily. Our article on lotus in aquaponics goes into detail on the differences in cultivation.

What germination rate should you expect?

Can the blue water lily be grown in an aquarium or in aquaponics?

In a heated aquarium, yes, as long as the plant is young. It is actually a convenient way to get through the first winter, in water at around 20 to 25 °C with good lighting. A mature specimen, however, needs 1 to 1.5 m² of free surface area and quickly becomes unmanageable in a tank.

In aquaponics, the interest is ornamental, not nutritional. The plant is not a vegetable and does not consume nitrates at the rate of a food crop; it provides shade and decoration in the pond section of a system. Our article on lotus in aquaponics sets out the context, and the list of plants to grow in aquaponics shows what genuinely plays a nutritional role.

Growing calendar

These timings apply to mainland France and should be shifted by around two weeks depending on your region. The date matters less than the water temperature: that is what triggers or prevents germination.

Stage
Indoor seedlings3 months	Indoor seedlings: no	Indoor seedlings: no	Indoor seedlings: no	Indoor seedlings in April	Indoor seedlings in May	Indoor seedlings in June	Indoor seedlings: no	Indoor seedlings: no	Indoor seedlings: no	Indoor seedlings: no	Indoor seedlings: no	Indoor seedlings: no
Transplanting into pots3 months	Transplanting into pots: no	Transplanting into pots: no	Transplanting into pots: no	Transplanting into pots: no	Transplanting into pots in May	Transplanting into pots in June	Transplanting into pots in July	Transplanting into pots: no	Transplanting into pots: no	Transplanting into pots: no	Transplanting into pots: no	Transplanting into pots: no
Introducing to the pond3 months	Introducing to the pond: no	Introducing to the pond: no	Introducing to the pond: no	Introducing to the pond: no	Introducing to the pond: no	Introducing to the pond in June	Introducing to the pond in July	Introducing to the pond in August	Introducing to the pond: no	Introducing to the pond: no	Introducing to the pond: no	Introducing to the pond: no
Flowering3 months	Flowering: no	Flowering: no	Flowering: no	Flowering: no	Flowering: no	Flowering: no	Flowering in July	Flowering in August	Flowering in September	Flowering: no	Flowering: no	Flowering: no
Frost-free overwintering6 months	Frost-free overwintering in January	Frost-free overwintering in February	Frost-free overwintering in March	Frost-free overwintering: no	Frost-free overwintering: no	Frost-free overwintering: no	Frost-free overwintering: no	Frost-free overwintering: no	Frost-free overwintering: no	Frost-free overwintering in October	Frost-free overwintering in November	Frost-free overwintering in December

KeyIndoor seedlingsTransplanting into potsIntroducing to the pondFloweringFrost-free overwintering

This month September

Growing guidance

Seedling period: April to JuneIndoors, water temperature takes priority over the time of year
Water temperature at seedling stage: 25 to 30 °CBelow 20 °C, germination becomes very uneven
Water depth at seedling stage: 2 à 3 cmJust above the grow medium, no higher
Sowing depth: 1 mmA thin layer of fine compost and sand
Scarification: UnnecessaryUnlike Nelumbo lotus seeds
Germination time: 3 to 4 weeksConvergent value across the sources consulted
First flowering: 2 to 4 yearsFrom seed, not from transplanting
Surface area per mature plant: 1 to 1.5 m²This figure determines the quantity to order
Water depth at maturity: 30 to 60 cmAbove the collar, reached gradually
Exposure: Full sun6 to 8 hours of direct sunlight per day
Hardiness: -1 °CZone USDA 10 to 12, frost-free overwintering required
Crown division: Once a yearIn spring, on specimens grown in a basket

What you need to know

The water temperature is the one parameter that makes or breaks germination. A propagator placed on a radiator or a heat mat will sprout; the same propagator on a windowsill at 18 °C will not, and the seeds are wrongly assumed to be faulty.
Do not cover the propagator with an opaque sheet: in this species, light plays a part in triggering germination. A transparent lid is suitable for retaining warmth; a piece of cardboard is not.
Do not swamp the seedlings. At sowing, 2 to 3 cm of water is sufficient, and the level should only be raised as the leaves reach the surface. A seedling that cannot reach the light will exhaust itself within a few days.
Replace part of the water in the propagator every three days. In warm, well-lit water, filamentous algae establish themselves quickly and smother young shoots.
Use a heavy garden soil mixed with sand — never a peat-based compost from a garden centre: peat compost floats, clouds the water for weeks, and feeds algae far more than it feeds the plant.
Keep the basket away from any waterfall, jet, or pump outlet. Nymphaea tolerates constant water movement poorly — its leaves tear and flowering becomes less frequent.
Remove the basket before the first night at zero degrees, not after. The plant can withstand down to -1 °C, but a single hard frost is enough to lose a three-year-old plant.
Divide the rootstock in spring, once a year. A rhizome left overcrowded in its basket for several seasons will produce an abundance of leaves and fewer and fewer flowers.

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Blue water lily seeds Nymphaea caerulea

The summary