WateringTimesWatering plan, $19
Gleditsia triacanthos, WUCOLS IV

How often to water honey locust in California

In July in the Central Valley, established honey locust in loam needs a deep watering about every 20 days: about 55 gallons each time under a 10 foot canopy, about 19 gallons a week. Honey locust is a fast-growing deciduous shade tree whose small leaflets cast light, dappled shade and turn yellow in fall. Thornless forms are the ones to plant, and some are podless as well. Once established it handles drought, wind and salt in most zones, and it adapts to nearly any soil, even ground that floods now and then.

TreeRated for 6 of 6 zones

How often to water honey locust, 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 honey locust 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 under the canopy edge of a young honey locust means it needs a deep soak
  • Leaflets yellowing and dropping in midsummer, long before fall color, can follow a long dry spell on a young tree
  • Thin, yellowing foliage over soil that never dries between lawn waterings can mean the roots are short of air
  • Webbed clusters of browned leaflets in summer point to webworms rather than dry soil
  • Pale blotches and mines in the leaflets come from locust leafminers, which watering does not cure

How to water it

  • Water a young honey locust over the root ball and well beyond it, widening the wet area each year
  • Run water slowly until it has sunk about 18 inches, and wait for the upper several inches to dry before the next soak
  • Once it is established, give occasional deep soakings under the outer canopy instead of frequent light ones
  • Plant in full sun in almost any soil, from clay to loam, where the roots can spread freely
  • Keep thick mulch and turf a few feet back from the trunk so the bark at the base stays dry

Through the seasons

Water a new honey locust deeply through its first summer or two, then taper off as the roots spread. Small greenish flowers open in late spring, and fruiting types set long, twisted pods by summer. Leaflets turn yellow and drop in fall, while pods can hang on through winter. Along the coast and through the valley, winter storms usually water the dormant tree. WUCOLS rates honey locust moderate water on the south coast. Everywhere else it rates low water: the low desert, the high desert, South Inland, the Central Valley and the north-central coast.

In pots

Honey locust grows fast into a large tree, so a container suits only a young tree waiting to be planted. During summer, dig a finger into the mix every few days, and check daily once desert heat arrives. Water until the excess drains out, then tip out the saucer. A crowded root ball dries quickly, which is a sign the tree should go into the ground. The leafless winter tree needs very little, so wait until the mix has dried a couple of inches down.

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
0.490.991.52.00.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.490.991.52.00.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

Honey Locust: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.160.780.310.30.31
Feb0.210.260.810.350.370.37
Mar0.350.431.150.520.580.61
Apr0.470.611.40.640.760.78
May0.580.831.610.780.950.98
Jun0.640.991.740.921.141.12
Jul0.641.071.9811.221.14
Aug0.60.951.860.931.121.04
Sep0.50.721.490.740.860.83
Oct0.350.471.150.530.580.6
Nov0.190.220.840.360.370.38
Dec0.120.140.650.270.260.27
Year4.86.8415.57.378.518.43

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 honey locust. 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 honey locust, 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 honey locust in summer?

In July, established honey locust in loam needs a deep watering about every 20 days in the Central Valley, about every 11 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 does honey locust need per day?

In July in the Central Valley, established honey locust needs 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 honey locust change across California?

Yes. WUCOLS rates honey locust separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, moderate water in the South Coastal zone, low water in the South Inland zone, low water in the High and Intermediate Desert zone, low water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Can grass grow under a honey locust?

Yes. Its small leaflets cast light shade that lets a lawn grow underneath. Lawn watering gives an established tree more than it needs, so keep sprinkler spray off the trunk.

Are honey locust thorns dangerous?

Wild trees carry stout, branched thorns up to 3 inches long on the trunk and limbs. Plant the thornless variety inermis or one of its named cultivars instead.

Are honey locust pods edible?

The sweet, sticky pulp inside the pods is edible and gives the tree its name. Fallen pods are messy, so a podless cultivar such as 'Sunburst' saves clean-up.

Why does my honey locust send up sprouts?

Cutting or mowing around the tree can trigger new sprouts, and seedlings come up from fallen pods. Pull seedlings early. A podless cultivar avoids most of them.

Is honey locust a good tree near the coast?

Yes. Established trees tolerate salt and wind well. On the south coast WUCOLS rates it moderate water, so summer soil checks matter more there than in its low water zones.

More plant watering guides

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Sources