WateringTimesWatering plan, $19
Quercus variabilis, WUCOLS IV

How often to water Chinese cork oak in California

In July in the Central Valley, established Chinese cork 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. Chinese cork oak is a large deciduous oak from East Asia with thick, corky, ridged bark that is harvested for cork in its homeland. Its narrow leaves are white and downy underneath and edged with bristle-tipped teeth. It grows slowly, needs full sun and well-drained soil, and tolerates occasional dry spells once established.

TreeRated for 1 of 6 zones

How often to water Chinese cork 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 Chinese cork 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

  • A young Chinese cork oak is due for a deep soak when the root ball edge is dry 6 inches down
  • Leaves browning or curling in a young tree's first hot summer can follow a dry root zone
  • Young trees holding dead leaves into winter is normal for this oak
  • Yellowing leaves in soil that stays soggy suggest poor drainage around the roots
  • Thick, spongy bark is the tree's natural cork, not a disease

How to water it

  • Water a young Chinese cork oak around the root ball and beyond, keeping the trunk dry
  • Run a slow soak until moisture reaches 18 inches, and hold off until the top several inches have dried
  • Plant in full sun in clay, loam or sand that drains well
  • Mulch a wide ring with wood chips, clear of the corky trunk
  • Move irrigation outward slowly as the tree grows toward a very wide canopy

Through the seasons

Water a new Chinese cork oak deeply through its first few summers while roots spread. Established trees tolerate occasional dry spells, though long hot summers still call for deep soakings. Leaves turn and drop in fall, though young trees often hold them into winter. Acorns take two years to mature. Central Valley rain generally carries the leafless tree from late fall into spring. Its one WUCOLS rating is moderate water, for the Central Valley. It has not been evaluated for the north-central coast, the south coast, South Inland, the high desert or the low desert.

In pots

Chinese cork oak grows into a very large tree, so a container only suits a young seedling. Choose a tall pot that drains freely, filled with a gritty, loamy mix. Check 2 to 3 inches down every few days in summer heat and water when dry. Empty the saucer afterward. In winter, a young tree may hold its dead leaves, and it needs only occasional water while dormant.

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

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan–0.4––––
Feb–0.65––––
Mar–1.09––––
Apr–1.52––––
May–2.08––––
Jun–2.48––––
Jul–2.67––––
Aug–2.39––––
Sep–1.8––––
Oct–1.18––––
Nov–0.56––––
Dec–0.34––––
Year–17.11––––

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 Chinese cork 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 Chinese cork 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 Chinese cork 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 Chinese cork oak need per day?

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

Yes. WUCOLS rates Chinese cork oak separately for each of the six California climate zones: not evaluated 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.

Is the bark of Chinese cork oak real cork?

Yes. Its thick, corky, ridged bark is harvested for cork in Asia. Avoid wounding it with string trimmers, and keep mulch and water off the trunk.

Why does my young cork oak keep its dead leaves?

Young trees often hold their dry leaves into winter. This is normal and not a sign of drought.

Are Chinese cork oak acorns toxic?

The acorns and leaves can cause stomach upset if eaten, so keep children and pets from chewing them. Rake up fallen acorns near play areas.

How big does Chinese cork oak get?

It grows slowly to about 60 to 80 feet tall and nearly as wide. Plan its watering for a root zone that keeps widening for decades.

Can you overwater Chinese cork oak?

Yes. It needs good drainage, and constantly wet soil can harm the roots. Water deeply, then let the soil dry between soakings.

More plant watering guides

ArborvitaeBambooCalla LiliesCannasClematisLilacsSpireaButterfly Bush

Sources