Ornamental · Nymphaeaceae
Water Lily
Nymphaea
Give it a sunny spot and calm water, and a water lily keeps flowering from late spring right into fall.
Full sun
USDA 3–11
3–10 in · 8–25 cm
Overview
Want to make a pond feel finished? A water lily does it fast. It's a true aquatic, so the roots sit in a submerged pot of heavy soil while the round pads and cupped flowers float up top. And despite the name, it's not a real lily at all, which is a big deal if there's a cat around.
There are two main kinds, and picking one is easy. The hardy types come back every year across zones 3 to 11, shrugging off cold winters as long as the crown stays below the ice. The tropical types go bolder with blues and purples, and some even open at night, but they're tender, so most folks just grow them as annuals where the water freezes.
So what does it actually want? Two things: plenty of sun and water that sits still. Give it a bright, calm spot away from any fountain and it'll spread its pads and bloom for months. Skimp on the light or let the water move, though, and you'll end up with lots of leaves and barely a flower.
Care
The short version: it wants full sun and still water, with the crown tucked into a pot of heavy soil under about 6 to 18 inches of water. Feed it monthly while it's growing, split the clump every few years, and it'll keep the flowers coming.
Light
Water lilies really do bloom for the sun, so give them at least 6 hours of direct light a day, and full sun gets you the most flowers. They'll hang on in partial shade, sure, but you'll see way more leaf and a lot fewer blooms.
Water
This one's a true aquatic, so it lives in standing water, crown down in a submerged pot and pads floating up on top. Shoot for around 6 to 18 inches (15 to 46 cm) of water over the crown depending on the cultivar, and keep it calm. Fountains and pumps just stir things up, and a water lily can't stand moving water.
Soil
Set the crown into heavy clay loam or aquatic media in a submerged pot, then cap it with gravel so the soil stays put. Any pH from 6.0 to 8.0 works fine, so honestly the heavy mix matters way more than fussing over how acidic it is.
Temperature
Hardy water lilies are surprisingly tough, taking anything from about -40°F to 100°F (-40°C to 38°C) as long as the crown stays below the ice all winter. Just plant the pot deep enough that the crown never freezes solid and you're good.
Humidity
Sitting out on open water, a water lily's already in high humidity, so there's really nothing to do here. The pond's got it covered.
Feeding
These plants are hungry, no way around it. Push an aquatic fertilizer tablet into the soil under the gravel about once a month through spring and summer, and that feeding is what turns a few shy flowers into a steady show.
Pruning
Just keep up with the dead stuff. Pinch off spent flowers and yellowing pads as they show up to push more bloom and keep rotting leaves out of the water, and that's about it.
Repotting
A water lily doesn't need repotting so much as dividing every few years. When the flowers thin out, the pads start poking up out of the water, or the pot's crammed with rhizomes, that's your cue to lift it and split the clump.
Size & spacing
The plant stays low, just 3 to 10 inches (8 to 25 cm) above the water, but those pads spread way out, anywhere from 2 to 12 feet (61 cm to 3.7 m) across depending on the cultivar. Pick one whose spread fits your pond so it doesn't take over the whole surface.
When to plant
Here's the thing: a water lily doesn't watch the calendar, it watches the water. Drop the rhizomes into their submerged pots in spring once the cold's gone and the water's warming up, and you'll get flowers across the surface from late spring through fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Set rhizomes or tubers in submerged containers in spring once water has warmed and frost danger has passed.
- Harvest: Late spring through fall (flowers rest on or just above the water).
Hardiness
USDA hardiness zones: 3–11
Temperature: down to -40°C
Troubleshooting
Most water lily hiccups come down to the same few things, not enough sun, the wrong depth, or a clump that's gotten too big, plus a couple of pests that hang out on the pads. Spot the early signs below and you can sort it out before the flowers quit. Find what matches, then go fix it.
Tons of pads but where are the flowers?
If it's all leaf and no bloom, the usual suspect is too much shade, less than the 6 hours of direct sun it takes to set buds. A crown planted too deep, a clump that's outgrown its pot, or water churned up by a fountain can hold things back too. Move it into full sun and still water, raise it to the right depth, divide a crowded rhizome, and feed it through the season, and the flowers should follow.
