WateringTimesWatering plan, $19
Salix babylonica, WUCOLS IV

How often to water weeping willow in California

In July in the Central Valley, established weeping willow in loam needs a deep watering about every 5 days: about 55 gallons each time under a 10 foot canopy, about 76 gallons a week. Weeping willow is a large, fast-growing deciduous tree with long, trailing branches that sweep toward the ground. It is naturally suited to streambanks and pond edges and wants soil that stays consistently moist, not merely occasional deep soakings. Its invasive roots can damage water or sewage pipes, so placement matters as much as irrigation.

TreeRated for 5 of 6 zones

How often to water weeping willow, 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 weeping willow 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 few inches down anywhere under the canopy signals a weeping willow needs water soon
  • Curling leaves or unusual drooping call for checking soil moisture beneath the hanging canopy
  • A thinning canopy warrants inspecting both growing conditions and the willow for pests or disease
  • Leaf spots or cankers need inspection even when soil around the willow is moist
  • Irrigation ponding against the trunk calls for checking for overwatering, even though willows tolerate wet ground

How to water it

  • Spread water beneath the weeping willow canopy rather than soaking only beside the trunk
  • Keep the soil consistently moist through the growing season instead of letting it dry out fully between waterings
  • Use drip lines or a soaker hose spread well beyond the canopy edge
  • Place a new willow well away from water pipes and sewage lines that its roots could damage
  • Expand the watered area each year as the canopy and root system continue to spread

Through the seasons

In its first year, a weeping willow needs frequent, generous watering while its wide root system establishes near a reliable moisture source. Established trees stay thirsty through the growing season and are a poor fit for gardens where water must be rationed. This deciduous tree leafs out in spring, grows quickly through summer and drops its leaves in fall, with the heaviest water use during that stretch. Winter rain can help meet its needs on the coast and in the valley, so check moisture before adding irrigation. WUCOLS rates weeping willow high water on the north-central coast, in the Central Valley and on the south coast. It also rates high water in South Inland and the high desert. WUCOLS has not evaluated it for the low desert.

In pots

For a young weeping willow in a container, use a roomy pot and check several inches into the mix during California heat. Keep the root ball moist, watering through the drainage holes and emptying the saucer afterward. Plan its eventual location carefully: this fast-growing tree can reach 30 to 40 feet tall and wide, and its roots can damage pipes. When the tree is leafless in winter, follow the moisture check rather than continuing summer irrigation automatically.

1 Your climate zone six WUCOLS zones, each from its own reference city
4.27gal per sq ft in JulyHigh water use in the Central Valley zone
A year
27.38 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
1.22.43.64.90.64JAN1.04FEB1.74MAR2.43APR3.32MAY3.97JUN4.27JUL3.82AUG2.88SEP1.88OCT0.89NOV0.55DEC1.22.43.64.90.64JFM2.43AMJ4.27JAS1.88OND
Gallons per square foot per month, Central Valley. Peak 4.27 in Jul, 27.38 a year.

Monthly water need by climate zone

Weeping Willow: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.60.641.241.241.19–
Feb0.841.041.291.391.49–
Mar1.391.741.842.082.33–
Apr1.882.432.232.583.03–
May2.333.322.583.123.82–
Jun2.583.972.783.674.56–
Jul2.584.273.174.024.86–
Aug2.383.822.983.724.46–
Sep1.982.882.382.983.42–
Oct1.391.881.842.132.33–
Nov0.740.891.341.441.49–
Dec0.50.551.041.091.04–
Year19.227.3824.829.4634.03–

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 high water in the Central Valley, like weeping willow. Plants that drink alike can share one valve and one schedule.

Big Leaf MapleAcer macrophyllumhigh water, Central Valley4.27 gal/sq ft in JulyWhite AlderAlnus rhombifoliahigh water, Central Valley4.27 gal/sq ft in JulyRed AlderAlnus rubra (Alnus oregona)high water, Central Valley4.27 gal/sq ft in JulyRiver BirchBetula nigrahigh water, Central Valley4.27 gal/sq ft in JulyWater BirchBetula occidentalishigh water, Central Valley4.27 gal/sq ft in JulyEuropean White BirchBetula pendulahigh water, Central Valley4.27 gal/sq ft in JulyWhite-Barked Himalayan BirchBetula utilis var. jacquemontiihigh water, Central Valley4.27 gal/sq ft in JulyEuropean BeechFagus sylvaticahigh water, Central Valley4.27 gal/sq ft in JulyBlack CottonwoodPopulus trichocarpa (Populus balsamifera)high water, Central Valley4.27 gal/sq ft in JulyCarolina PoplarPopulus x canadensishigh water, Central Valley4.27 gal/sq ft in JulyPeking WillowSalix matsudanahigh water, Central Valley4.27 gal/sq ft in JulyCoast RedwoodSequoia sempervirenshigh water, Central Valley4.27 gal/sq ft in JulyVine MapleAcer circinatumhigh water, Central Valley4.27 gal/sq ft in JulyHydrangeaHydrangea macrophylla & cvs.high water, Central Valley4.27 gal/sq ft in JulyBlueberriesVaccinium hybrids and cvs (CA native and non- native spp.)high water, Central Valley4.27 gal/sq ft in JulyShell GingerAlpinia zerumbethigh water, Central Valley4.27 gal/sq ft in July

Similar plants that need less water 16

Rated lower than weeping willow in the Central Valley. Worth a look for a new bed or a lawn replacement.

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
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes weeping willow, 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 weeping willow in summer?

In July, established weeping willow in loam needs a deep watering about every 5 days in the Central Valley, about every 7 days on the south coast and about every 5 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 weeping willow need per day?

In July in the Central Valley, established weeping willow needs about 11 gallons a day under a 10 foot canopy and about 43 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 weeping willow change across California?

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

Is weeping willow a good tree for a small California yard?

Its heavy water need and aggressive, searching roots make it a poor fit for a small lot or anywhere near pipes and foundations. It performs best near a pond, stream or low spot that stays naturally moist. Consider a smaller, less thirsty tree where space and water are limited.

Can weeping willow roots damage pipes?

Its invasive roots can damage water and sewage pipes. Choose a planting site well away from those services and allow room for the mature tree. Extra irrigation is not a dependable way to prevent root damage.

Why does my weeping willow have thin, sparse branches?

A sparse canopy needs investigation because willows can suffer several insect and disease problems. Check soil beneath the canopy as part of that inspection, since the tree prefers a moist root zone. Do not assume that changing irrigation alone will restore the branches.

Does weeping willow need less water once it is mature?

Not by much. Mature trees still want soil that stays evenly moist through the growing season rather than tolerating long dry spells like many established trees. Planting it where it can reach steady moisture matters more than reducing water with age.

Why is my weeping willow dropping leaves in summer?

Summer leaf loss is a reason to check the tree, rather than a diagnosis of drought. Inspect moisture around its roots and look for leaf damage or affected branches. Weeping willow normally retains leaves until fall, but several pests and diseases can affect its canopy.

More plant watering guides

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Sources