How often to water spurge olive in California
In July in the Central Valley, established spurge olive in loam needs a deep watering about every 20 days: about 8.8 gallons each time for a plant 4 feet across, about 3.0 gallons a week. Spurge olive is a small, dense evergreen shrub from rocky slopes of the western Mediterranean, usually 1 to 3 feet tall. Its narrow, leathery leaves somewhat resemble an olive's, and bright yellow late spring flowers give way to red fruits that dry to black. Established plants want sparse summer water, and any water they get must drain away fast.
How often to water spurge olive, 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 3 to 4 inches down at the edge of a young spurge olive means its root ball is ready for a soak
- Soft new shoots that wilt on a young plant during summer heat, with dry soil below, can point to thirst
- A single dead stem now and then is normal even on a healthy spurge olive, so trim it out rather than adding water
- Several stems dying back while the soil stays wet after summer watering can point to poor drainage rather than drought
- Red fruits drying to black in summer and fall are a normal stage and not a sign of drought
How to water it
- Water a new spurge olive over its root ball and just beyond it, widening the wet band as it spreads toward 4 or 5 feet
- Soak slowly until the soil is moist about a foot down, then let it dry several inches down before the next soak
- Plant in gritty, fast-draining soil, and build a low mound where clay would hold summer water around the roots
- Keep it out of lawn and flower bed sprinkler zones, where frequent water would keep its soil damp
- Mulch the root area with a thin layer of gravel, keeping it clear of the stems so the base stays dry
Through the seasons
Water a new spurge olive whenever its root ball dries a few inches down during its first summer, widening the wet area as roots spread. After that it needs only sparse summer water, and its soil must drain well whenever it gets any. The leaves stay on all year. Flowers open in late spring and red fruits follow through summer and fall, so summer is when soil checks matter. Winter rain covers the cool months on the coast and in the Central Valley. WUCOLS rates spurge olive low water on the north-central coast, in the Central Valley and on the south coast. WUCOLS has not evaluated it for South Inland, the high desert or the low desert.
In pots
Spurge olive stays small and takes clipping, which makes it a fair choice for a large container. Use a gritty, fast-draining mix and a pot with open drainage holes. In summer, check the mix 2 inches down every few days, more often in inland heat, and water when it is dry there. Soak until water runs from the holes, then empty the saucer. Move the pot to shelter before a night forecast below about 25 degrees F, the low this shrub is rated to handle.
- A year
- 6.84 gal per sq ft
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
Monthly water need by climate zone
Spurge Olive: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.15 | 0.16 | 0.31 | – | – | – |
| Feb | 0.21 | 0.26 | 0.32 | – | – | – |
| Mar | 0.35 | 0.43 | 0.46 | – | – | – |
| Apr | 0.47 | 0.61 | 0.56 | – | – | – |
| May | 0.58 | 0.83 | 0.64 | – | – | – |
| Jun | 0.64 | 0.99 | 0.69 | – | – | – |
| Jul | 0.64 | 1.07 | 0.79 | – | – | – |
| Aug | 0.6 | 0.95 | 0.74 | – | – | – |
| Sep | 0.5 | 0.72 | 0.6 | – | – | – |
| Oct | 0.35 | 0.47 | 0.46 | – | – | – |
| Nov | 0.19 | 0.22 | 0.33 | – | – | – |
| Dec | 0.12 | 0.14 | 0.26 | – | – | – |
| Year | 4.8 | 6.84 | 6.2 | – | – | – |
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 low water in the Central Valley, like spurge olive. Plants that drink alike can share one valve and one schedule.
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 spurge olive, 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 often should I water spurge olive in summer?
In July, established spurge olive in loam needs a deep watering about every 20 days in the Central Valley and about every 27 days on the south coast. Sandy soil holds less water, so waterings come closer together. Clay stretches them. Check the soil before each watering and skip one after a soaking rain.
How much water does spurge olive need per day?
In July in the Central Valley, established spurge olive needs about 0.4 gallons a day for a plant 4 feet across and about 1.7 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 spurge olive change across California?
Yes. WUCOLS rates spurge olive separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, low water 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.
Is spurge olive related to the olive tree?
No. Its narrow, leathery leaves look somewhat like an olive's, but the two plants are not related. It is not a true spurge either. Treat it as a small, dry-summer shrub rather than a fruit tree.
Can spurge olive grow under oak trees?
Yes. It is used as a tall groundcover beneath native oaks and handles dry shade well. Give a young plant its own soaks at the root ball, then let it settle into the dry ground under the canopy.
Can I use spurge olive in place of boxwood?
Yes. It takes formal clipping and can stand in for a small boxwood edging. Trim out stray or dead stems as you shape it. Keep the row on the same sparse summer soaks as a loose, unclipped plant.
Why are some spurge olive stems dying?
A stem dies off now and then even on a healthy plant, so cut it out and watch the rest. If several stems fail while the soil stays wet, check drainage before you water again. This shrub needs soil that drains well whenever it gets summer water.
How much cold can spurge olive take?
It is hardy to about 25 degrees F. In one garden it came through three nights at that low without harm. A potted plant is more exposed, so shelter it before colder nights.
Does spurge olive do well near the coast?
Yes. It suits seaside gardens and does best near the coast, in cool sun or light shade. Away from the coast, part shade suits it better than full afternoon sun.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Cneorum tricoccon, 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