WateringTimesWatering plan, $19
Elaeagnus angustifolia, WUCOLS IV

How often to water Russian olive in California

In July in the Central Valley, established Russian olive in loam needs a deep watering about every 20 days: about 55 gallons each time under a 10 foot canopy, about 19 gallons a week. Russian olive is a fast growing deciduous tree or large shrub, often thorny, with narrow silver-gray leaves covered in tiny scales. Small, fragrant, creamy yellow flowers in late spring are followed by silvery, olive-like fruit that birds spread. It fixes its own nitrogen and handles salt spray and dry spells, and it is invasive along California waterways.

ShrubTreeRated for 6 of 6 zones

How often to water Russian olive, month by month

Your city
Canopy width
10 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 Russian olive 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 1.5 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 under the branches, 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 canopy width

A tree with its canopy width marked across the widest branches and the circle under it shaded blue

Measure across the branches, from the tips of the outer leaves on one side to the tips on the other. A tape works, or pace it out.

Water the whole circle under the branches, shown in blue. The gallons here cover that circle.

A wider canopy means more gallons each watering, not more waterings. While the tree is young, measure again each spring.

How to tell it needs water

  • Soil dry 6 inches down beneath the canopy of a young Russian olive signals that it needs a deep soak
  • Leaves dropping early in a long, hot dry spell can indicate a dry root zone on a young or desert tree
  • Sunken, discolored patches on branches with dieback point to canker disease rather than thirst
  • Yellowing leaves over soil that stays soggy can indicate overwatering, despite its tolerance of occasional flooding
  • Suckers and seedlings appearing around the tree show it spreading, not a need for more water

How to water it

  • Water a young Russian olive over its root ball and nearby soil until roots take hold
  • Once established, soak deeply but only occasionally, letting the soil dry well in between
  • Plant in full sun in light, sandy or loamy soil, well away from creeks, ponds and wild areas
  • Skip fertilizer, since the roots fix their own nitrogen
  • Mulch the root area and pull any suckers that rise beyond it

Through the seasons

Give a new Russian olive deep soakings through its first summer while roots establish. Established trees need little added water, and deep, occasional soaks carry them through dry spells. Leaves hang on late into fall, and the fruit turns from silver to red as it ripens. WUCOLS rates Russian olive very low water on the north-central coast. It rates low water in the Central Valley, on the south coast and in South Inland. It rates moderate water in the high desert and the low desert. In California it spreads into disturbed, seasonally moist places, so remove seedlings and suckers promptly.

In pots

Russian olive grows fast and spreads by roots and seed, so a container suits only a young plant for a short time. Use a heavy pot with drainage holes and a sandy, well-drained mix. In summer heat, check a couple of inches down every few days and water when it is dry there. Let water drain fully, then empty the saucer. Handle it with gloves, since the stems can be thorny. After leaf drop, water only when the mix starts to dry.

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
0.761.52.33.00.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.761.52.33.00.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

Russian Olive: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.040.160.310.310.740.78
Feb0.050.260.320.350.930.93
Mar0.090.430.460.521.461.52
Apr0.120.610.560.641.891.95
May0.150.830.640.782.392.45
Jun0.160.990.690.922.852.79
Jul0.161.070.7913.042.85
Aug0.150.950.740.932.792.6
Sep0.120.720.60.742.142.08
Oct0.090.470.460.531.461.49
Nov0.050.220.330.360.930.96
Dec0.030.140.260.270.650.68
Year1.26.846.27.3721.2721.08

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 Russian olive. Plants that drink alike can share one valve and one schedule.

LavenderLavandula spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRosemaryRosmarinus officinalislow water, Central Valley1.07 gal/sq ft in JulyBougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyOlive TreesOlea europaea ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyFig TreesFicus carica ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyCrape MyrtleLagerstroemia spp., hybrids & cvs.low water, Central Valley1.07 gal/sq ft in JulyLantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySalviaSalvia greggii ssp., cvs. & hybridslow 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 JulyPomegranate TreesPunica granatumlow water, Central Valley1.07 gal/sq ft in JulyEucalyptusEucalyptus polyanthemoslow water, Central Valley1.07 gal/sq ft in JulyPine TreesPinus canariensislow water, Central Valley1.07 gal/sq ft in JulyJunipersJuniperus spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRussian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySagebrushArtemisia spp. (shrubby)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 Russian 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 Russian olive in summer?

In July, established Russian olive in loam needs a deep watering about every 20 days in the Central Valley, about every 27 days on the south coast and about every 22 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 Russian olive need per day?

In July in the Central Valley, established Russian olive needs about 2.7 gallons a day under a 10 foot canopy and about 11 gallons a day under a 20 foot canopy. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Does watering for Russian olive change across California?

Yes. WUCOLS rates Russian olive separately for each of the six California climate zones: very low water in the North-Central Coastal zone, low water in the Central Valley zone, low water in the South Coastal zone, low water in the South Inland zone, moderate water 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 Russian olive invasive in California?

Yes. It spreads into disturbed, seasonally moist places such as floodplains and springs, where it crowds out native cottonwoods and willows. Birds carry its seeds, and fast growth helps it take over. Avoid planting it near creeks or wild land.

Does Russian olive have thorns?

Many plants carry sharp thorns on the branches. Wear gloves and long sleeves when pruning. It tolerates pruning, but next year's flowers form on older growth.

Can Russian olive grow near the ocean?

Yes. It tolerates salt spray and a range of soils, though it prefers light, sandy or loamy ground. Full sun suits it best.

Can you overwater a Russian olive?

Yes. It tolerates occasional flooding, but soil that stays wet for long stretches harms the roots. Let the ground dry well between deep soakings once the tree is established.

Why are my Russian olive fruits turning red?

The olive-like fruits start silvery in late summer and turn red in fall. The color change is normal ripening, not a sign of stress. Birds eat them and spread the seeds.

More plant watering guides

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Sources