WateringTimesWatering plan, $19
Araucaria columnaris (A. cookii), WUCOLS IV

How often to water New Caledonian pine in California

In July on the north-central coast, established New Caledonian pine in loam needs a deep watering about every 8 days: about 55 gallons each time under a 10 foot canopy, about 46 gallons a week. New Caledonian pine, also called Cook pine, is a tall, narrow conifer from New Caledonia that grows into a slender column. Each tree leans, and in the Northern Hemisphere the lean points south. It is often confused with Norfolk Island pine, suits warm, mild climates, and is prone to root rot in soggy soil.

TreeRated for 3 of 6 zones

How often to water New Caledonian pine, 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 Caledonian pine 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 young Cook pine needs a deep soak once the soil at the edge of its root ball is dry 4 to 6 inches down
  • Lower branches browning on a young tree in summer heat can follow a dry root zone
  • Yellowing growth and a soft trunk base in soggy soil point to root rot, a known problem for this tree
  • A trunk that tilts toward the south is the species' normal lean, not a sign of weak roots or uneven watering

How to water it

  • Water a young tree slowly with drip or a soaker over its root ball and a ring beyond it
  • Soak the soil about 18 inches deep, letting the top several inches dry before the next soak
  • Plant it in well-drained soil where water never stands, mounding heavy clay
  • Keep the trunk base dry and move emitters outward as the tree grows
  • Choose a site with plenty of vertical room, since it can reach 90 feet while staying narrow

Through the seasons

Plan on deep soakings for a newly planted New Caledonian pine over its first few summers, until roots grow well past the planting hole. Older trees still want a deep summer soak whenever the top several inches dry. It stays evergreen and grows steadily into a narrow column. Coastal rain usually covers the cool months. WUCOLS rates New Caledonian pine high water on the north-central coast and moderate water on the south coast and in South Inland. WUCOLS has not evaluated it for the Central Valley and marks it as not suited to the high desert or the low desert.

In pots

Young New Caledonian pines are sometimes sold as potted plants, and they can live in a large container for a few years. Feel the mix about 2 inches down every few days in summer, and water through the pot when it feels dry. Empty the saucer right away, since soggy mix invites root rot. In winter, water less and let the mix dry a little more between waterings. Plant it out in the ground before it becomes top-heavy in the pot.

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

WUCOLS lists New Caledonian Pine as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

New Caledonian Pine: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.6–0.780.78––
Feb0.84–0.810.87––
Mar1.39–1.151.3––
Apr1.88–1.41.61––
May2.33–1.611.95––
Jun2.58–1.742.29––
Jul2.58–1.982.51––
Aug2.38–1.862.33––
Sep1.98–1.491.86––
Oct1.39–1.151.33––
Nov0.74–0.840.9––
Dec0.5–0.650.68––
Year19.2–15.518.41––

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 evaluated in the Central Valley, like New Caledonian pine. Plants that drink alike can share one valve and one schedule.

Hawthorn MapleAcer crataegifoliumnot rated, Central Valleyno Central Valley ratingMountain MapleAcer glabrumnot rated, Central Valleyno Central Valley ratingMiyabe MapleAcer miyabeinot rated, Central Valleyno Central Valley ratingEverglades PalmAcoelorraphe wrightiinot rated, Central Valleyno Central Valley ratingPink CedarAcrocarpus fraxinifoliusnot rated, Central Valleyno Central Valley ratingYellowwoodAfrocarpus falcatus (Podocarpus falcatus)not rated, Central Valleyno Central Valley ratingFormosa Sugar PalmArenga englerinot rated, Central Valleyno Central Valley ratingNeemAzadirachta indicanot rated, Central Valleyno Central Valley ratingBismarck PalmBismarckia nobilisnot rated, Central Valleyno Central Valley ratingAmerican HornbeamCarpinus caroliniananot rated, Central Valleyno Central Valley ratingJapanese HornbeamCarpinus japonicanot rated, Central Valleyno Central Valley ratingAmerican YellowwoodCladrastis kentukeanot rated, Central Valleyno Central Valley ratingPagoda DogwoodCornus alternifolianot rated, Central Valleyno Central Valley ratingGiant DogwoodCornus controversanot rated, Central Valleyno Central Valley ratingButterfly PalmDypsis lutescens (Areca)not rated, Central Valleyno Central Valley ratingAbyssinian Coral TreeErythrina abyssinicanot 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 Caledonian pine, 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 Caledonian pine in summer?

In July, established New Caledonian pine 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 Caledonian pine need per day?

In July on the north-central coast, established New Caledonian pine needs about 6.5 gallons a day under a 10 foot canopy and about 26 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 Caledonian pine change across California?

Yes. WUCOLS rates New Caledonian pine separately for each of the six California climate zones: high water in the North-Central Coastal zone, not evaluated 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.

Why is my Cook pine leaning?

Every tree of this species leans, and north of the equator the tilt runs toward the south. It is a natural trait, not a sign of weak roots. Watering has nothing to do with it.

Is New Caledonian pine the same as Norfolk Island pine?

No. They are often confused, but Norfolk Island pine is a different species, Araucaria heterophylla. Check the nursery label if you need to know which one you have.

How tall does New Caledonian pine get?

In landscapes it can reach about 90 feet while staying around 20 feet wide. Give it vertical room away from power lines.

Does New Caledonian pine tolerate salt?

It has moderate salt tolerance, so it handles some coastal exposure. A long, slow soak now and then moves salt below the roots.

Why are the roots rotting on my Cook pine?

Root rot is a known problem for this tree, usually in soil that stays wet. Improve drainage, let the soil dry a little between soakings, and keep sprinklers off the trunk base.

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Sources