WateringTimesWatering plan, $19
Quercus alba, WUCOLS IV

How often to water eastern white oak in California

In July in the Central Valley, established eastern white oak in loam needs a deep watering about every 8 days: about 55 gallons each time under a 10 foot canopy, about 47 gallons a week. Eastern white oak is a slow-growing, long-lived deciduous oak from the eastern United States. It has rounded, fingerlike leaf lobes and ash-gray, scaly bark. Its leaves turn dark red to brown in fall. It grows best in deep, moist, well-drained soil, and in California's dry summers it needs deep soakings rather than drought.

TreeRated for 2 of 6 zones

How often to water eastern white oak, 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 eastern white oak 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 at the edge of a young white oak's root ball signals that it needs a deep soak
  • Leaf edges scorching brown in late summer can indicate the root zone dried out during a heat spell
  • Yellow leaves with green veins point to iron chlorosis from alkaline soil, which more water will not cure
  • A wet, sour-smelling root crown or mushrooms at the trunk base warn of root rot from waterlogged soil
  • Brown blotches on spring leaves after wet weather can point to anthracnose rather than thirst

How to water it

  • Water a young oak over its root ball and just beyond, widening the ring as roots spread
  • Soak the soil 18 inches to 2 feet deep, then let the top several inches dry before the next soak
  • Keep emitters and sprinkler spray off the trunk, placing water under the outer canopy as the tree matures
  • Plant in deep, well-drained, slightly acidic loam, avoiding wet sites and compacted ground
  • Spread wood chip mulch over the root zone and keep foot and vehicle traffic off it to prevent compaction

Through the seasons

A newly planted eastern white oak needs deep soakings through its first few summers while its taproot and side roots spread. Established trees need fewer, deeper soakings through the dry season, since this oak comes from a climate with summer rain. Leaves emerge in spring, turn dark red to brown in fall, and drop for winter. Winter rain covers the dormant months on the north-central coast and in the Central Valley. On the north-central coast and in the Central Valley, WUCOLS gives eastern white oak a moderate water rating. The south coast, South Inland, the high desert and the low desert have not been evaluated.

In pots

Eastern white oak forms a deep taproot early and is hard to move later, so a pot suits only a seedling. Use a deep, narrow container that leaves room for the taproot. Check the mix 2 to 3 inches down every few days in summer and water until it drains through, then empty the saucer. Plant it out young, before the taproot coils. In winter the leafless seedling needs only enough water to keep the mix from drying out.

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

Eastern White Oak: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.4––––
Feb0.530.65––––
Mar0.871.09––––
Apr1.181.52––––
May1.462.08––––
Jun1.612.48––––
Jul1.612.67––––
Aug1.492.39––––
Sep1.241.8––––
Oct0.871.18––––
Nov0.470.56––––
Dec0.310.34––––
Year1217.11––––

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 eastern white oak. Plants that drink alike can share one valve and one schedule.

Citrus TreesCitrus spp.moderate water, Central Valley2.67 gal/sq ft in JulyJapanese MapleAcer palmatummoderate water, Central Valley2.67 gal/sq ft in JulyAvocado TreesPersea americanamoderate water, Central Valley2.67 gal/sq ft in JulyMagnolia TreesMagnolia grandiflora ssp. & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyPalm TreesSyagrus romanzoffiana (Arecastrum romanzoffianum)moderate water, Central Valley2.67 gal/sq ft in JulyApple TreesMalus spp. (edible) e.g, 'Anna' (low chill variety for low desert)moderate water, Central Valley2.67 gal/sq ft in JulyPeach TreesPrunus spp. ediblemoderate water, Central Valley2.67 gal/sq ft in JulyPersimmon TreesDiospyros kakimoderate water, Central Valley2.67 gal/sq ft in JulyAmur MapleAcer ginnalamoderate water, Central Valley2.67 gal/sq ft in JulyFernleaf MapleAcer japonicummoderate water, Central Valley2.67 gal/sq ft in JulyBox ElderAcer negundomoderate water, Central Valley2.67 gal/sq ft in JulyNorway MapleAcer platanoidesmoderate water, Central Valley2.67 gal/sq ft in JulyRed MapleAcer rubrummoderate water, Central Valley2.67 gal/sq ft in JulyChinese MapleAcer truncatummoderate water, Central Valley2.67 gal/sq ft in JulyRed BuckeyeAesculus paviamoderate water, Central Valley2.67 gal/sq ft in JulyRed HorsechestnutAesculus x carneamoderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

Rated lower than eastern white oak in the Central Valley. Worth a look for a new bed or a lawn replacement.

Olive 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 JulyAloeAloe 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 JulyTexas Red OakQuercus buckleyilow water, Central Valley1.07 gal/sq ft in JulyPortuguese OakQuercus faginealow water, Central Valley1.07 gal/sq ft in JulySoapbark TreeQuillaja saponarialow water, Central Valley1.07 gal/sq ft in JulyNecklace TreeSophora affinislow water, Central Valley1.07 gal/sq ft in JulyBailey AcaciaAcacia baileyanalow water, Central Valley1.07 gal/sq ft in JulySilver WattleAcacia dealbatalow water, Central Valley1.07 gal/sq ft in JulyGreen WattleAcacia decurrenslow water, Central Valley1.07 gal/sq ft in JulySydney Golden WattleAcacia longifolialow 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 eastern white oak, 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 eastern white oak need per day?

In July in the Central Valley, established eastern white oak needs about 6.8 gallons a day under a 10 foot canopy and about 27 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 eastern white oak change across California?

Yes. WUCOLS rates eastern white oak separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, moderate water 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.

Should I water white oak like a native California oak?

No. Native California oaks are adapted to dry summers, while this eastern species comes from a summer-rain climate. Give it deep soakings through the dry season, placed away from the trunk. Let the root crown dry between soakings.

Why are my white oak leaves yellow with green veins?

That pattern is iron chlorosis, which shows up when soil pH is too high. White oak prefers slightly acidic soil, and extra water will not fix it. Test the soil and correct the pH or iron supply instead.

Can I transplant an eastern white oak?

Only while it is small. Its deep taproot makes older trees difficult to move. Keep a transplanted young oak's root ball moist through its first summer.

How big does eastern white oak get?

It grows slowly but can reach 60 feet or more tall and wide in landscapes, and far taller in eastern forests. Plant it well away from structures and pavement. A tree that size needs water spread under its whole canopy.

Are white oak acorns safe?

The acorns are fairly low in tannins and can be eaten by people after the tannins are leached or boiled out. The tree is toxic to horses, so keep it out of horse pastures.

More plant watering guides

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Sources