Key takeaways
- Match the variety to your pond depth, from 15-30cm for miniatures to 60cm or more for vigorous types
- Plant in a lattice aquatic basket of aquatic compost, never multipurpose
- Top the compost with 2cm of washed gravel to keep it in place
- Start the basket high on bricks and lower it in stages as the leaves grow
- Give lilies full sun and still water, well away from fountains
- Feed with aquatic fertiliser tablets pushed into the compost, not liquid feed
A water lily flowers when it’s planted at the right depth, in full sun and in still water. Get those three things right, use a proper aquatic basket and compost, and lower it gently, and you should see flowers within its first summer or two.
This guide covers planting a hardy water lily from start to finish. For other plants to go alongside it, see our guide to the best pond plants for UK gardens.
What depth does a water lily need?
Water lilies come in different sizes, and each needs a different depth of water above its crown (the growing point on top of the root). Always check the label before you buy.
Miniature lilies are happy in just 15-30cm of water, so even a half-barrel on the patio can grow one.
| Lily size | Water above the crown | Suits | Example varieties |
|---|---|---|---|
| Miniature | About 15-30cm | Tubs, half-barrels, tiny ponds | ’Pygmaea Helvola’ |
| Small | About 30-45cm | Small garden ponds | ’Froebelii’ |
| Medium | About 30-60cm | Most garden ponds | ’James Brydon’ |
| Vigorous | 60cm or more | Large ponds and lakes | ’Gladstoneana’, native Nymphaea alba |
Too deep, and a small lily struggles to send leaves up to the surface. Too shallow, and a vigorous lily throws up a mass of leaves that stand out of the water and smother the pond. In a small pond, choose a small or miniature variety.
The right basket and compost for a water lily
Plant your lily in a lattice aquatic basket filled with aquatic compost. The holes let water reach the roots, and the heavy compost holds the plant down.
- Basket size: go generous. A basket around 25-30cm across suits most small and medium lilies for a few years. Vigorous types need a bigger one.
- Liner: fine-mesh baskets don’t need one. Older wide-mesh baskets need a square of hessian to stop compost washing out.
- Compost: use aquatic compost, or a heavy garden loam with no manure or fertiliser in it.
- Gravel: have some 10mm washed gravel ready to cover the top.
Never use multipurpose compost. It’s too light, so it floats out and clouds the water. Its nutrients also leak into the pond and feed algae.
How to plant a water lily step by step
Plant on a mild day between late April and June. It takes about 20 minutes.
- Wet the compost first. Fill the basket about two-thirds full, then pour pond water through until it’s soaked. Dry compost bursts into a cloud of silt when it goes underwater.
- Position the rhizome. Lay the thick root (the rhizome) on the compost and fill around it. Leave the growing tip just showing above the surface. Burying the crown can make it rot.
- Firm it in. Press the compost down well around the root.
- Add feed. Push an aquatic fertiliser tablet into the compost near the roots, following the pack.
- Top with gravel. Spread a 2cm layer of washed gravel over the compost, keeping it clear of the growing tip. This stops compost floating off and fish digging.
- Lower it gently. Soak the basket again, then lower it into the water at a slight angle so trapped air can escape.
Leave the growing tip just showing above the compost. Then top with gravel to keep everything in place.
How to lower a new water lily in stages
Don’t drop a new lily straight to the bottom. Its young leaves need light, and they can’t reach the surface through deep water.
Stand the basket on bricks, an upturned crate or a stack of empty baskets so the leaves float on the surface. As new leaves appear, lower the basket by a layer every couple of weeks. Keep going until it sits at its final depth.
Start high on bricks, then take a layer away every couple of weeks. The leaves always stay near the light.
How to feed a water lily
Feed with aquatic fertiliser tablets from late spring to late summer. Push them deep into the compost, following the pack rate, and cover the hole with gravel. This puts the feed where the roots are, not in the water.
Never use ordinary liquid feed or lawn fertiliser anywhere near a pond. It feeds the algae first and can turn the water green. In a wildlife pond, keep feeding to a minimum. Our guide to building a wildlife pond explains why low-nutrient water suits frogs and dragonflies.
Push the tablet well down and cover the hole. The feed then goes to the roots rather than the algae.
Why is my water lily not flowering?
A water lily that won’t flower is usually telling you about one of these five things. All of them can be fixed.
Full sun, still water and room to spread: that’s what makes a water lily flower freely.
- Moving water. Lilies love still water. A fountain or waterfall splashing the leaves makes them rot. Keep lilies well away from moving water.
- Too much shade. They need full sun, ideally six hours or more. Shrubs that have grown over the pond are a common culprit.
- Too deep, too soon. A new lily dropped straight to the bottom often just sulks. Raise it on bricks and lower it again in stages.
- Overcrowding. After several years, the leaves stand up out of the water and flowers get fewer. Lift and divide it in late spring.
- Hungry plant. Aquatic compost holds little food. Push in fertiliser tablets each spring.
Fish can also be a nuisance. Large goldfish and koi dig in baskets and nibble young shoots. A thicker layer of cobbles over the compost helps.
Water lily care through the year
| Month | Job |
|---|---|
| April to June | Plant new lilies. Lift and divide crowded ones. Push in feed tablets |
| June to September | Enjoy the flowers. Remove yellowing leaves and spent blooms |
| October to November | Cut back dying leaves so they don’t rot in the pond |
| December to March | Leave hardy lilies to rest at the bottom of the pond |
Once a lily is settled, it needs little more than an annual feed and a tidy-up. Our guide to maintaining a garden pond covers the rest of the pond’s yearly jobs.
Common water lily mistakes
- Choosing the wrong size. A vigorous lily in a small pond soon covers it. Match the variety to your depth and pond size.
- Using multipurpose compost. It floats out and clouds the water. Use aquatic compost or heavy loam.
- Burying the crown. Keep the growing tip just above the compost.
- Dropping it straight to the bottom. Lower it in stages so the leaves reach the light.
- Planting near a fountain. Splashed leaves rot and flowers dry up.
- Leaving it to cover the pond. Lily leaves should cover no more than about half the surface, so light still reaches other plants.
If your water turns green after planting, our guide to clearing green pond water can help. Our oxygenating pond plants also help keep it clear. For more water garden projects, see our garden design ideas.
Frequently asked questions
What depth should a water lily be planted at?
It depends on the variety, so check the label. Miniature lilies want about 15-30cm of water over the crown. Medium types like 30-60cm, and vigorous ones 60cm or more.
Can I use multipurpose compost for a water lily?
No, it floats out and clouds the water. Multipurpose compost is too light and its nutrients leak into the pond and feed algae. Use heavy aquatic compost or a plain garden loam.
Why is my water lily not flowering?
Usually too much shade, moving water or the wrong depth. Lilies need full sun and still water. Old, crowded clumps also stop flowering until they’re divided.
When is the best time to plant a water lily in the UK?
Late April to June, once the water has warmed up. The lily then has the whole summer to root in before winter. Avoid planting in autumn, when growth is slowing down.
Do water lilies need feeding?
Yes, with aquatic fertiliser tablets in late spring and summer. Push them deep into the compost so the feed goes to the roots. Never use ordinary liquid feed, which turns the water green.
Can a water lily grow in a small container pond?
Yes, if you choose a miniature variety. ‘Pygmaea Helvola’ is a small yellow lily that suits a half-barrel or large tub. Vigorous types will swamp a container in a season.
Now your lily is planted, read our container pond ideas for small gardens to add a miniature lily to a patio or balcony too.
Our team produces practical UK gardening guidance from source research, contributor records and established horticultural practice. Editorial standards are overseen by Matt W.
