WateringTimesWatering plan, $19
Metrosideros excelsa (Metrosideros tomentosa), WUCOLS IV

How often to water New Zealand Christmas tree in California

In July on the north-central coast, established New Zealand Christmas tree in loam needs a deep soak only about once a month or less: about 55 gallons each time under a 10 foot canopy. New Zealand Christmas tree, or pohutukawa, is an evergreen coastal tree with leathery, dark olive leaves that are white and hairy beneath. In late spring and summer it carries brushlike clusters of scarlet flowers with prominent stamens. It thrives in seaside conditions and wants full sun and well-drained soil.

TreeRated for 3 of 6 zones

How often to water New Zealand Christmas 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 New Zealand Christmas 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 6 inches down at the canopy edge tells you New Zealand Christmas tree needs a deep soak
  • Leathery leaves that dull and droop in an inland heat wave can follow dry soil
  • Frost-blackened leaves after a freeze below about 25 degrees show cold damage, not thirst
  • Yellowing leaves over soil that stays wet point to poor drainage around the roots
  • Few new shoots through a long dry summer suggest the tree needs deeper soakings

How to water it

  • Water New Zealand Christmas tree over the root zone under the canopy with drip or a slow soaker
  • Soak 18 inches deep, then let the top several inches dry before the next watering
  • Plant it in full sun or part shade in well-drained, neutral to alkaline soil
  • Mulch the root area with wood chips, keeping them off the trunks
  • Move emitters outward as the multi-trunked canopy widens toward 15 to 20 feet

Through the seasons

Water a new New Zealand Christmas tree regularly through its first summer while roots spread. On the north-central coast, established trees handle dry spells well, while south coast and inland trees need steadier summer checks. The tree is evergreen and flowers in late spring and summer. Irrigation matters most from late spring through fall. Coastal winter rain usually covers the cool months. WUCOLS rates New Zealand Christmas tree low water on the north-central coast. It rates moderate water on the south coast and in South Inland. WUCOLS marks it as not suited to the Central Valley, the high desert or the low desert.

In pots

Young New Zealand Christmas trees, and compact forms, can grow in large containers for some years. Use a pot with drainage holes and a mix that drains well. Check 2 inches down every few days in summer heat, and water when dry. Let water run out the bottom, then empty the saucer. Bring a potted tree under cover when frost below about 28 degrees is forecast, since its roots are more exposed than in the ground.

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

WUCOLS lists New Zealand Christmas 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

New Zealand Christmas Tree: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.15–0.780.78––
Feb0.21–0.810.87––
Mar0.35–1.151.3––
Apr0.47–1.41.61––
May0.58–1.611.95––
Jun0.64–1.742.29––
Jul0.64–1.982.51––
Aug0.6–1.862.33––
Sep0.5–1.491.86––
Oct0.35–1.151.33––
Nov0.19–0.840.9––
Dec0.12–0.650.68––
Year4.8–15.518.41––

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 New Zealand Christmas 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 ratingPurple Orchid TreeBauhinia variegata (purpurea)not 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 rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes New Zealand Christmas 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 New Zealand Christmas tree in summer?

In July, established New Zealand Christmas 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 New Zealand Christmas tree need per day?

In July on the north-central coast, established New Zealand Christmas tree needs about 1.6 gallons a day under a 10 foot canopy and about 6.5 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 New Zealand Christmas tree change across California?

Yes. WUCOLS rates New Zealand Christmas tree separately for each of the six California climate zones: low water 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, 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.

Is New Zealand Christmas tree good near the ocean?

Yes. It does well in seaside conditions and grows wild along the coast of New Zealand's North Island. Near the ocean it needs the least summer water.

How cold can New Zealand Christmas tree take?

It is hardy to about 25 to 30 degrees. Young trees are more tender, so cover them on frosty nights.

How big does New Zealand Christmas tree get?

It usually grows 20 to 35 feet tall and 15 to 20 feet wide, often with several trunks. Plant it well away from walls, and plan irrigation for the full width of the canopy.

Can you overwater New Zealand Christmas tree?

Yes. It needs well-drained soil, and roots kept wet can decline. Let the soil dry several inches down between soakings, especially in winter.

What flower colors does it come in?

Most trees bloom bright red, and pink, yellow or white forms also exist. Flower color does not change its water needs.

More plant watering guides

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Sources