WateringTimesWatering plan, $19
Quercus bicolor, WUCOLS IV

How often to water swamp white oak in California

In July in the Central Valley, established swamp 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. Swamp white oak is a broad, deciduous shade tree of eastern North American bottomlands, swamps and stream banks. Its leaves are dark green above and silvery white beneath, and its acorns hang on long stalks. It tolerates spring flooding and fairly dry summers, but it wants acidic soil and turns yellow in alkaline ground.

TreeRated for 2 of 6 zones

How often to water swamp 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 swamp 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

  • Dry soil 6 inches down at the canopy edge means a young swamp white oak needs a deep soak
  • Leaves browning at the margins in a young tree's first summers can follow a dry root ball
  • Yellow leaves with green veins point to chlorosis from alkaline soil, not a water problem
  • Leaves yellowing in summer under constant lawn watering suggest the roots are getting more water than they need
  • Thin growth on compacted soil reflects the tree's sensitivity to compaction rather than thirst

How to water it

  • Water a young swamp white oak over its root ball and beyond with a slow soaker
  • Soak the soil 18 to 24 inches deep, then let the upper several inches dry
  • Plant in full sun in moist, acidic soil, and avoid alkaline sites where leaves turn yellow
  • Protect the root zone from foot traffic and vehicles, since the tree is sensitive to compaction
  • Widen the mulched, watered area over the years toward a 50 to 60 foot canopy

Through the seasons

Water a new swamp white oak deeply through its first few summers while roots spread. Once established it tolerates fairly dry summers, though deep soakings help in long, hot spells. Leaves emerge in spring and drop in fall, and good acorn crops come only every 3 to 5 years. On the north-central coast and in the Central Valley, rainy winters usually keep the dormant tree supplied. WUCOLS gives swamp white oak a moderate water rating in both of those zones, the north-central coast and the Central Valley. The south coast, South Inland, the high desert and the low desert have not been evaluated.

In pots

Swamp white oak becomes a 50 to 60 foot tree, so keep a seedling in a pot only until it can be planted. Use a tall container with drainage holes and an acidic, moisture-holding mix. In summer, check the top 2 inches every few days and water when dry. This oak tolerates wet roots better than most, but still empty a saucer that stays full. In winter the bare seedling needs only occasional water.

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

Swamp 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 swamp 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 swamp 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 swamp 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 swamp white oak need per day?

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

Yes. WUCOLS rates swamp 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.

Can swamp white oak grow in wet soil?

Yes. It grows naturally in swamps, floodplains and along streams, and it tolerates spring flooding. It also handles fairly dry summers once established.

Why are my swamp white oak leaves yellow?

Yellow leaves with green veins usually mean chlorosis from alkaline soil. This oak needs acidic soil, and extra water will not fix the color.

How do I recognize swamp white oak?

Look for leaves that are dark green above and silvery white below, branches with peeling bark and acorns on long stalks. Those traits set it apart from other oaks.

Is swamp white oak sensitive to anything?

It is sensitive to soil compaction, salt and air pollution. Keep cars and heavy foot traffic off the root zone, and keep road salt runoff away.

Can you overwater swamp white oak?

It tolerates wet soil better than most oaks, especially in spring. Even so, let the upper soil dry between summer soakings rather than keeping it constantly saturated.

More plant watering guides

Magnolia TreesPalm TreesSago PalmStar JasmineHoneysuckleFernsDayliliesBegonias

Sources