WateringTimesWatering plan, $19
Phoenix dactylifera, WUCOLS IV

How often to water date palms in California

In July in the Central Valley, established date palms in loam need a deep watering about every 20 days: about 55 gallons each time under a 10 foot canopy, about 19 gallons a week. Date palms are tall feather palms from desert oases, built for heat, sun and dry air. Once established they rate as low water plants in most of California and moderate water in the deserts. Their roots need well drained soil and plenty of oxygen, so deep, occasional soakings suit them far better than frequent light sprinkles.

TreePalm or cycadRated for 6 of 6 zones

How often to water date palms, 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 date palms 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 that has dried about 2 inches down within the root zone is the cue to water an established date palm
  • Moist soil at that depth means wait, because constantly wet ground starves palm roots of the oxygen they need
  • Pale, stunted new leaves in soil that stays wet point to too much water or poor drainage rather than thirst
  • Yellow or orange flecks on the oldest fronds usually mean a potassium or magnesium shortage, not a need for more water

How to water it

  • Water slowly and evenly over the whole root zone until the soil is moist about a foot deep
  • Split a long watering into several shorter runs when water starts to run off hard or sloping ground
  • Plant in well drained soil and never let water pond around the base of the trunk
  • Keep groundcovers and shrubs a couple of feet back from the trunk and spread organic mulch around the base

Through the seasons

A newly planted date palm needs steady moisture through its first summers while its roots spread. Soggy ground harms it most at this stage. Established palms are evergreen and draw water all year, most of all through the long hot season from late spring to early fall. WUCOLS rates date palms as low water on the north-central coast, in the Central Valley, on the south coast and in South Inland. It rates them as moderate water in the high and low deserts. Along the coast and in the Central Valley, winter rain usually covers the cool months. In the deserts, keep checking the soil through winter and water when it dries.

In pots

Date palms grow far too large for containers in the long run, so a pot suits only a young plant. Use a wide, heavy pot with a fast draining mix. In summer heat, check the mix a couple of inches down every few days and water when it has dried, until water runs from the drainage holes. Empty the saucer each time, because standing water rots palm roots. Water far less in winter, when growth slows.

1 Your climate zone six WUCOLS zones, each from its own reference city
1.07gal per sq ft in JulyLow water use in the Central Valley zone
A year
6.84 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.761.52.33.00.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.761.52.33.00.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

Date Palms: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.160.310.310.740.78
Feb0.210.260.320.350.930.93
Mar0.350.430.460.521.461.52
Apr0.470.610.560.641.891.95
May0.580.830.640.782.392.45
Jun0.640.990.690.922.852.79
Jul0.641.070.7913.042.85
Aug0.60.950.740.932.792.6
Sep0.50.720.60.742.142.08
Oct0.350.470.460.531.461.49
Nov0.190.220.330.360.930.96
Dec0.120.140.260.270.650.68
Year4.86.846.27.3721.2721.08

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 low water in the Central Valley, like date palms. Plants that drink alike can share one valve and one schedule.

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 date palms, 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 date palms in summer?

In July, established date palms in loam need a deep watering about every 20 days in the Central Valley, about every 27 days on the south coast and about every 22 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 do date palms need per day?

In July in the Central Valley, established date palms need about 2.7 gallons a day under a 10 foot canopy and about 11 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 date palms change across California?

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

Do date palms need a lot of water?

Not once they are established. Across most of the state they are low water palms, and the two desert zones call for moderate water. Water deeply when the soil dries a couple of inches down, then let it dry again.

Can I overwater a date palm?

Yes. Palm roots need oxygen, and soil that stays wet for long periods starves and rots them. Pale, stunted new leaves in wet soil are a common warning. Improve drainage and wait for the top of the soil to dry before watering again.

How deep should I water a date palm?

Wet the soil about a foot deep across the whole root zone each time. On slopes or heavy clay, split the watering into shorter runs so it soaks in instead of running off.

Why are the old fronds on my date palm turning yellow?

Yellow or orange flecking on the oldest fronds usually points to a potassium or magnesium shortage, which palms are prone to. Extra water will not fix it. A palm fertilizer high in nitrogen, potassium and magnesium, used as the label directs, is the usual remedy.

Do date palms need heat to fruit?

Yes. WUCOLS notes that date palms need summer heat to bear fruit, and only female trees produce it. Extra water does not replace heat, so it will not bring a crop in a cool garden.

Should I trim the fronds of a date palm?

Only lightly. Heavy pruning leaves wounds that let disease into the palm. Remove dead fronds, and avoid cutting leaves above the horizontal line through the crown.

More plant watering guides

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Sources