WateringTimesWatering plan, $19
Liquidambar styraciflua, WUCOLS IV

How often to water sweet gum in California

In July in the Central Valley, established sweet gum 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. Sweet gum is a large, fast-growing deciduous tree from the eastern United States and Mexico. Its glossy, star-shaped leaves turn red, purple, orange and yellow in fall and hang on for a long time. Spiny gumballs litter the ground through winter and spring, and its shallow roots make deep soakings more useful than frequent light watering.

TreeRated for 6 of 6 zones

How often to water sweet gum, 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 sweet gum 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 4 to 6 inches down beneath the canopy in summer signals that sweet gum needs a deep soak
  • Leaves scorching brown at the edges in midsummer can follow a dry root zone during heat
  • Yellow leaves with green veins point to iron chlorosis from alkaline soil, which extra water does not fix
  • Wilting over soggy soil, or a soft, rotting root crown, points to root rot in poorly drained ground
  • Tiny round holes in the trunk with wet staining or gummy ooze warrant a look for shot hole borers

How to water it

  • Water slowly under the canopy with drip or a soaker hose, keeping the trunk itself dry
  • Soak the soil 18 inches to 2 feet deep and let the upper few inches dry between soakings
  • Plant in moist, well-drained, neutral to acidic soil, away from walks and foundations its roots can lift
  • Mulch the root zone with wood chips instead of lawn, so turf sprinklers do not set the tree's watering
  • Move emitters outward as the canopy spreads toward its mature 40 foot width

Through the seasons

A newly planted sweet gum needs deep soakings through its first two or three summers. Spring planting gives its roots time to recover before heat. Established trees still want deep summer soakings, spaced so the topsoil dries between them. Fall color lingers before the leaves finally drop, and the tree rests through winter. Rain covers its dormant months on the coast and in the Central Valley; desert trees need winter soil checks. WUCOLS rates sweet gum moderate water on the north-central coast, in the Central Valley, on the south coast and in South Inland. It holds that moderate water rating in the high desert and the low desert as well.

In pots

Sweet gum grows into a large tree, so a pot suits only a young sapling or a dwarf form. Use a deep container and check the mix 2 to 3 inches down every few days in summer. Water until it runs from the drainage holes, then empty the saucer. Plant it out in spring, since its roots recover slowly from transplanting. After leaf fall, the dormant tree needs only light watering until the buds swell.

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
0.761.52.33.00.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.761.52.33.00.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Sweet Gum: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.780.740.78
Feb0.530.650.810.870.930.93
Mar0.871.091.151.31.461.52
Apr1.181.521.41.611.891.95
May1.462.081.611.952.392.45
Jun1.612.481.742.292.852.79
Jul1.612.671.982.513.042.85
Aug1.492.391.862.332.792.6
Sep1.241.81.491.862.142.08
Oct0.871.181.151.331.461.49
Nov0.470.560.840.90.930.96
Dec0.310.340.650.680.650.68
Year1217.1115.518.4121.2721.08

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 moderate water in the Central Valley, like sweet gum. 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 sweet gum 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 sweet gum, 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 sweet gum in summer?

In July, established sweet gum 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 sweet gum need per day?

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

Yes. WUCOLS rates sweet gum 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, moderate 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.

Is there a sweet gum without gumballs?

Yes, a few fruitless cultivars produce no gumballs while keeping the fall color. Ask a nursery for a fruitless selection. Water it the same way as the species.

Why are sweet gum roots lifting my sidewalk?

Its roots are shallow and vigorous, with a high potential to damage paving. Deep, spaced soakings suit it better than frequent light watering near hardscape. Plant new trees well away from walks and foundations.

Why are my sweet gum leaves yellow in summer?

Yellow leaves with green veins usually mean iron chlorosis from alkaline soil. Extra water will not cure it. Correct the soil pH or iron supply instead.

When do sweet gum gumballs fall?

The spiny fruits drop from about December into spring and can litter lawns and patios. Rake them up before mowing. Their timing has nothing to do with water stress.

Is sweet gum drought tolerant?

It handles short dry spells, but WUCOLS rates it moderate water everywhere it is grown in California. Plan on deep soakings through the dry season, especially for young trees.

More plant watering guides

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Sources