How often to water Seguier's spurge in California
In July on the north-central coast, established Seguier's spurge in loam needs a deep watering about every 22 days: about 1.5 gallons each time for a plant 2 feet across, about 0.5 gallons a week. Seguier's spurge, Euphorbia seguieriana subspecies niciciana, is a clump-forming perennial native from the Balkan Peninsula to Pakistan. Narrow, spreading blue-green leaves fill out a bushy clump, topped by lime-green flower heads in late spring. It grows about 18 inches tall and wide. Once rooted in, it resists drought and wants light soil that drains fast.
How often to water Seguier's spurge, 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 foot 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 inches down beside a young clump in its first summer means it is time for a soak
- Limp, drooping stems on a young plant during a hot dry spell show its small root zone has dried out
- Thinner foliage in winter is normal for this semi-evergreen perennial and does not mean it needs water
- Stems that wilt and yellow while the soil around the crown stays soggy point to root rot, not thirst
How to water it
- Water at the base of a new clump during dry spells in its first two growing seasons
- Plant in full sun in light sandy, loamy or chalky soil that drains fast
- Once it is established, let the soil dry well down between soakings
- Keep it out of beds that stay moist under lawn sprinklers, since wet soil leads to root rot
- Widen the watered spot a little as the clump fills out over the years
Through the seasons
Water a new Seguier's spurge through dry spells in its first two growing seasons, while its roots settle. After that it is drought resistant and needs water only in long dry stretches. It is semi-evergreen and flowers from late spring. In late summer or fall, cut the flowered shoots down to ground level. WUCOLS rates Seguier's spurge low water on the north-central coast, where winter rain covers the cool months. WUCOLS has not evaluated it for the Central Valley, the south coast, South Inland, the high desert or the low desert. In those regions, water by soil checks and plant cues.
In pots
Seguier's spurge suits a sunny patio container, and its compact size fits a medium pot. Mix about three parts potting mix with one part grit, and use a pot with a drainage hole. From spring to fall, check the mix 2 inches down every few days and keep it just damp, never soggy. A small pot on hot paving dries fast in a heat wave, so check it more often then. Water until it drains, then empty the saucer. In winter, let the mix dry more between waterings.
- A year
- no figure
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
WUCOLS lists Seguier's Spurge as not evaluated for the Central Valley zone, so no monthly figure is computed here.
Monthly water need by climate zone
Seguier's Spurge: 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 | – | – | – | – | – |
| Feb | 0.21 | – | – | – | – | – |
| Mar | 0.35 | – | – | – | – | – |
| Apr | 0.47 | – | – | – | – | – |
| May | 0.58 | – | – | – | – | – |
| Jun | 0.64 | – | – | – | – | – |
| Jul | 0.64 | – | – | – | – | – |
| Aug | 0.6 | – | – | – | – | – |
| Sep | 0.5 | – | – | – | – | – |
| Oct | 0.35 | – | – | – | – | – |
| Nov | 0.19 | – | – | – | – | – |
| Dec | 0.12 | – | – | – | – | – |
| Year | 4.8 | – | – | – | – | – |
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 not evaluated in the Central Valley, like Seguier's spurge. Plants that drink alike can share one valve and one schedule.
Lilyleaf LadybellsAdenophora liliifolianot rated, Central Valleyno Central Valley rating
ArnicaArnica montananot rated, Central Valleyno Central Valley rating
Frilly BergeniaBergenia ciliatanot rated, Central Valleyno Central Valley rating
Cabbage on a StickBrighamia insignisnot rated, Central Valleyno Central Valley rating
Basket PlantCallisia fragransnot rated, Central Valleyno Central Valley rating
Forest SedgeCarex sylvaticanot rated, Central Valleyno Central Valley rating
Umbrella DracaenaDianella ensifolianot rated, Central Valleyno Central Valley rating
Rusty FoxgloveDigitalis ferrugineanot rated, Central Valleyno Central Valley rating
Big-Flowered FoxgloveDigitalis grandifloranot rated, Central Valleyno Central Valley rating
Woolly FoxgloveDigitalis lanatanot rated, Central Valleyno Central Valley rating
Sunset FoxgloveDigitalis obscuranot rated, Central Valleyno Central Valley rating
Male FernDryopteris filix-masnot rated, Central Valleyno Central Valley rating
Alpine Sea HollyEryngium alpinumnot rated, Central Valleyno Central Valley rating
Purple SpurgeEuphorbia dulcisnot rated, Central Valleyno Central Valley rating
Queen of the MeadowFilipendula ulmarianot rated, Central Valleyno Central Valley rating
DropwortFilipendula vulgaris (Filipendula hexapetala)not rated, Central Valleyno Central Valley ratingTurn this into minutes on your water days
Every city page has a calculator that takes Seguier's spurge, 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 Seguier's spurge need per day?
In July on the north-central coast, established Seguier's spurge needs about 0.1 gallons a day for a plant 2 feet across and about 0.3 gallons a day for a plant 4 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 Seguier's spurge change across California?
Yes. WUCOLS rates Seguier's spurge separately for each of the six California climate zones: low water in the North-Central Coastal zone, not evaluated 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.
Is Seguier's spurge poisonous?
Yes. Its milky sap irritates skin and eyes, and the plant is harmful if eaten. Wear gloves when you cut it back or take cuttings, and keep it away from children and pets.
When should I cut back Seguier's spurge?
Cut the flowering shoots back to ground level in late summer or fall, once the flower heads are spent. That keeps the clump tidy. Wear gloves for the job.
How do I propagate Seguier's spurge?
Take basal cuttings in spring or early summer, using shoots from the base of the clump. Wear gloves while you work, since the sap irritates skin.
How cold can Seguier's spurge handle?
It is rated hardy to roughly 5 to 14 degrees F, which covers most places in the UK even in severe winters. In winter, the more common trouble is root rot in wet soil. Keep winter watering light.
What soil does Seguier's spurge need?
It grows best in light, well-drained soil in full sun. Sandy, loamy and chalky soils all suit it, whether acid, neutral or alkaline. Heavy clay that stays wet is a poor fit.
Does Seguier's spurge get pests or diseases?
It is generally free of pests and diseases. The main problem is root rot in soil that stays wet. Plant it where the soil drains fast, and let it dry between waterings.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Euphorbia seguieriana niciciana, 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