How often to water lily-of-the-valley shrub in California
In July in the Central Valley, established lily-of-the-valley shrub in loam needs a deep watering about every 8 days: about 8.8 gallons each time for a plant 4 feet across, about 7.6 gallons a week. Lily-of-the-valley shrub, also called Japanese pieris, is a slow, dense evergreen from the mountain thickets of Japan, China and Taiwan. New leaves open coppery red, and chains of fragrant white urn-shaped flowers hang from it in spring. It needs moist, acidic, organic soil that drains well, some shade in hot areas, and shelter from wind.
How often to water lily-of-the-valley shrub, month by month
Type your city above and the days between waterings and the gallons appear here, worked out from your city's climate table. Or read the figures by climate zone further down.
How this is worked out: established roots fill the top 1.5 feet of soil, and you water again when that soil has dried halfway. Loam soil holds about 1.5 inches of water per foot. Water the whole area the plant covers, and skip a watering after a good soaking rain.
How to tell it needs water
- Soil dry an inch or two down under the mulch in summer signals lily-of-the-valley shrub needs water
- Leaves curling and drooping at the tips during a warm afternoon can indicate thirst
- Leaf margins scorching brown in afternoon sun point to heat and dry soil together
- Wilting and branch dieback while the soil stays wet suggest root rot or Phytophthora from poor drainage
How to water it
- Water the shallow root zone under the branches with drip or a soaker hose
- Soak about 8 inches down, then water again as the top inch begins to dry
- Plant in acidic, organic soil that drains well, raised slightly where clay holds water
- Keep a layer of pine needle or bark mulch over the roots
- Shelter it from drying wind and hot afternoon sun
Through the seasons
Keep a new shrub evenly moist through its first two summers while roots spread. Established plants still want steady moisture, but soggy soil invites root rot. Mulch keeps the shallow roots cool. It is evergreen, with red new growth in spring, and its flower buds form on old growth. On the north-central coast and in the Central Valley, WUCOLS gives it a moderate water rating. WUCOLS marks it as not suited to the south coast, South Inland, the high desert or the low desert.
In pots
Lily-of-the-valley shrub grows well in a large pot of acidic, organic mix, which helps where garden soil is alkaline. Feel the mix an inch down, and when it is dry there, water slowly until it runs out the holes. In warm weather that can be every day or two. Pour off the saucer so roots never sit in water. Keep the pot in morning sun and afternoon shade. In winter, water when the mix starts to dry and keep the pot out of cold wind.
- A year
- 17.11 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Lily-of-the-Valley Shrub: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.37 | 0.4 | – | – | – | – |
| Feb | 0.53 | 0.65 | – | – | – | – |
| Mar | 0.87 | 1.09 | – | – | – | – |
| Apr | 1.18 | 1.52 | – | – | – | – |
| May | 1.46 | 2.08 | – | – | – | – |
| Jun | 1.61 | 2.48 | – | – | – | – |
| Jul | 1.61 | 2.67 | – | – | – | – |
| Aug | 1.49 | 2.39 | – | – | – | – |
| Sep | 1.24 | 1.8 | – | – | – | – |
| Oct | 0.87 | 1.18 | – | – | – | – |
| Nov | 0.47 | 0.56 | – | – | – | – |
| Dec | 0.31 | 0.34 | – | – | – | – |
| Year | 12 | 17.11 | – | – | – | – |
How this is worked out: the WUCOLS water rating for each zone times that zone’s climate for the month. A dash means WUCOLS does not rate the plant there. The figures are what the plant uses, before sprinkler losses.
Plants with the same water needs 16
Rated moderate water in the Central Valley, like lily-of-the-valley shrub. Plants that drink alike can share one valve and one schedule.
