WateringTimesWatering plan, $19
Bauhinia variegata (purpurea), WUCOLS IV

How often to water purple orchid tree in California

In July on the south coast, established purple orchid tree in loam needs a deep watering about every 11 days: about 55 gallons each time under a 10 foot canopy, about 35 gallons a week. Purple orchid tree is a fast-growing, semi-evergreen tree from India and China that reaches up to 35 feet, often on several trunks. Its large leaves are split into two rounded lobes, and its orchid-like flowers, about 5 inches wide, come in purple, pink or white. Seed pods up to a foot long follow the bloom. It needs full sun and deep, infrequent summer watering.

TreeRated for 3 of 6 zones

How often to water purple orchid 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 purple orchid 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

  • A trowel that turns up dry soil several inches down beneath the canopy in summer says the tree is ready for a deep soak
  • Brown, scorched leaf edges in midsummer call for a soil check, since leaf scorch shows up on some trees then
  • Yellowing leaves over soil that stays wet between waterings point to too much water
  • Sticky leaves and clouds of tiny white insects point to whiteflies rather than a watering problem
  • Spots on the leaves suggest leaf spot or anthracnose, which more water will not cure

How to water it

  • Lay drip or a slow soaker under the whole canopy so each session wets the soil deeply
  • Water deeply but infrequently in summer, letting the upper several inches dry between soakings
  • Plant in full sun in soil that drains well
  • Stake a young tree so its multiple trunks do not break in wind
  • Mulch the root zone and widen the watered area as the canopy spreads

Through the seasons

Water a young tree regularly through its first summers while roots spread, and keep it staked until the trunks firm up. Established trees do well with deep, infrequent soakings in summer. Trees sold under this name bloom at different times, some in fall and others from late winter into spring, and long pods follow the flowers. Winter rain usually covers it on the south coast, while low desert trees need checks in dry spells. WUCOLS rates purple orchid tree moderate water on the south coast, in South Inland and in the low desert. WUCOLS marks it as not suited to the north-central coast, the Central Valley or the high desert.

In pots

Purple orchid tree grows up to 35 feet, so a container suits only a young plant waiting to go in the ground. Use a deep pot with wide drainage holes and a well-drained mix, and set it in full sun. In summer heat, feel the mix 2 inches down every couple of days and water once it is dry there. Water until it runs from the base, then dump the saucer. In winter, water only after the mix dries, and keep the pot out of frost.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Purple Orchid Tree for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Purple Orchid Tree as not suited to this region for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan––0.780.78–0.78
Feb––0.810.87–0.93
Mar––1.151.3–1.52
Apr––1.41.61–1.95
May––1.611.95–2.45
Jun––1.742.29–2.79
Jul––1.982.51–2.85
Aug––1.862.33–2.6
Sep––1.491.86–2.08
Oct––1.151.33–1.49
Nov––0.840.9–0.96
Dec––0.650.68–0.68
Year––15.518.41–21.08

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 not suited to this region in the Central Valley, like purple orchid tree. Plants that drink alike can share one valve and one schedule.

Sugar MapleAcer saccharumnot rated, Central Valleyno Central Valley ratingQueensland KauriAgathis robustanot rated, Central Valleyno Central Valley ratingCherimoyaAnnona cherimolanot rated, Central Valleyno Central Valley ratingToogBischofia javanicanot rated, Central Valleyno Central Valley ratingClustered Fishtail PalmCaryota mitisnot rated, Central Valleyno Central Valley ratingWhite SapoteCasimiroa edulisnot rated, Central Valleyno Central Valley ratingFilbertCorylus maximanot rated, Central Valleyno Central Valley ratingSpotted GumCorymbia maculata (Eucalyptus maculata)not rated, Central Valleyno Central Valley ratingDove TreeDavidia involucratanot rated, Central Valleyno Central Valley ratingRoyal PoincianaDelonix regianot rated, Central Valleyno Central Valley ratingTriangle PalmDypsis decaryinot rated, Central Valleyno Central Valley ratingMountain White GumEucalyptus dalrympleananot rated, Central Valleyno Central Valley ratingRainbow EucalyptusEucalyptus degluptanot rated, Central Valleyno Central Valley ratingRoxburgh FigFicus auriculatanot rated, Central Valleyno Central Valley ratingIndian BanyanFicus benghalensisnot rated, Central Valleyno Central Valley ratingWeeping Chinese BanyanFicus benjaminanot rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes purple orchid 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 purple orchid tree in summer?

In July, established purple orchid tree in loam needs a deep watering 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 purple orchid tree need per day?

In July on the south coast, established purple orchid tree needs about 5.0 gallons a day under a 10 foot canopy and about 20 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 purple orchid tree change across California?

Yes. WUCOLS rates purple orchid tree separately for each of the six California climate zones: not suited to this region in the North-Central Coastal zone, not suited to this region in the Central Valley zone, moderate water in the South Coastal zone, moderate water in the South Inland zone, not suited to this region 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.

What are the long pods on my orchid tree?

They are seed pods, up to about a foot long, that form after the flowers fade. They hang from the branches for a while. Thinning crowded growth after bloom removes many of them.

When does purple orchid tree bloom?

It depends on the tree. Some bloom in fall, roughly September to November, while others flower from late winter into spring. The flowers are large, slightly fragrant and shaped like orchids.

Is purple orchid tree evergreen?

It is semi-evergreen, so it can lose part of its foliage while keeping some leaves. Some leaf drop is normal for a semi-evergreen tree and not by itself a sign of drought.

Why did my orchid tree trunk split?

Young trees often grow several trunks that break easily in wind. Stake a young tree until it grows taller and sturdier, and remove crowded stems after flowering.

Can you overwater purple orchid tree?

Yes. Orchid trees suffer from too much water as well as too little, and constantly wet soil harms the roots. Water deeply, then let the soil dry well before the next round.

More plant watering guides

Hawaiian TiFilbertSpotted GumDove TreeRoyal PoincianaTriangle PalmMountain White GumRainbow Eucalyptus

Sources