Growli
Let's go

Plant care

Nymphaea 'Chromatella' (Yellow Waterlily) care

Nymphaea 'Chromatella'

Also called Yellow Waterlily, Chromatella Waterlily.

RHS H5USDA 4-11Mildly toxic to petsIndoor Spread 0.9-1.2 m (3-4 ft) of surface coverage

Watering rhythm

Direct sun (at least 4-6 hours)

Permanently submerged; keep pond level steady

Jump to schedule→Get smart reminders in the app

Light

Direct sun (at least 4-6 hours)

Soil

Heavy clay loam aquatic compost

Humidity

Ambient (aquatic)

Temp

15-30°C

Pet safety

Mildly toxic to pets

Mature size

Spread 0.9-1.2 m (3-4 ft) of surface coverage

Care at a glance

Light

Aim for at least 4-6 hours of direct sun on the leaves. Full sun for best bloom, though 'Chromatella' is more shade-tolerant than most and will still flower with around 4-5 hours of direct light. Six or more hours gives the heaviest flowering. If your only bright window faces south, that's perfect for nymphaea 'chromatella' — same window any aroid would fry on.

Watering

Watering nymphaea 'chromatella': permanently submerged; keep pond level steady. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. Grow in still water 30-60 cm (12-24 in) deep over the crown; a versatile range that suits modest garden ponds. Keep clear of fountain turbulence. Replace summer evaporation to hold planting depth.

Soil and pot

Nymphaea 'Chromatella' grows best in heavy clay loam aquatic compost. Set the rhizome horizontally in a mesh aquatic basket of heavy loam or aquatic compost, capped with washed gravel. Avoid floating organic mixes and peat, which cloud the water and starve the plant. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Nymphaea 'Chromatella' sits happiest at around Ambient (aquatic) humidity and 15-30°C (59-86°F). Not applicable as a percentage - foliage floats on the surface and roots stay submerged. Water depth and clarity govern culture, not air moisture. If you keep the room above 15 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed nymphaea 'chromatella' sparingly. Push aquatic fertiliser tablets into the basket roughly monthly from late spring through summer. Never scatter loose feed into the pond - dissolved nutrients trigger green-water and blanketweed. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on nymphaea 'chromatella' in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Few blooms in shade — Though shade-tolerant, it still rewards more sun. If flowering is sparse, increase direct light to 5-6 hours and confirm the crown is not buried too deep.
  • Waterlily aphids — Small aphids mass on buds and emergent pads. Spray them off into the water with a hose for fish to consume; skip insecticidal oils that smother the leaf surface.
  • Leaf spot / crown rot — Brown blotches or a soft, foul-smelling crown indicate fungal leaf spot or rot, often from stagnant warm water. Remove affected pads, improve water movement at the margins, and divide if the crown softens.
  • Overcrowding — Vigorous rhizomes fill the basket and push pads above the surface in a congested dome. Divide every 3-4 years in spring, keeping a strong growing tip and discarding spent rhizome.

Propagation

Divide the rhizome in spring. Lift the basket, sever sections each carrying a growing eye and roots, and pot into fresh aquatic loam under a gravel cap. Seed does not reproduce the cultivar, so division is the only true-to-type route. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Nymphaea 'Chromatella' is mildly toxic to pets. Nymphaea is not individually listed in the ASPCA toxic/non-toxic database; the ASPCA's dangerous 'lily' listings are Lilium and Hemerocallis, which are unrelated genera. As Nymphaea status is unconfirmed and chewing the pads has anecdotally caused GI upset (drooling, vomiting, lethargy) in pets, treat with caution and verify with a vet rather than assuming pet-safe. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Nymphaea 'Chromatella' care — frequently asked questions

What is the common name for Nymphaea 'Chromatella'?

Nymphaea 'Chromatella' is most commonly called Nymphaea 'Chromatella', but it is also known as Yellow Waterlily, Chromatella Waterlily. The names refer to the same species, so care instructions for Nymphaea 'Chromatella' apply identically to anything sold as Yellow Waterlily.

How much light does nymphaea 'chromatella' need?

Nymphaea 'Chromatella' grows best in direct sun (at least 4-6 hours). Full sun for best bloom, though 'Chromatella' is more shade-tolerant than most and will still flower with around 4-5 hours of direct light. Six or more hours gives the heaviest flowering.

How often should I water nymphaea 'chromatella'?

Water nymphaea 'chromatella' permanently submerged; keep pond level steady. Grow in still water 30-60 cm (12-24 in) deep over the crown; a versatile range that suits modest garden ponds. Keep clear of fountain turbulence. Replace summer evaporation to hold planting depth. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is nymphaea 'chromatella' toxic to cats and dogs?

Nymphaea 'Chromatella' is mildly toxic to pets. Nymphaea is not individually listed in the ASPCA toxic/non-toxic database; the ASPCA's dangerous 'lily' listings are Lilium and Hemerocallis, which are unrelated genera. As Nymphaea status is unconfirmed and chewing the pads has anecdotally caused GI upset (drooling, vomiting, lethargy) in pets, treat with caution and verify with a vet rather than assuming pet-safe.

What USDA hardiness zone does nymphaea 'chromatella' grow in?

Nymphaea 'Chromatella' is rated for USDA zone 4-11 (hardy waterlily; overwinters as a submerged rhizome) and RHS hardiness H5. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Nymphaea 'Chromatella' deep-dive guides

Every aspect of nymphaea 'chromatella' care, each with its own calibrated guide:

Featured in these plant shortlists

Nymphaea 'Chromatella' qualifies for 2 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Nymphaea 'Chromatella' is also commonly called Yellow Waterlily or Chromatella Waterlily.