WateringTimesWatering plan, $19
Acer rubrum, WUCOLS IV

How often to water red maple in California

In July in the Central Valley, established red maple 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. Red maple is a fast growing deciduous shade tree from eastern North America, usually 40 to 70 feet tall with a rounded crown. Clusters of small red flowers open in late winter, and the leaves turn red early in fall. It prefers moist, slightly acidic soil and steady water, and it can turn chlorotic in alkaline soil.

TreeRated for 4 of 6 zones

How often to water red maple, 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 red maple 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 3 to 4 inches down beneath the canopy signals that red maple needs a deep soak
  • Leaf edges browning and curling in summer heat can indicate a dry root zone
  • Yellow leaves with green veins point to chlorosis from alkaline soil rather than thirst
  • Wilting on one side of the tree, with branches dying back, can signal Verticillium wilt
  • Yellowing leaves over soil that stays waterlogged for long periods can indicate root rot

How to water it

  • Water the whole area beneath the canopy, where the dense mat of shallow roots spreads
  • Soak slowly to about a foot deep, then water again once the top few inches dry
  • Spread organic mulch over the root zone rather than planting a lawn or bed beneath it
  • Plant in moist, slightly acidic soil, and pick another tree where the ground is strongly alkaline
  • Keep it well back from sidewalks and driveways, which its shallow roots can buckle

Through the seasons

Keep a new red maple evenly moist through its first two summers while roots spread. Established trees still want regular deep soakings through the dry season, since the species prefers moist soil. Flowers open in late winter, and fall color arrives early. WUCOLS rates red maple moderate water on the north-central coast and in the Central Valley. It rates high water on the south coast and in South Inland. WUCOLS marks it as not suited to the high desert or the low desert. Winter rain usually supplies the leafless tree on the coast and in the Central Valley.

In pots

Red maple grows fast into a large tree, so a container suits only a young plant before it goes into the ground. Use a deep pot with drainage holes and a moisture-holding, slightly acidic mix. In summer heat, feel the mix 2 inches down every few days and water before it dries out. Water until excess drains, then empty the saucer. Give the pot some afternoon shade in hot inland gardens. After leaf fall, keep the mix barely moist through winter.

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
1.02.03.04.00.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC1.02.03.04.00.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Red Maple: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.41.241.24––
Feb0.530.651.291.39––
Mar0.871.091.842.08––
Apr1.181.522.232.58––
May1.462.082.583.12––
Jun1.612.482.783.67––
Jul1.612.673.174.02––
Aug1.492.392.983.72––
Sep1.241.82.382.98––
Oct0.871.181.842.13––
Nov0.470.561.341.44––
Dec0.310.341.041.09––
Year1217.1124.829.46––

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 red maple. 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 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 JulyItalian AlderAlnus cordatamoderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

Rated lower than red maple 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 red maple, 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 red maple in summer?

In July, established red maple in loam needs a deep watering about every 8 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 red maple need per day?

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

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

Why are my red maple leaves yellow with green veins?

This is chlorosis, a nutrient problem that shows up when red maple grows in alkaline soil. Extra water will not cure it. Soil treatments can help, but a tree suited to alkaline ground is the lasting fix.

Why won't anything grow under my red maple?

Red maple forms a dense mat of shallow roots that outcompete plants in its shade. Mulch the area instead of planting a lawn or flower bed there. Water the mulched root zone along with the tree.

Do red maple roots damage paving?

Its shallow roots can buckle nearby sidewalks and driveways. Plant it well away from paving and foundations.

When does red maple show fall color?

Its leaves turn red early in fall, though the color varies from tree to tree and among cultivars. Clusters of small red flowers follow in late winter.

Can you overwater a red maple?

It tolerates occasional flooding and wet soil. Still, ground that stays waterlogged can lead to root rot. Let the surface dry slightly between soakings.

More plant watering guides

Curly Top SedgeEuropean HornbeamBean TreeMadagascar PeriwinkleButtonbushKatsura TreeEastern RedbudChinese Redbud

Sources