How often to water false hiba cedar in California
In July in the Central Valley, established false hiba cedar 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. False hiba cedar is 'Nana', a dwarf, mounding form of hiba arborvitae, a conifer from the cool, moist forests of Japan. It builds a spreading bun of bright green, scale-like foliage marked with silver beneath. After ten years it is only about a foot tall and 3 feet wide. Like the species, it needs moist, well-drained soil and does not tolerate drying out.
How often to water false hiba cedar, 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
- Foliage browning at the tips in a dry spell shows the roots have dried, since this conifer does not tolerate dry soil
- If the soil under the mound is dry an inch or two down in summer, give it a slow soak
- Yellowing, thinning foliage over soggy ground points to poor drainage, since it needs moist but well-drained soil
- Bronzed, burned foliage after cold, drying winds is winter burn, not thirst
- Fine webbing or tiny insects on the foliage point to mites or scale rather than a watering problem
How to water it
- Water at the edge of the mound with drip or a soaker, wetting the soil about 8 inches deep
- Keep the soil evenly moist, watering again before the top inch or two dries
- Plant in moist, well-drained, neutral to acid soil in sun or light shade
- Shelter it from strong or cold drying winds, and from hot afternoon sun inland
- Mulch the root zone to keep it cool and moist, and widen watering as the mound spreads
Through the seasons
Keep a new plant evenly moist through its first summers while roots spread. It is evergreen, and the foliage stays bright green through winter. Summer heat and drying wind are the hard part, so steady moisture and some afternoon shade matter most from late spring to early fall. Winter rain usually covers it on the north-central coast and in the Central Valley. WUCOLS rates false hiba cedar moderate water on the north-central coast and in the Central Valley. WUCOLS has not evaluated it for the south coast, South Inland, the high desert or the low desert.
In pots
Slow, low growth of only 2 to 4 inches a year lets false hiba cedar live for years in a wide container. Pick a container with open holes and a moisture-holding but free-draining mix. Through summer, feel the mix daily and add water before the surface inch dries out, because this conifer does not tolerate drying. Let excess drain, then empty the saucer. Shield the pot from hot afternoon sun and drying 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
False Hiba Cedar: 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 false hiba cedar. 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 false hiba cedar 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 false hiba cedar, 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 false hiba cedar need per day?
In July in the Central Valley, established false hiba cedar 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 false hiba cedar change across California?
Yes. WUCOLS rates false hiba cedar 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 evaluated in the South Coastal zone, not evaluated in the South Inland zone, not evaluated in the High and Intermediate Desert zone, not evaluated in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
How big does false hiba cedar get?
It grows only 2 to 4 inches a year. A decade-old plant stands roughly 12 inches high and spreads to around 40 inches, a low bun shape.
Can false hiba cedar take drought?
No. Hiba arborvitae is intolerant of drought and dry soil. Keep the root zone evenly moist and mulched through summer.
Does false hiba cedar need shade?
It grows in full sun or light shade. Where summers are hot, afternoon shade and shelter from wind help it most.
Why are the tips turning brown in winter?
Cold, drying winds can cause winter burn on the foliage. Plant it in a sheltered spot, and water before a dry winter spell.
Is false hiba cedar a true cedar?
No. It is a dwarf form of hiba arborvitae, a member of the cypress family from Japan. The name cedar is only a common name.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Thujopsis dolabrata 'Nana', 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