Fix:
- Move the container so the plant gets at least 6 hours of direct sun
- Raise the container so the crown sits at the recommended depth for the cultivar
- Lift and divide the rhizome every few years
- Relocate away from fountains or pump outflow so the plant sits in still water
- Fertilize with aquatic plant tablets during the growing season
Little green clusters piling up on the pads and buds
Those clusters? Those are waterlily aphids, tiny soft-bodied bugs that gather on the tops of the pads and on the buds. Good news, the fix is easy: just hose or brush them off into the water, where they can't climb back and the fish usually eat them. Any pad that's really covered, go ahead and pull it.
Fix:
- Hose or brush the aphids off the pads into the water, where they cannot climb back and fish may eat them
- Remove and discard heavily infested pads
Pads turning yellow or chewed full of holes
A few evenly yellow old pads? That's just age, nothing to worry about. But ragged holes and chewed edges usually mean waterlily beetle, leaf-mining midges, or china-mark moth are feeding, while spots or soft brown patches can point to leaf spot or crown rot. Snip off the marked pads, pick off any beetles and larvae or flick them into the water, and add a fertilizer tablet if it looks hungry.
Fix:
- Remove and discard yellow, spotted, or chewed pads
- Pick off beetles and larvae or knock them into the water
- Fertilize with aquatic plant tablets if a deficiency is suspected
Toxicity
Got pets? You can breathe easy with this one. A water lily isn't a true lily, so it doesn't carry any of the kidney danger that real lilies and daylilies bring to cats. It's not on the ASPCA toxic list, and cats, dogs, and everybody else in the house are just fine around it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Totally fine for cats. Since it isn't a true lily, it doesn't carry any of that kidney risk that makes Lilium and daylilies so dangerous to them.
Dogs None
Nothing to worry about with dogs. If one wades in and mouths a floating pad, no harm done.
Horses Safe
It's not listed as a hazard for horses, and honestly a pond plant hardly ever ends up within reach of one anyway.
Rabbits Safe
Safe for rabbits too, with none of the toxic stuff that would give them trouble.
Livestock Safe
Cattle, goats, and sheep can graze near the pond no problem, since the leaves and flowers won't hurt them.
Birds Safe
Harmless to birds and waterfowl, which love to pick at the pads and seeds out in the wild.
People Safe
No danger to people either, kids included, even when little hands reach into the water to touch the floating flowers.
Grown in an outdoor pond, so casual contact by pets or children is uncommon; no special handling required.
Varieties
There are hundreds of water lilies out there, and they split into two camps: the hardy ones that overwinter in the pond and the tender tropicals grown for punchier color. Here are the ones worth knowing by name.
'Attraction'
It's a hardy crowd-pleaser for zones 3 to 8 with fragrant red flowers, and it's still one of the most widely planted cultivars you'll find.
'Marliacea Chromatella'
This hardy one handles zones 4 to 10, showing off canary-yellow cupped flowers over copper-mottled pads from May all the way to frost.
'Director George T. Moore'
It's a tropical day-bloomer that lifts violet-blue flowers up above the water, and where winters get cold folks just grow it as an annual.
Tropical day- and night-blooming water lilies
These tender Nymphaea suit zones 9 to 11, or you can grow them as annuals, and they bring blue and purple shades plus night-opening flowers no hardy lily can pull off.
Lotus (Nelumbo)
Don't be fooled, this isn't a water lily but a whole separate genus in its own family, holding round leaves and flowers up high instead of floating them on the water.
How to propagate
Making more water lilies? Turns out it's pretty simple, and almost everyone does it the same way, by splitting a plant they already have instead of messing with seed.
DivisionEasy
Spring · One growing season
Splitting one in spring is the go-to way to make more water lilies, and it's the easiest too. Just lift the rhizome, cut it into chunks that each keep a growing point, and replant them lying flat with the bud end up in a submerged pot of heavy soil. Each piece settles in over one growing season, so plan to divide every few years once the clump gets crowded and the flowers start thinning out.
SeedModerate
Spring to summer · One or more seasons
Seed does work for the wild species, though it can take a season or more to get going if you sow it in spring or summer. For the garden it's usually not worth the wait, since most named cultivars are sterile hybrids that won't come true, and they do way better split by division anyway.
Myths
Water lilies are true lilies, so they're deadly to cats just like the lilies that cause kidney failure.
Here's the truth: the water lily (Nymphaea) isn't a true lily and isn't part of that dangerous group at all. The plants that cause sudden, often deadly kidney failure in cats are the true lilies (Lilium) and daylilies (Hemerocallis), which aren't related to it. A water lily in your pond is no threat that way, and it's not on the ASPCA toxic list. Keep the real lilies and daylilies away from cats, but don't lump this aquatic plant in with them.