WateringTimesWatering plan, $19
Euphorbia characias wulfenii, WUCOLS IV

How often to water Mediterranean spurge in California

In July in the Central Valley, established Mediterranean spurge in loam needs a deep watering about every 14 days: about 1.5 gallons each time for a plant 2 feet across, about 0.8 gallons a week. Mediterranean spurge is an upright, evergreen subshrub with blue-green leaves and large, rounded heads of chartreuse bracts from early spring into early summer. It wants sun and sharp drainage, and established plants get by on little water except in the low desert. Its milky sap irritates skin and eyes, so wear gloves when cutting it.

PerennialSucculentRated for 5 of 6 zones

How often to water Mediterranean spurge, month by month

Your city
Plant width
2 ft
Your soil

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.

Every month, on your water days. The personal plan prints this for Mediterranean spurge and the rest of your yard, on the days your water supplier allows.Get the plan for $19

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.

Which soil do you have?

Dig down a few inches, take a handful of moist soil and squeeze it.

  • Sandy: gritty, falls apart when you open your hand, will not form a ball.
  • Loam: forms a soft ball that crumbles when you poke it.
  • Clay: forms a firm, sticky ball and squeezes out into a ribbon between thumb and finger.

Still not sure? Pick loam. Most garden beds sit between sand and clay.

How to measure plant width

A shrub with its width marked from one side to the other and the circle under it shaded blue

Measure across the plant, from the tips of the leaves on one side to the tips on the other.

Water the whole area the plant covers, shown in blue. The gallons here cover that area.

A wider plant means more gallons each watering, not more waterings. While it is young, measure again each spring.

How to tell it needs water

  • Soil dry 4 inches down at the base means Mediterranean spurge can take a deep soak in summer heat
  • Leaves hanging limp in late afternoon heat over dry soil can show the plant is thirsty
  • Stems that turn soft and black at the base in wet soil point to rot from poor drainage
  • Flowered stems browning in summer are normal, and they can be cut to the ground
  • Seedlings sprouting all around the plant reflect its prolific self-sowing, not too much water

How to water it

  • Water Mediterranean spurge at the soil around the base, keeping water off the crown
  • Soak about 8 to 10 inches deep, then let the soil dry well before the next soak
  • Plant in full sun in well-drained, light soil, using a slope or raised bed in heavy clay
  • Use gravel mulch rather than bark so the base stays dry
  • Water a slightly wider area as the clump fills out

Through the seasons

Give a new Mediterranean spurge regular water through its first spring and summer, then let the soil dry deeply between soakings. Established plants stay evergreen and flower from early spring into early summer. Cut flowered stems to the ground in late summer or fall to tidy the clump. Irrigation matters most in summer heat. WUCOLS rates Mediterranean spurge very low water on the south coast. It rates low water on the north-central coast, in the Central Valley and in South Inland, and moderate water in the low desert. WUCOLS has not evaluated it for the high desert.

In pots

Mediterranean spurge suits a large pot of gritty, fast-draining mix in full sun. In summer heat, check the mix 2 inches down every few days and water only when it is dry. Let the excess drain away, then empty the saucer, since roots in wet mix can rot. Wear gloves when you trim it, because the milky sap irritates skin and eyes. In winter, water sparingly, and only after the mix has dried well.

1 Your climate zone six WUCOLS zones, each from its own reference city
1.07gal per sq ft in JulyLow water use in the Central Valley zone
A year
6.84 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.711.42.12.90.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.711.42.12.90.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

Mediterranean Spurge: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.160.080.31–0.78
Feb0.210.260.080.35–0.93
Mar0.350.430.110.52–1.52
Apr0.470.610.140.64–1.95
May0.580.830.160.78–2.45
Jun0.640.990.170.92–2.79
Jul0.641.070.21–2.85
Aug0.60.950.190.93–2.6
Sep0.50.720.150.74–2.08
Oct0.350.470.110.53–1.49
Nov0.190.220.080.36–0.96
Dec0.120.140.070.27–0.68
Year4.86.841.557.37–21.08

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 Mediterranean spurge. Plants that drink alike can share one valve and one schedule.

AgapanthusAgapanthus orientalislow water, Central Valley1.07 gal/sq ft in JulyGeraniumsPelargonium x hortorum and cvs.low water, Central Valley1.07 gal/sq ft in JulySalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in JulyIrisesIris germanicalow water, Central Valley1.07 gal/sq ft in JulyAloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRussian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyYarrowAchillea millefolium (non-native hybrids)low water, Central Valley1.07 gal/sq ft in JulyMountain AlyssumAlyssum montanumlow water, Central Valley1.07 gal/sq ft in JulySilver SageSalvia argentealow water, Central Valley1.07 gal/sq ft in JulyPurple MulleinVerbascum phoeniceumlow water, Central Valley1.07 gal/sq ft in JulySilvery YarrowAchillea clavennaelow water, Central Valley1.07 gal/sq ft in JulyFern Leaf YarrowAchillea filipendulinalow water, Central Valley1.07 gal/sq ft in JulyCalifornia Native YarrowAchillea millefolium (CA native cultivars)low water, Central Valley1.07 gal/sq ft in JulyWoolly YarrowAchillea tomentosalow water, Central Valley1.07 gal/sq ft in JulyPerennial HollyhockAlcea rosea cvs.low water, Central Valley1.07 gal/sq ft in July
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes Mediterranean 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 often should I water Mediterranean spurge in summer?

In July, established Mediterranean spurge in loam needs a deep watering about every 14 days in the Central Valley, about once a month or less on the south coast and about every 14 days in the South Inland zone. 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 Mediterranean spurge need per day?

In July in the Central Valley, established Mediterranean spurge needs about 0.1 gallons a day for a plant 2 feet across and about 0.4 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 Mediterranean spurge change across California?

Yes. WUCOLS rates Mediterranean spurge separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, very low water in the South Coastal zone, low water in the South Inland zone, not evaluated in the High and Intermediate Desert zone, moderate water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Is Mediterranean spurge sap dangerous?

The milky sap irritates skin and eyes, and the plant is harmful if eaten. Wear gloves and eye protection when cutting it, and wash off any sap right away.

When should I cut back Mediterranean spurge?

Once a stem has finished flowering, remove it at the base, ideally in late summer or autumn. Wear gloves, since sap flows from every cut.

Does Mediterranean spurge spread?

It self-sows prolifically and may become invasive. Remove spent flower heads before seeds ripen, and pull seedlings while they are small.

Can Mediterranean spurge take shade?

It does best in sun, though afternoon shade suits it in hot inland and desert gardens. Shade slows drying, so a shaded plant needs water less often.

Can you overwater Mediterranean spurge?

Yes. It needs good drainage, and roots kept wet can rot. Let the soil dry well between soakings, especially in winter.

More plant watering guides

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Sources