WateringTimesWatering plan, $19
Pinus radiata, WUCOLS IV

How often to water Monterey pine in California

In July on the north-central coast, established Monterey pine in loam needs a deep watering about every 13 days: about 55 gallons each time under a 10 foot canopy, about 29 gallons a week. Monterey pine is a fast-growing California native conifer from a few foggy groves on the central coast. It grows quickly into a tall, dark green tree and tolerates wind and sandy soil. Away from the coastal fog belt, summer heat and dry air stress it, and stressed pines draw bark beetles.

TreeCalifornia nativeRated for 3 of 6 zones

How often to water Monterey 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 Monterey 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

  • Soil dry 4 to 6 inches down at the edge of a young Monterey pine's root ball means it needs a deep soak
  • Needles fading to a dull yellow-green across the crown in a hot, dry spell can point to drought stress
  • Pitch tubes, small blobs of resin on the lower trunk, mean red turpentine beetles are attacking a stressed tree
  • Branch tips wilting, with needles yellowing then browning and resin oozing at the spot, point to pitch canker rather than thirst
  • Yellowing needles over soil kept wet by lawn sprinklers near the trunk signal water in the wrong place

How to water it

  • Water a young tree over the root ball and beyond it, then shift water out to the canopy edge as it grows
  • Soak deeply and seldom so water reaches at least a foot down, instead of giving light lawn-style sprinkles
  • Keep sprinkler spray and emitters away from the trunk
  • Plant it in full sun in sandy or loamy soil that drains
  • Leave fallen needles as mulch over the root zone, clear of the trunk base

Through the seasons

Water a new Monterey pine deeply through its first two or three dry seasons, widening coverage as roots spread. Established coastal trees often get by on winter rain and summer fog. In the dry summers of drought years, deep soakings help them resist bark beetles. Inland, summer heat and dry air add stress, so soil checks matter more there. WUCOLS rates Monterey pine moderate water on the north-central coast, on the south coast and in South Inland. WUCOLS marks it as not suited to the low desert, the high desert or the Central Valley.

In pots

A Monterey pine seedling grows fast and soon outgrows a pot, so plant it out while young. Check a nursery container 2 inches down every few days in summer, and soak it until water drains through. Empty the saucer each time. A black pot in hot sun heats and dries quickly, which stresses this fog-belt tree, so keep it in light shade until planting. In winter, coastal rain may keep the pot moist, so feel the mix before adding water.

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

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

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.37–0.780.78––
Feb0.53–0.810.87––
Mar0.87–1.151.3––
Apr1.18–1.41.61––
May1.46–1.611.95––
Jun1.61–1.742.29––
Jul1.61–1.982.51––
Aug1.49–1.862.33––
Sep1.24–1.491.86––
Oct0.87–1.151.33––
Nov0.47–0.840.9––
Dec0.31–0.650.68––
Year12–15.518.41––

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 Monterey pine. 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 Monterey 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 Monterey pine in summer?

In July, established Monterey 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 Monterey pine need per day?

In July on the north-central coast, established Monterey pine needs about 4.1 gallons a day under a 10 foot canopy and about 16 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 Monterey pine change across California?

Yes. WUCOLS rates Monterey pine separately for each of the six California climate zones: moderate 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.

Why is my Monterey pine dying from the branch tips?

Pitch canker, bark beetles and drought stress are the usual causes, often together. Resin at wilted branch tips points to pitch canker, while pitch tubes on the trunk point to beetles. Deep summer watering in dry years lowers stress but will not cure an infection.

Can Monterey pine grow inland?

It is native to the coastal fog belt and handles inland heat poorly. Inland trees often grow well at first, then decline within several years where summers are hot and dry. For the Central Valley, WUCOLS lists it as not suited.

What are the blobs of sap on my Monterey pine's trunk?

They are likely pitch tubes from red turpentine beetles, which are common on landscape Monterey pines. An attack usually means the tree is under stress. Deep watering at the canopy edge in dry summers helps, and an arborist can confirm the cause.

Should I prune a Monterey pine with pitch canker?

Removing branches with a few early infections can clear the disease from a lightly affected tree. Some infected trees recover on their own. Take a cautious approach before removing a whole tree.

Does an established Monterey pine need summer water on the coast?

Trees in the fog belt often need little. In dry summers of drought years, a deep soak around the outer canopy helps them fend off bark beetles. Keep that water away from the trunk.

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Sources