RosesRosa hybrids..bushmoderate water, Central Valley2.67 gal/sq ft in July
AzaleasRhododendron spp. (CA native and non-native spp.)moderate water, Central Valley2.67 gal/sq ft in July
CamelliasCamellia japonica (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in July
GardeniasGardenia spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in July
Bird of ParadiseStrelitzia reginae (shade in desert)moderate water, Central Valley2.67 gal/sq ft in July
HibiscusHibiscus rosa-sinensismoderate water, Central Valley2.67 gal/sq ft in July
Sago PalmCycas revolutamoderate water, Central Valley2.67 gal/sq ft in July
Star JasmineTrachelospermum jasminoides and cvs.moderate water, Central Valley2.67 gal/sq ft in July
ArborvitaeThuja occidentalis ssp. & cvs.moderate water, Central Valley2.67 gal/sq ft in July
BambooBambusa spp.moderate water, Central Valley2.67 gal/sq ft in July
LilacsSyringa hybrids (including Descanso hybrids)moderate water, Central Valley2.67 gal/sq ft in July
SpireaSpiraea spp. (CA native and non native spp.)moderate water, Central Valley2.67 gal/sq ft in July
Butterfly BushBuddleja davidii and hybridsmoderate water, Central Valley2.67 gal/sq ft in July
SageSalvia officinalis and cvs.moderate water, Central Valley2.67 gal/sq ft in July
Red BuckeyeAesculus paviamoderate water, Central Valley2.67 gal/sq ft in July
Western ServiceberryAmelanchier alnifoliamoderate water, Central Valley2.67 gal/sq ft in JulySimilar plants that need less water 16
Rated lower than lily-of-the-valley shrub in the Central Valley. Worth a look for a new bed or a lawn replacement.
LavenderLavandula spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
RosemaryRosmarinus officinalislow water, Central Valley1.07 gal/sq ft in July
BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Olive TreesOlea europaea ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Crape MyrtleLagerstroemia spp., hybrids & cvs.low water, Central Valley1.07 gal/sq ft in July
LantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in July
AloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
JunipersJuniperus spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
Russian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in July
SagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in July
Wild PrivetLigustrum vulgarelow water, Central Valley1.07 gal/sq ft in July
CoralberrySymphoricarpos orbiculatus (SHADE)low water, Central Valley1.07 gal/sq ft in July
Sydney Golden WattleAcacia longifolialow water, Central Valley1.07 gal/sq ft in July
Blue Leaf WattleAcacia salignalow water, Central Valley1.07 gal/sq ft in JulyTurn this into minutes on your water days
Every city page has a calculator that takes lily-of-the-valley shrub, your sprinkler type and the month, and gives the minutes per water day for that supplier's schedule. Or put it in a zone of the personal watering plan and get all twelve months printed.
Questions people ask
How much water does lily-of-the-valley shrub need per day?
In July in the Central Valley, established lily-of-the-valley shrub needs about 1.1 gallons a day for a plant 4 feet across and about 4.3 gallons a day for a plant 8 feet across. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.
Does watering for lily-of-the-valley shrub change across California?
Yes. WUCOLS rates lily-of-the-valley shrub separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, moderate water in the Central Valley zone, not suited to this region in the South Coastal zone, not suited to this region in the South Inland zone, not suited to this region in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
Is lily-of-the-valley shrub poisonous?
Yes, it carries a high severity poison rating. Keep children and pets from chewing leaves or flowers. Wear gloves when pruning.
When should I prune lily-of-the-valley shrub?
Prune right after it flowers. Next season's blossoms form on old growth, so later pruning removes them. Light shaping is usually enough.
Why is the new growth red?
Emerging leaves open coppery red and turn green as they mature. It is normal and one of the shrub's best features. It does not signal a water problem.
Can lily-of-the-valley shrub grow in alkaline soil?
It needs acidic soil with plenty of organic matter. In alkaline soil, grow it in a raised bed or pot of acidic mix. Mulch with pine needles or bark.
What pests bother lily-of-the-valley shrub?
Lace bugs and nematodes are the main pests, and leaf spot and dieback can occur. Stippled, pale leaves point to lace bugs. Check drainage if branches die back.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Pieris japonica (taiwanensis), the University of California survey California agencies use for landscape plan reviewRead August 23, 2026 on wucols.ucdavis.edu
- Model Water Efficient Landscape Ordinance, adopted text and appendices, effective 2025-01-02 · monthly reference evapotranspiration per city, Appendix CRead August 23, 2026 on water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/Water-Use-And-Efficiency/MWELO-Rulemaking/Final-MWELO-Text-and-Appendices_20250103.pdf
- UC Statewide IPM Program, irrigation scheduling using evapotranspirationRead September 30, 2026 on ipm.ucanr.edu/PMG/GARDEN/ENVIRON/evap.html
- Shaw and Pittenger, Landscape Irrigation System Evaluation and Management, UC Cooperative Extension, 2009Read September 30, 2026 on ucanr.edu/sites/default/files/2013-02/160836.pdf
- Pittenger, Water Management in Gardens and Landscapes, UC Riverside, 2017Read September 30, 2026 on ucanr.edu/sites/default/files/2017-03/258022.pdf