WateringTimesWatering plan, $19
Euphorbia x martinii and cvs., WUCOLS IV

How often to water Martin's spurge in California

In July in the Central Valley, established Martin's spurge in loam needs a deep watering about every 5 days: about 1.5 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Martin's spurge is a dwarf evergreen hybrid euphorbia, 1 to 3 feet tall, found wild in southern France. Narrow gray-green leaves on reddish stems take a burgundy tint, strongest on new growth. In spring dense clusters of chartreuse bracts with dark red eyes cover it. It tolerates rocky, dry soil once established, and its milky sap is toxic and irritating.

PerennialSucculentRated for 4 of 6 zones

How often to water Martin's 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 Martin's 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

  • Ground dry 3 inches down beside the clump in summer tells you Martin's spurge can take a drink
  • Leaves drooping and folding along the stems on a hot afternoon can indicate thirst
  • Lower leaves yellowing and falling in a long hot spell can follow a dry root zone
  • Stems collapsing at the base in soggy soil point to rot from overwatering

How to water it

  • Water the soil around the clump with drip or a slow hose, keeping the stems dry
  • Give a thorough soak, then let the top few inches dry before the next one
  • Plant in full sun to part shade in well-drained soil, even rocky ground
  • Cut flowered stems back to about 6 inches after bloom, wearing gloves
  • Leave space around each plant so air moves through the foliage

Through the seasons

Water a new plant regularly until it is growing well, then let the soil dry more between soaks. Established clumps take drought once settled. It is evergreen, with the strongest burgundy color on new spring growth and chartreuse bracts in spring. Pruning right after bloom keeps it bushy. On the north-central coast, WUCOLS rates Martin's spurge low water. The Central Valley, the south coast and South Inland carry a moderate water rating. WUCOLS has not evaluated it for the high desert or the low desert.

In pots

Martin's spurge makes a tidy, colorful container plant in a pot of gritty, well-drained mix. Water when the mix is dry a couple of inches down, and let every bit of excess run out. A small pot in full sun may need water every few days in summer. Never leave it sitting in water. Trim spent stems after bloom with gloves on. In winter, water only when the mix is dry.

1 Your climate zone six WUCOLS zones, each from its own reference city
2.67gal per sq ft in JulyModerate water use in the Central Valley zone
A year
17.11 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.671.32.02.70.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.671.32.02.70.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Martin's Spurge: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.40.780.78––
Feb0.210.650.810.87––
Mar0.351.091.151.3––
Apr0.471.521.41.61––
May0.582.081.611.95––
Jun0.642.481.742.29––
Jul0.642.671.982.51––
Aug0.62.391.862.33––
Sep0.51.81.491.86––
Oct0.351.181.151.33––
Nov0.190.560.840.9––
Dec0.120.340.650.68––
Year4.817.1115.518.41––

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 Martin's spurge. Plants that drink alike can share one valve and one schedule.

DahliasDahlia spp.moderate water, Central Valley2.67 gal/sq ft in JulyFernsNephrolepis cordifolia (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in JulyDayliliesHemerocallis spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyBegoniasBegonia & ssp. & cvs. (shade in the desert)moderate water, Central Valley2.67 gal/sq ft in JulyCalla LiliesZantedeschia aethiopica SHADE IN DESERTmoderate water, Central Valley2.67 gal/sq ft in JulySageSalvia officinalis and cvs.moderate water, Central Valley2.67 gal/sq ft in JulyBicolor MonkshoodAconitum cammarummoderate water, Central Valley2.67 gal/sq ft in JulyGarden MonkshoodAconitum napellusmoderate water, Central Valley2.67 gal/sq ft in JulyCarpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in JulySnowdrop WindflowerAnemone sylvestrismoderate water, Central Valley2.67 gal/sq ft in JulyMountain SandwortArenaria montanamoderate water, Central Valley2.67 gal/sq ft in JulySwamp MilkweedAsclepias incarnatamoderate water, Central Valley2.67 gal/sq ft in JulyOrange MilkweedAsclepias tuberosamoderate water, Central Valley2.67 gal/sq ft in JulyGreater MasterwortAstrantia majormoderate water, Central Valley2.67 gal/sq ft in JulyHardy BegoniaBegonia grandismoderate water, Central Valley2.67 gal/sq ft in JulyWax BegoniaBegonia semperflorensmoderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

Rated lower than Martin's spurge in the Central Valley. Worth a look for a new bed or a lawn replacement.

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 Martin'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 often should I water Martin's spurge in summer?

In July, established Martin's spurge in loam needs a deep watering about every 5 days in the Central Valley, about every 7 days on the south coast and about every 6 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 Martin's spurge need per day?

In July in the Central Valley, established Martin's spurge needs about 0.3 gallons a day for a plant 2 feet across and about 1.1 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 Martin's spurge change across California?

Yes. WUCOLS rates Martin's spurge separately for each of the six California climate zones: low water in the North-Central Coastal zone, moderate water in the Central Valley zone, moderate water in the South Coastal zone, moderate water 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 Martin's spurge sap dangerous?

Yes, its milky sap is toxic and can irritate skin and eyes. Always wear gloves when cutting it. Keep it away from children and pets.

When should I prune Martin's spurge?

Cut it back to about 6 inches in mid-spring, right after it flowers. That keeps it bushy. Wear gloves and eye protection.

Does Martin's spurge reseed?

No, it does not reseed. Propagate it by cuttings if you want more plants. That also keeps it from spreading.

Why are the leaves red on my euphorbia?

New growth carries a burgundy tint that fades as leaves age. Red stems are normal for this plant. It is not a sign of stress.

Can Martin's spurge take drought?

Once established, it tolerates rocky, dry soil and drought. Young plants need regular water. Check the soil a few inches down.

More plant watering guides

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Sources