WateringTimesWatering plan, $19
Quercus castaneifolia, WUCOLS IV

How often to water chestnut-leaved oak in California

In July in the Central Valley, established chestnut-leaved oak 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. Chestnut-leaved oak is a large, spreading deciduous oak from the Caucasus and Iran that can reach well over 100 feet. Its long leaves emerge slightly coppery in spring, turn glossy green with shallow teeth like a chestnut's, then yellow brown in fall. It wants good light and soil that drains yet holds some moisture.

TreeRated for 3 of 6 zones

How often to water chestnut-leaved 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 chestnut-leaved 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 2 feet down under the outer canopy in a young tree's first summers signals it needs a long soak
  • Leaves browning at the margins and dropping early in late summer can indicate drought stress
  • Wilting new shoots on hot afternoons in a recently planted tree can mean the root ball has dried
  • Yellowing leaves and a thinning crown over soil that stays wet near the trunk suggest overwatering
  • White powdery coating on new leaves points to powdery mildew rather than a water shortage

How to water it

  • Soak a broad band from halfway out under the canopy to past its edge, keeping the trunk dry
  • Water a young tree 18 inches to 2 feet down, then let the upper foot dry before the next soak
  • Plant in well-drained soil that still holds some moisture, in full light with room to spread
  • Mulch a wide circle under the canopy instead of running turf to the trunk
  • Shift the watering band outward as the crown grows

Through the seasons

Water a young chestnut-leaved oak deeply through its first several summers so roots go down. An established tree needs only occasional deep soaks in long dry spells. It is fully deciduous, leafing out coppery in spring and coloring late in fall, and it is very cold hardy. Winter rain covers its dormant season in most of California. WUCOLS rates chestnut-leaved oak low water on the north-central coast, in the Central Valley and in South Inland. WUCOLS has not evaluated it for the south coast, the high desert or the low desert.

In pots

Chestnut-leaved oak is a park-sized tree and belongs in the ground. A seedling can grow on in a deep, tall container for a year or so. Check the mix 3 inches down and soak it once that layer dries, letting water run out the holes. In hot inland weather that can be every few days. After leaf drop in fall, water only to keep the root ball from drying out.

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
0.270.540.801.10.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.270.540.801.10.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

Chestnut-Leaved Oak: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.16–0.31––
Feb0.210.26–0.35––
Mar0.350.43–0.52––
Apr0.470.61–0.64––
May0.580.83–0.78––
Jun0.640.99–0.92––
Jul0.641.07–1––
Aug0.60.95–0.93––
Sep0.50.72–0.74––
Oct0.350.47–0.53––
Nov0.190.22–0.36––
Dec0.120.14–0.27––
Year4.86.84–7.37––

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 chestnut-leaved oak. Plants that drink alike can share one valve and one schedule.

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 chestnut-leaved 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 chestnut-leaved oak in summer?

In July, established chestnut-leaved oak in loam needs a deep watering about every 20 days in the Central Valley 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 chestnut-leaved oak need per day?

In July in the Central Valley, established chestnut-leaved oak 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 chestnut-leaved oak change across California?

Yes. WUCOLS rates chestnut-leaved oak separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, not evaluated in the South Coastal zone, low 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.

How big does chestnut-leaved oak get?

It can grow into a large, spreading tree up to about 35 meters, over 100 feet. It is best suited to large gardens and parks. Plant it far from buildings and pipes.

Why are my oak leaves white and dusty?

That is likely powdery mildew, which this oak can get. It is a leaf disease, not a sign of thirst. Avoid sprinklers that wet the foliage.

When does chestnut-leaved oak color in fall?

It colors late in autumn, in yellow and brown. Leaves then drop for winter. Spring growth comes out slightly coppery.

What pests affect chestnut-leaved oak?

Aphids, caterpillars, leaf miners and gall wasps can feed on it. It can also get honey fungus, a root disease.

Can chestnut-leaved oak grow in a lawn?

Frequent turf watering keeps the trunk area wet, which oaks dislike. Use a wide ring of mulch instead of grass. Give the tree its own deep soaks.

More plant watering guides

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Sources