WateringTimesWatering plan, $19
Abies spp. (CA native and non-native), WUCOLS IV

How often to water fir trees in California

In July in the Central Valley, established fir trees in loam need a deep watering about every 8 days: about 55 gallons each time under a 10 foot canopy, about 47 gallons a week. Firs are evergreen conifers, and WUCOLS groups the California native firs with those from other regions. White fir, native to the Sierra Nevada and Rocky Mountains, has blue-green needles with a faint citrus scent. It handles heat and drought better than most firs. Firs want good drainage, and even white fir struggles where summers often top 100 degrees.

TreeCalifornia nativeRated for 3 of 6 zones

How often to water fir trees, 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 fir trees 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 6 inches down at the edge of the root ball means a young fir needs a deep soak
  • Needles browning at the tips during a heat wave can show drought and heat stress together
  • Yellowing needles and thinning on a tree in soggy ground point to root rot from poor drainage
  • Older inner needles shedding in fall is normal turnover, not a call for water
  • Slow growth of an inch or so a year can be normal for a fir and is not by itself a sign of thirst

How to water it

  • Water fir trees slowly around the root ball and outward with a soaker, keeping the trunk dry
  • Soak 18 inches deep, then let the top several inches dry before the next watering
  • Plant in moist, fertile soil with good drainage, avoiding heavy clay and wet spots
  • Shade a young fir by planting it at the edge of an oak or pine canopy where possible
  • Use needle mulch over the root zone and move irrigation outward as the tree grows

Through the seasons

Water a newly planted fir deeply through its first few summers while roots spread. Established trees still need deep soakings in long, hot summers, since most firs dislike heat and drought. The trees are evergreen and grow slowly. Irrigation matters most from late spring through early fall. Rain usually covers the cool months on the coast and in the Central Valley. Firs carry a moderate water rating in WUCOLS for the south coast, the Central Valley and the north-central coast. South Inland and both desert zones, the high desert and the low desert, are marked not suited.

In pots

Young firs, and dwarf forms such as 'Compacta' white fir, can live in large containers for a few years. Use a deep pot with drainage holes and a coarse, well-drained mix. Check 2 inches down every few days in warm weather and water when dry. Let water drain out, then empty the saucer. Keep the pot out of reflected afternoon heat, and in winter water only when the mix has dried.

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

Fir Trees: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.78–––
Feb0.530.650.81–––
Mar0.871.091.15–––
Apr1.181.521.4–––
May1.462.081.61–––
Jun1.612.481.74–––
Jul1.612.671.98–––
Aug1.492.391.86–––
Sep1.241.81.49–––
Oct0.871.181.15–––
Nov0.470.560.84–––
Dec0.310.340.65–––
Year1217.1115.5–––

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 fir trees. 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 fir trees 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 fir trees, 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 fir trees in summer?

In July, established fir trees in loam need 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 do fir trees need per day?

In July in the Central Valley, established fir trees need 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 fir trees change across California?

Yes. WUCOLS rates fir trees 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 suited to this region 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.

Can fir trees grow in hot inland gardens?

Most firs struggle with heat. Even white fir, one of the toughest, is not at its best where summers often top 100 degrees. WUCOLS marks firs as not suited to South Inland.

How fast do fir trees grow?

Slowly. White fir grows from about an inch to 2 feet a year, depending on climate and care. Expect the watered area to widen gradually.

Why plant a young fir near an oak or pine?

Outside its native range, a young white fir grows best with the shelter of a larger tree for its first years. Planting at the edge of an oak, fir or pine canopy gives that light shade.

Can you overwater fir trees?

Yes. Firs need good drainage, and heavy clay or wet spots can kill roots. Water deeply, then let the soil dry several inches down.

Why does my white fir smell like citrus?

Its needles carry a slight citrus fragrance. The scent is a trait of the species, not a sign of stress.

More plant watering guides

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Sources