WateringTimesWatering plan, $19
Pistacia vera (edible), WUCOLS IV

How often to water pistachio in California

In July in the Central Valley, established pistachio 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. Pistachio is a deciduous tree native to the dry hills of central and southwestern Asia, grown in California for its split, cream-colored nuts. It carries a deep, wide-ranging root system that draws moisture from well below the surface once established. Good drainage matters more to this tree than frequent watering, since wet, humid soil suits it poorly.

TreeRated for 4 of 6 zones

How often to water pistachio, 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 pistachio 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 a foot or more down at the edge of a young pistachio's root ball signals that it needs water
  • Curled leaflets that stay limp into the evening can indicate a thirsty young tree
  • Irregular or delayed leaf-out in spring often follows a winter with too little chill, so check winter conditions before blaming soil moisture
  • Yellowing leaves with soil that stays constantly damp can indicate overwatering in this deep-rooted tree
  • Leaves yellowing and falling in autumn as the tree goes dormant is normal and does not by itself indicate thirst

How to water it

  • Soak the ground beneath a young pistachio and just past its canopy edge, expanding that circle as it grows
  • Direct drip or a slow trickle away from the trunk rather than pooling water against the crown
  • Pick a well-drained site or a raised planting area, since this tree handles dry soil far better than wet
  • Give the surface a real chance to dry out before soaking a mature tree again
  • Judge a mature tree's next soak by soil depth, not by how many days have passed

Through the seasons

A newly planted pistachio needs consistent moisture while its deep root system extends into the surrounding soil. Established trees lose their leaves each fall and need winter chill along with summer heat to fruit well. This species tolerates dry soil far better than constantly wet or humid ground. WUCOLS rates pistachio low water on the north-central coast. It rates moderate water in the Central Valley, on the south coast and in South Inland. WUCOLS marks it as not suited to the high desert. WUCOLS marks it as not suited to the low desert. Winter rain can cover dormant coastal and valley trees, but check the root zone during dry winter stretches.

In pots

A young pistachio can grow in a large container for a season or two before it goes into open ground, since its roots eventually need far more room than a pot allows. Feel the mix several inches down during California heat and water only once that depth turns dry. Let excess water run out through the drainage holes, then tip out the saucer rather than let the pot stand in it. Excess moisture in a container is riskier for this tree than letting the mix dry a bit longer. In winter, check less often since the leafless tree needs little moisture until spring growth begins.

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

Pistachio: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.40.780.78––
Feb0.210.650.810.87––
Mar0.351.091.151.3––
Apr0.471.521.41.61––
May0.582.081.611.95––
Jun0.642.481.742.29––
Jul0.642.671.982.51––
Aug0.62.391.862.33––
Sep0.51.81.491.86––
Oct0.351.181.151.33––
Nov0.190.560.840.9––
Dec0.120.340.650.68––
Year4.817.1115.518.41––

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 pistachio. 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 pistachio 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 pistachio, 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 pistachio in summer?

In July, established pistachio in loam needs a deep watering about every 8 days in the Central Valley, about every 11 days on the south coast and about every 9 days in the South Inland zone. 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 pistachio need per day?

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

Yes. WUCOLS rates pistachio separately for each of the six California climate zones: low water in the North-Central Coastal zone, moderate water in the Central Valley zone, moderate water in the South Coastal zone, moderate water 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.

Do I need more than one pistachio tree to get nuts?

Yes, pistachio trees are either male or female, and both are needed for fruit to form. A single tree of either sex will not produce a nut crop on its own. This is separate from how much water either tree receives.

Why is my pistachio tree not fruiting well?

Check whether the tree received enough winter chill and summer heat, since both affect nut development. Confirm a male tree stands nearby for pollination before adjusting watering. Soil moisture is only one factor among several that shape the crop.

Can pistachio handle heavy or slow-draining soil?

This species does poorly in soil that stays wet or humid for long periods. Building up the planting area helps where the native ground drains slowly. Confirming depth before each watering matters more here than for a tree suited to wetter ground.

How do I water a young pistachio after planting?

Wet the whole root ball plus the ground just past its rim. Give the top layer real time to dry before the next round. Push the watered circle outward as the young roots reach further each season.

Does a mature pistachio need much irrigation?

Its deep, wide-ranging roots let an established tree draw on soil moisture well below the surface. It tolerates longer gaps between waterings than many other fruiting trees. Soil left constantly wet threatens a mature tree more than a stretch of moderate dryness.

More plant watering guides

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Sources