WateringTimesWatering plan, $19
Quercus robur, WUCOLS IV

How often to water English oak in California

In July in the Central Valley, established English 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. English oak grows into a broad, round headed shade tree with a short, sturdy trunk and spreading limbs. It sheds its leaves through fall, though some can hang on, brown, into winter before finally dropping. This adaptable oak tolerates many soil types, though its root zone still needs attention while young.

TreeRated for 4 of 6 zones

How often to water English 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 English 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 several inches down at a young oak's root ball edge signals it needs a deep soak
  • New leaves that wilt and fail to recover by evening on a young tree point to dry soil below
  • A mature tree that browns and sheds leaves earlier than usual can follow a summer without any deep soil check
  • A white, powdery coating across the leaves can follow damp, still air rather than a watering problem, so check the soil before adjusting
  • Soil that stays wet for days near the trunk, especially in clay, can invite root and crown trouble

How to water it

  • Water a young tree across its full root ball and the soil just beyond it, not only at the trunk
  • Move drip lines or a soaker hose outward each year as the canopy and root spread widen
  • Keep irrigation away from an established trunk's base, aiming water toward the drip line and beyond
  • Apply water slowly and deeply so it reaches well down into the soil rather than pooling on the surface
  • Spread mulch under the canopy, kept clear of the trunk, to slow evaporation from the root zone

Through the seasons

Give a newly planted oak deep soakings through its first several summers while roots spread outward. Established trees generally need only occasional soil checks during the warm months, since this species adapts to many soil types once settled. It sheds its leaves through fall, sometimes holding brown foliage into winter before they finally fall. Winter rain can cover the cool months on the coast and in the valley, while South Inland trees still need summer soil checks. WUCOLS rates it moderate water on the north-central coast, in the Central Valley, on the south coast and in South Inland. WUCOLS has not evaluated it for the high desert. WUCOLS marks it as not suited to the low desert.

In pots

A young English oak can live in a large container for a couple of seasons before it needs open ground for its spreading roots. Check the mix several inches down through California's dry months rather than waiting for a visible sign. Let water run freely from the drainage holes, then empty the saucer. In winter, rainfall may keep an exposed pot damp, so check beneath the surface before adding more.

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

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.78––
Feb0.530.650.810.87––
Mar0.871.091.151.3––
Apr1.181.521.41.61––
May1.462.081.611.95––
Jun1.612.481.742.29––
Jul1.612.671.982.51––
Aug1.492.391.862.33––
Sep1.241.81.491.86––
Oct0.871.181.151.33––
Nov0.470.560.840.9––
Dec0.310.340.650.68––
Year1217.1115.518.41––

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 English 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 English 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 English 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 often should I water English oak in summer?

In July, established English oak in loam needs a deep watering about every 8 days in the Central Valley, about every 11 days on the south coast and about every 9 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 English oak need per day?

In July in the Central Valley, established English 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 English oak change across California?

Yes. WUCOLS rates English 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, moderate water in the South Coastal zone, moderate water in the South Inland zone, not evaluated in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

How should I water a newly planted English oak?

Soak the entire root ball and the adjacent soil, then let the top layers dry before the next round. Widen the watered area outward as the tree grows rather than keeping it at the trunk. An established tree needs far less attention than one still settling in.

Can English oak handle heavy or poorly drained soil?

It prefers moist, well drained loam but tolerates a range of soil types once established. Water that pools for days near the trunk still invites root trouble regardless of soil type. Improve drainage at planting time if the site holds water after rain.

Why do my oak leaves have a white powdery coating?

That coating is usually powdery mildew, which favors humid, still air rather than dry conditions. Improving airflow around the canopy helps more than changing how much you water. Check soil moisture separately before deciding whether the tree is also thirsty.

Should I keep watering an oak after its leaves drop?

Coastal and valley trees usually rest on winter rain once their leaves are down. South Inland plantings can still dry out between storms, so a soil check during dry winter spells is worthwhile. Established coastal trees rarely need help through a normal winter.

Does this guide also cover valley oak or coast live oak?

No. These ratings belong to English oak, a European species distinct from California's native oaks. Do not apply these figures to a valley oak or coast live oak growing nearby.

More plant watering guides

Peach TreesPersimmon TreesGrapevinesArborvitaeBambooCalla LiliesCannasClematis

Sources