WateringTimesWatering plan, $19
Quercus macrocarpa, WUCOLS IV

How often to water burr oak in California

In July in the Central Valley, established burr 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. Burr oak, also spelled bur oak, is a large, long-lived white oak from central and eastern North America. It has deeply lobed, leathery leaves and gray, deeply furrowed bark. Its big acorns sit in cups edged with a shaggy fringe. It tolerates alkaline soil better than most oaks, and established trees tolerate dry spells.

TreeRated for 4 of 6 zones

How often to water burr 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 burr 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

  • Dry soil 6 inches down at the root ball edge of a young burr oak calls for a deep soak
  • Leaves browning at the edges in a young tree's first summers can follow a dry root ball
  • Leaves fading to brown or gold in autumn is normal fall color, not drought
  • Yellowing leaves in summer on soil kept wet by lawn sprinklers suggest the roots are getting too much water
  • A young tree that sulks after planting is reacting to its disturbed taproot, so keep the root ball evenly moist

How to water it

  • Water a young burr oak over its root ball and the soil just beyond, keeping the trunk dry
  • Soak deeply enough to reach 2 feet down, since the taproot runs deep, then let the upper soil dry
  • Plant a small tree rather than a large one, because the long taproot makes transplanting hard
  • Mulch a wide ring with wood chips or the tree's own leaves, clear of the trunk
  • Widen the watered area over the years toward the edge of a canopy that can reach 70 to 80 feet

Through the seasons

Water a new burr oak deeply through its first few summers while the taproot and spreading roots establish. Established trees tolerate dry spells and alkaline soil, but long, hot summers still call for occasional deep soakings. Leaves emerge in spring, acorns mature in one season, and fall color runs from brown to gold. Rain usually covers the bare months on the coast and in the Central Valley. Burr oak carries a moderate water rating in the high desert, on the south coast, in the Central Valley and on the north-central coast. South Inland and the low desert remain not evaluated by WUCOLS.

In pots

Burr oak forms a long taproot early, so a pot is only a brief start for a seedling. Use a tall, deep container with drainage holes. Check 2 to 3 inches down every few days in summer heat, water when dry, and pour off the saucer. In winter the bare seedling needs only occasional water. Plant it out while small, since larger trees are difficult to transplant.

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
0.761.52.33.00.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.761.52.33.00.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.78–0.74–
Feb0.530.650.81–0.93–
Mar0.871.091.15–1.46–
Apr1.181.521.4–1.89–
May1.462.081.61–2.39–
Jun1.612.481.74–2.85–
Jul1.612.671.98–3.04–
Aug1.492.391.86–2.79–
Sep1.241.81.49–2.14–
Oct0.871.181.15–1.46–
Nov0.470.560.84–0.93–
Dec0.310.340.65–0.65–
Year1217.1115.5–21.27–

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 burr 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 burr 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 burr 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 burr oak in summer?

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

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

Yes. WUCOLS rates burr 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, not evaluated in the South Inland zone, moderate water 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.

Can I transplant a burr oak?

Only while it is young. Its long taproot makes larger trees difficult to move. A transplanted oak needs steady deep watering for several summers.

Why are burr oak acorns so big?

Burr oak bears large acorns in a cup that covers a third or more of the nut, with a fringed edge. They mature in one season. Acorn size has nothing to do with watering.

Does burr oak grow in alkaline soil?

Yes. Alkaline ground suits it better than it suits most oaks. Good drainage still matters, so avoid low spots where water stands.

How big does burr oak get?

It can reach 70 to 80 feet tall and as wide, with strong branches and an open, rounded crown. Give it room, and plan its watering for a root zone wider than the canopy.

Can you overwater burr oak?

Yes. Frequent lawn watering keeps its roots wet, which an established oak does not need. Water deeply and let the soil dry between soakings.

More plant watering guides

FernsDayliliesBegoniasIvyApple TreesPeach TreesPersimmon TreesGrapevines

Sources