WateringTimesWatering plan, $19
Pinus attenuata, WUCOLS IV

How often to water knobcone pine in California

In July in the Central Valley, established knobcone pine in loam needs a deep watering about every 20 days: about 55 gallons each time under a 10 foot canopy, about 19 gallons a week. Knobcone pine is a fast-growing, often multi-trunked California native of dry, rocky slopes in the coast ranges and Sierra foothills. Its lopsided cones cling tightly to trunk and branches for years and usually open only after fire. It is drought tolerant with a strong tendency to root deeply, and it is relatively short lived.

TreeCalifornia nativeRated for 4 of 6 zones

How often to water knobcone 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 knobcone 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 knobcone pine with soil dry 2 feet down past its branch tips in an early summer is due for a soak
  • Needles yellowing and dropping from the inside during a hot first summer can indicate a dry root ball
  • Pitch tubes or boring dust on the trunk point to bark beetles on a stressed tree
  • Yellowing new growth with soggy soil around the trunk suggests overwatering

How to water it

  • Water a young tree in a wide ring out past the branch tips, keeping the trunk dry
  • Wet the ground deeply, then wait until it has dried well below the surface
  • Plant in full sun in shallow, rocky or sandy soil that drains fast
  • Keep it away from lawns and other frequently watered beds
  • Stop regular watering once the tree is established

Through the seasons

Give a young knobcone pine a few long soaks in its first summer or two so roots chase moisture downward. Established trees are drought tolerant and need little or no summer water. It is evergreen and shade intolerant, so it needs full sun. Winter rain covers its needs on the coast and in the valley. WUCOLS rates knobcone pine very low water on the north-central coast. Inland in the Central Valley, and southward on the south coast and in South Inland, it carries a low water rating. Neither desert suits it, and WUCOLS marks it as not suited to the high desert or the low desert.

In pots

Knobcone pine is a tree for the ground, not a long-term container. A seedling can spend a short time in a deep pot of gritty mix before planting. Water once the mix is dry several inches down, and let it drain completely. In summer heat, check every few days. Empty the saucer every time. Plant it out young, since its deep roots develop quickly. Choose a tall pot to fit the long root.

1 Your climate zone six WUCOLS zones, each from its own reference city
1.07gal per sq ft in JulyLow water use in the Central Valley zone
A year
6.84 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.270.540.801.10.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.270.540.801.10.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.040.160.310.31––
Feb0.050.260.320.35––
Mar0.090.430.460.52––
Apr0.120.610.560.64––
May0.150.830.640.78––
Jun0.160.990.690.92––
Jul0.161.070.791––
Aug0.150.950.740.93––
Sep0.120.720.60.74––
Oct0.090.470.460.53––
Nov0.050.220.330.36––
Dec0.030.140.260.27––
Year1.26.846.27.37––

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 low water in the Central Valley, like knobcone pine. Plants that drink alike can share one valve and one schedule.

Olive 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 JulyAloeAloe 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 JulyTexas Red OakQuercus buckleyilow water, Central Valley1.07 gal/sq ft in JulyPortuguese OakQuercus faginealow water, Central Valley1.07 gal/sq ft in JulySoapbark TreeQuillaja saponarialow water, Central Valley1.07 gal/sq ft in JulyNecklace TreeSophora affinislow water, Central Valley1.07 gal/sq ft in JulyBailey AcaciaAcacia baileyanalow water, Central Valley1.07 gal/sq ft in JulySilver WattleAcacia dealbatalow water, Central Valley1.07 gal/sq ft in JulyGreen WattleAcacia decurrenslow water, Central Valley1.07 gal/sq ft in JulySydney Golden WattleAcacia longifolialow 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 knobcone 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 knobcone pine in summer?

In July, established knobcone pine in loam needs a deep watering about every 20 days in the Central Valley, about every 27 days on the south coast and about every 22 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 knobcone pine need per day?

In July in the Central Valley, established knobcone pine needs about 2.7 gallons a day under a 10 foot canopy and about 11 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 knobcone pine change across California?

Yes. WUCOLS rates knobcone pine separately for each of the six California climate zones: very low water in the North-Central Coastal zone, low water in the Central Valley zone, low water in the South Coastal zone, low 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 don't knobcone pine cones open?

Its cones stay closed for years, even after the tree dies. They usually open only after fire. The seeds then sprout on the burned ground.

How long does knobcone pine live?

Its lifespan is relatively short for a pine. It is a pioneer that grows fast on poor sites. Extra water will not make it live longer.

Can knobcone pine grow in poor soil?

Yes, it grows naturally on shallow, rocky, infertile soils, including serpentine. Poor soil suits it well. Drainage is more important than richness.

Can knobcone pine grow in shade?

No, it is a shade-intolerant pioneer and needs full sun. It does not thrive under other trees. Plant it in an open, sunny spot.

Is knobcone pine native to California?

Yes, it grows in the coast ranges from Oregon into central California, in the Sierra foothills and in scattered southern mountains. It is part of the closed-cone pine forest. It suits native gardens on rocky slopes.

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Sources