WateringTimesWatering plan, $19
Cercis siliquastrum, WUCOLS IV

How often to water Judas tree in California

In July in the Central Valley, established Judas tree 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. Judas tree, also called Mediterranean redbud or love tree, is a deciduous small tree, often 15 to 25 feet tall and nearly as wide. Clusters of magenta pink, pea-shaped flowers cover its bare branches and older stems in early spring. Heart-shaped leaves and flat purplish pods follow. It wants well-drained soil and deep, unhurried soakings.

ShrubTreeRated for 3 of 6 zones

How often to water Judas tree, 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 Judas tree 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 edge signals that an established Judas tree needs a deep soak
  • Leaves dulling or dropping early in a hot, dry summer can indicate a dry root zone
  • Yellowing leaves over soil that stays wet can indicate poor drainage, which this tree handles badly
  • One branch wilting suddenly while the rest stays green points to Verticillium wilt rather than thirst
  • Small coral pink bumps on dead twigs are coral spot, a fungus that follows dieback, not a water shortage

How to water it

  • Water a young Judas tree over its root ball and the soil just beyond, widening the area as roots spread
  • For an established tree, apply water beneath the outer canopy and beyond rather than at the trunk
  • Run water slowly so it reaches 12 to 18 inches down, then let the upper soil dry before the next soak
  • Plant in well-drained soil, using a gentle mound where clay holds water
  • Spread wood-chip mulch across the root area, keeping it clear of the trunk

Through the seasons

Water a new Judas tree deeply through its first two summers while roots spread into native soil. WUCOLS rates Judas tree moderate water on the north-central coast, in the Central Valley and on the south coast. WUCOLS has not evaluated it for South Inland, the high desert or the low desert. Established trees take deeper, more widely spaced soakings during the dry season. Flowers open on bare wood in early spring and leaves follow, so water use climbs from spring into summer. After leaf fall the tree rests, and winter rain usually supplies it on the coast and in the Central Valley.

In pots

Judas tree grows into a 15 to 25 foot tree, so a container suits only a young plant for a few years. Use a large, deep pot with open drainage holes and a mix that drains freely. In summer heat, feel the mix 2 inches down every few days and water when it is dry there. Soak until excess drains, then empty the saucer. After leaf drop, water much less, keeping the mix barely moist through winter. Plant it in the ground before the roots circle the pot.

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
0.671.32.02.70.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.671.32.02.70.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Judas Tree: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.78–––
Feb0.530.650.81–––
Mar0.871.091.15–––
Apr1.181.521.4–––
May1.462.081.61–––
Jun1.612.481.74–––
Jul1.612.671.98–––
Aug1.492.391.86–––
Sep1.241.81.49–––
Oct0.871.181.15–––
Nov0.470.560.84–––
Dec0.310.340.65–––
Year1217.1115.5–––

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 Judas tree. Plants that drink alike can share one valve and one schedule.

RosesRosa hybrids..bushmoderate water, Central Valley2.67 gal/sq ft in JulyCitrus TreesCitrus spp.moderate water, Central Valley2.67 gal/sq ft in JulyAzaleasRhododendron spp. (CA native and non-native spp.)moderate water, Central Valley2.67 gal/sq ft in JulyCamelliasCamellia japonica (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in JulyGardeniasGardenia spp. & cvs.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 JulyBird of ParadiseStrelitzia reginae (shade in desert)moderate water, Central Valley2.67 gal/sq ft in JulyHibiscusHibiscus rosa-sinensismoderate 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 JulySago PalmCycas revolutamoderate water, Central Valley2.67 gal/sq ft in JulyStar JasmineTrachelospermum jasminoides and cvs.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 July

Similar plants that need less water 16

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

LavenderLavandula spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRosemaryRosmarinus officinalislow water, Central Valley1.07 gal/sq ft in JulyBougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyOlive 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 JulyLantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in JulyAloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySucculentsEcheveria 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 JulyRussian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySagebrushArtemisia spp. (shrubby)low 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 Judas tree, 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 Judas tree in summer?

In July, established Judas tree in loam needs a deep watering about every 8 days in the Central Valley and about every 11 days on the south coast. 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 Judas tree need per day?

In July in the Central Valley, established Judas tree 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 Judas tree change across California?

Yes. WUCOLS rates Judas tree 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, not evaluated in the South Inland zone, not evaluated 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.

Why is it called a Judas tree?

The name comes from a legend that Judas Iscariot hanged himself on this kind of tree. Its closest garden relatives are the redbuds, including the western redbud native to California. It is also sold as Mediterranean redbud.

Why are flowers growing on the trunk of my Judas tree?

Flower clusters form on older stems and branches as well as on recent growth. This is normal for the tree. Avoid cutting away older wood if you want the full spring show.

Can Judas tree handle dry summers?

Established trees cope with some dryness, but WUCOLS rates it moderate water wherever it has been rated. Give it deep soakings through the dry season rather than leaving it to rain alone. Young trees need more help than mature ones.

Can you overwater a Judas tree?

Yes. It needs well-drained soil, and roots kept wet in heavy clay can decline. Let the upper soil dry between soakings and keep lawn sprinklers away from the trunk area.

What are the purple pods on my Judas tree?

They are flat seed pods, up to about 5 inches long, that follow the flowers. They are normal and need no special care.

How cold hardy is Judas tree?

Established trees handle winter lows of about 10 to 15 degrees F. It is leafless through winter, which is also its resting season. Water sparingly while it is bare.

More plant watering guides

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Sources