WateringTimesWatering plan, $19
Quercus x Heritage, WUCOLS IV

How often to water Heritage oak in California

In July in the high desert, established Heritage oak in loam needs a deep watering about every 7 days: about 55 gallons each time under a 10 foot canopy, about 54 gallons a week. Heritage oak is a hybrid of English oak and bur oak, sold as the cultivar 'Clemons'. It is a vigorous deciduous tree with a straight central leader, a pyramidal crown and glossy, leathery leaves that resist powdery mildew. WUCOLS rates it only for the two desert zones, where it counts as a moderate water tree.

TreeRated for 2 of 6 zones

How often to water Heritage 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 Heritage 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 Heritage oak needs a deep soak once the soil beside its root ball has dried 4 to 6 inches down
  • Leaves curling, scorching at the edges or dropping early in desert heat can point to a dry root zone
  • Wilting over soil that stays soggy for days points to poor drainage and possible root rot
  • Leaf edges browned by hot, dry wind can show scorch even over moist soil, so check before you water
  • Shoots rising from below the graft come from the rootstock, not the hybrid, and should be cut off

How to water it

  • Water a young tree over the root ball and a wide ring beyond it, widening the ring as the canopy grows
  • Through desert summers, soak slowly so water reaches 18 inches or more, then let the top several inches dry
  • Move drip lines or bubblers out under the canopy edge of an older tree, keeping the trunk dry
  • Plant in full sun in deep soil that drains well, since both parent oaks handle clay and alkaline ground
  • Mulch the root zone with wood chips to slow evaporation in desert heat

Through the seasons

Water a new Heritage oak deeply and regularly through its first two or three summers as the roots spread out from the nursery ball. In the deserts, established trees still need deep soakings through the long hot season and during dry winter spells. Leaves emerge in spring, acorns with warty caps ripen in fall, and the leaves drop for winter. Back off in winter, but keep checking desert soil. WUCOLS rates Heritage oak moderate water in the high desert and in the low desert. WUCOLS has not evaluated it for the north-central coast, the Central Valley, the south coast or South Inland.

In pots

Heritage oak grows quickly into a large tree, so a nursery container is only a short stop. In desert heat, check the mix daily and water when the top 2 inches are dry, letting water run out of the drainage holes. Empty the saucer, and shade the pot itself from afternoon sun so the roots do not cook. Plant it out while it is young, before the roots circle the container. Water the leafless tree lightly in winter.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Heritage Oak for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Heritage Oak as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan––––0.740.78
Feb––––0.930.93
Mar––––1.461.52
Apr––––1.891.95
May––––2.392.45
Jun––––2.852.79
Jul––––3.042.85
Aug––––2.792.6
Sep––––2.142.08
Oct––––1.461.49
Nov––––0.930.96
Dec––––0.650.68
Year––––21.2721.08

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 not evaluated in the Central Valley, like Heritage oak. Plants that drink alike can share one valve and one schedule.

Hawthorn MapleAcer crataegifoliumnot rated, Central Valleyno Central Valley ratingMountain MapleAcer glabrumnot rated, Central Valleyno Central Valley ratingMiyabe MapleAcer miyabeinot rated, Central Valleyno Central Valley ratingEverglades PalmAcoelorraphe wrightiinot rated, Central Valleyno Central Valley ratingPink CedarAcrocarpus fraxinifoliusnot rated, Central Valleyno Central Valley ratingYellowwoodAfrocarpus falcatus (Podocarpus falcatus)not rated, Central Valleyno Central Valley ratingNew Caledonian PineAraucaria columnaris (A. cookii)not rated, Central Valleyno Central Valley ratingFormosa Sugar PalmArenga englerinot rated, Central Valleyno Central Valley ratingNeemAzadirachta indicanot rated, Central Valleyno Central Valley ratingBismarck PalmBismarckia nobilisnot rated, Central Valleyno Central Valley ratingAmerican HornbeamCarpinus caroliniananot rated, Central Valleyno Central Valley ratingJapanese HornbeamCarpinus japonicanot rated, Central Valleyno Central Valley ratingAmerican YellowwoodCladrastis kentukeanot rated, Central Valleyno Central Valley ratingPagoda DogwoodCornus alternifolianot rated, Central Valleyno Central Valley ratingGiant DogwoodCornus controversanot rated, Central Valleyno Central Valley ratingButterfly PalmDypsis lutescens (Areca)not rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes Heritage 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 Heritage oak need per day?

In July in the high desert, established Heritage oak needs about 7.7 gallons a day under a 10 foot canopy and about 31 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 Heritage oak change across California?

Yes. WUCOLS rates Heritage oak separately for each of the six California climate zones: not evaluated in the North-Central Coastal zone, not evaluated in the Central Valley zone, not evaluated in the South Coastal zone, not evaluated in the South Inland zone, moderate water in the High and Intermediate Desert zone, moderate water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

What is a Heritage oak?

It is the cultivar 'Clemons', a cross between English oak and bur oak chosen for vigor, a straight central leader and mildew-resistant leaves. Nurseries bud it onto swamp white oak rootstock, so remove any shoots that come from below the graft.

Does Heritage oak get powdery mildew?

It is highly resistant to powdery mildew, unlike its English oak parent in humid climates. Water at soil level anyway so the leaves stay dry.

How big does Heritage oak get?

The original tree measured about 40 feet tall and nearly as wide when it was described. Plan for a large shade tree with room for its roots and canopy.

Is Heritage oak strong in wind?

Yes. The original tree never lost a limb to wind or ice in more than 20 years of testing. That makes it a sound choice where strong wind is common.

Should I stake a Heritage oak?

Usually not. It grows a straight central leader on its own and does not need staking like many oaks. Stake only a nursery tree that cannot stand upright.

More plant watering guides

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Sources