How often to water Emory oak in California
In July on the north-central coast, established Emory oak in loam needs a deep soak only about once a month or less: about 55 gallons each time under a 10 foot canopy. Emory oak is a slow-growing oak from the mountains and foothills along the Mexican border, from Arizona to western Texas. Its glossy, leathery leaves have wavy or spiny edges, a little like holly. It keeps them through winter and sheds the old ones in spring. A deep taproot lets an established tree ride out dry spells, but a young one needs help.
How often to water Emory oak, month by month
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.
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.
How to tell it needs water
- Dry soil 4 to 6 inches down at the edge of a young Emory oak's root ball means it is time for a deep soak
- Wilting new shoots on a young tree, with dry soil below, point to a thirsty root zone
- A heavy drop of leaves in summer can mean the tree has been kept too dry, since it sheds some foliage when grown dry
- Old leaves coloring and falling in spring as new growth emerges is normal and not a sign of thirst
- Yellowing leaves or dieback while the soil near the trunk stays wet point to poor drainage, since this oak needs well-drained soil
How to water it
- Water a young Emory oak slowly over its root ball and the soil just beyond, widening the area as the roots spread
- Soak deeply enough to follow the taproot down, then let the upper soil dry before the next soak
- Keep water from pooling against the trunk, and place drip emitters toward the outer canopy of an older tree
- Plant it in full sun in loam or sand that drains well, away from low spots that stay wet
- Set a young tree in its final spot early, since it forms a deep taproot that makes later moves hard
Through the seasons
Give a young Emory oak deep soakings through its first summers while the taproot works down. Growth is slow, so the tree stays young for a while. Once established it handles dry spells, though it sheds some leaves in summer if kept very dry. It holds its leaves through winter, then drops the old ones in spring as new leaves and flowers appear. Winter rain covers the cool months on the north-central coast, where WUCOLS rates it low water. WUCOLS has not evaluated it for the Central Valley, the south coast or South Inland. WUCOLS marks it as not suited to the high desert or the low desert.
In pots
Emory oak forms a deep taproot, so it belongs in a container only briefly. Grow a seedling in a tall pot and plant it out within its first two seasons. Check the mix 2 to 3 inches down every few days in summer heat. Water until it drains from the holes, then empty the saucer so the taproot does not sit in water. A young oak in a pot cannot reach deeper moisture, so it dries faster than one in the ground. In winter, let rain do most of the work and check the mix during dry spells.
- A year
- no figure
- Reference
- Sacramento climate table
- Counts
- Plant need, before sprinkler losses
WUCOLS lists Emory Oak as not evaluated for the Central Valley zone, so no monthly figure is computed here.
Monthly water need by climate zone
Emory Oak: gallons per square foot per month, by WUCOLS climate zone
| Month | N. Coast | C. Valley | S. Coast | S. Inland | Hi Desert | Lo Desert |
|---|---|---|---|---|---|---|
| Jan | 0.15 | – | – | – | – | – |
| Feb | 0.21 | – | – | – | – | – |
| Mar | 0.35 | – | – | – | – | – |
| Apr | 0.47 | – | – | – | – | – |
| May | 0.58 | – | – | – | – | – |
| Jun | 0.64 | – | – | – | – | – |
| Jul | 0.64 | – | – | – | – | – |
| Aug | 0.6 | – | – | – | – | – |
| Sep | 0.5 | – | – | – | – | – |
| Oct | 0.35 | – | – | – | – | – |
| Nov | 0.19 | – | – | – | – | – |
| Dec | 0.12 | – | – | – | – | – |
| Year | 4.8 | – | – | – | – | – |
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 Emory oak. Plants that drink alike can share one valve and one schedule.
Hawthorn MapleAcer crataegifoliumnot rated, Central Valleyno Central Valley rating
Mountain MapleAcer glabrumnot rated, Central Valleyno Central Valley rating
Miyabe MapleAcer miyabeinot rated, Central Valleyno Central Valley rating
Everglades PalmAcoelorraphe wrightiinot rated, Central Valleyno Central Valley rating
Pink CedarAcrocarpus fraxinifoliusnot rated, Central Valleyno Central Valley rating
YellowwoodAfrocarpus falcatus (Podocarpus falcatus)not rated, Central Valleyno Central Valley rating
New Caledonian PineAraucaria columnaris (A. cookii)not rated, Central Valleyno Central Valley rating
Formosa Sugar PalmArenga englerinot rated, Central Valleyno Central Valley rating
NeemAzadirachta indicanot rated, Central Valleyno Central Valley rating
Bismarck PalmBismarckia nobilisnot rated, Central Valleyno Central Valley rating
American HornbeamCarpinus caroliniananot rated, Central Valleyno Central Valley rating
Japanese HornbeamCarpinus japonicanot rated, Central Valleyno Central Valley rating
American YellowwoodCladrastis kentukeanot rated, Central Valleyno Central Valley rating
Pagoda DogwoodCornus alternifolianot rated, Central Valleyno Central Valley rating
Giant DogwoodCornus controversanot rated, Central Valleyno Central Valley rating
Butterfly PalmDypsis lutescens (Areca)not rated, Central Valleyno Central Valley ratingTurn this into minutes on your water days
Every city page has a calculator that takes Emory 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 Emory oak need per day?
In July on the north-central coast, established Emory oak needs about 1.6 gallons a day under a 10 foot canopy and about 6.5 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 Emory oak change across California?
Yes. WUCOLS rates Emory oak separately for each of the six California climate zones: low water 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, not suited to this region in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.
Is Emory oak evergreen?
Nearly. Its leaves stay on the tree through the cold months. In spring the old leaves can turn orange and fall as fresh leaves and flowers open.
Are Emory oak acorns edible?
Yes. Native Americans ground them into flour and meal, and they are still sold as food in parts of northwestern Mexico. Many wild animals eat them as well.
Why is my Emory oak dropping leaves in summer?
It sheds some leaves in summer when it is grown dry. Check the soil several inches down at the edge of the root zone. If it is dry, give a slow, deep soak.
How fast does Emory oak grow?
Slowly, more slowly than many oaks. Over time it builds a rounded, wide spreading crown. Give it a spot with room for a large shade tree.
Can I transplant an Emory oak?
Moving it is hard because it forms a deep taproot early. Plant it in its final spot while young, within its first two seasons. Water a new planting deeply so the root ball does not dry out.
Is Emory oak good for wildlife?
Yes. In its home range it feeds deer for much of the year, and butterflies and moths visit its flowers. Many animals use it for shelter.
More plant watering guides
Sources
- WUCOLS IV plant water use classification for Quercus emoryi, the University of California survey California agencies use for landscape plan reviewRead August 23, 2026 on wucols.ucdavis.edu
- Model Water Efficient Landscape Ordinance, adopted text and appendices, effective 2025-01-02 · monthly reference evapotranspiration per city, Appendix CRead August 23, 2026 on water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/Water-Use-And-Efficiency/MWELO-Rulemaking/Final-MWELO-Text-and-Appendices_20250103.pdf
- UC Statewide IPM Program, irrigation scheduling using evapotranspirationRead September 30, 2026 on ipm.ucanr.edu/PMG/GARDEN/ENVIRON/evap.html
- Shaw and Pittenger, Landscape Irrigation System Evaluation and Management, UC Cooperative Extension, 2009Read September 30, 2026 on ucanr.edu/sites/default/files/2013-02/160836.pdf
- Pittenger, Water Management in Gardens and Landscapes, UC Riverside, 2017Read September 30, 2026 on ucanr.edu/sites/default/files/2017-03/258022.pdf