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WateringTimes

Citrus spp. · WUCOLS

How Often to Water Citrus Trees in California

Computed August 26, 2026 from WUCOLS and adopted state reference data

Established citrus trees rate as moderate water plants in the Central Valley: about 2.67 gallons per square foot in July and 17.11 gallons per square foot per year, before irrigation losses. Citrus trees are evergreen and use a moderate amount of water all year, more than a tough native shrub but far less than a lawn. They fruit best on deep, steady soakings that let the soil dry slightly in between, and they resent soggy ground around the trunk. Uneven watering shows up quickly in the crop as fruit drop, split fruit, and dry pulp.

Your climate zone

Citrus Trees: moderate water use in the Central Valley zone

About 2.67 gallons per square foot in July and 17.11 gallons per square foot over a full year, using Sacramento as the zone reference city. These are plant needs before irrigation system losses.

Monthly water need by climate zone

Citrus Trees: gallons per square foot per month, by WUCOLS climate zone

Six climate zones, one row per month. The table scrolls sideways on a narrow screen; the month column stays put.

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.78–0.78
Feb0.530.650.810.87–0.93
Mar0.871.091.151.3–1.52
Apr1.181.521.41.61–1.95
May1.462.081.611.95–2.45
Jun1.612.481.742.29–2.79
Jul1.612.671.982.51–2.85
Aug1.492.391.862.33–2.6
Sep1.241.81.491.86–2.08
Oct0.871.181.151.33–1.49
Nov0.470.560.840.9–0.96
Dec0.310.340.650.68–0.68

Computed as the WUCOLS class midpoint for Citrus spp. times monthly reference evapotranspiration for each zone's reference city (N. Coast: San Francisco, C. Valley: Sacramento, S. Coast: Los Angeles, S. Inland: Riverside, Hi Desert: Victorville, Lo Desert: Palm Springs) times 0.62. A dash means WUCOLS does not rate this plant for that zone. Values are plant needs before irrigation system losses. Cool-season values are usually covered by rain, and dormant or deciduous plants often need no irrigation at all in winter; see Through the seasons below.

How to tell it needs water

  • Soil dry 2 to 3 inches down under the canopy means an established tree is ready for a deep soak
  • Leaves that fold inward along the midrib in afternoon heat and are still folded the next morning signal real thirst
  • Dull, grayish foliage that has lost its gloss is an early thirst cue that shows up before any wilting
  • Yellowing leaves that drop while the soil is still damp point to overwatering or poor drainage, not thirst
  • Split fruit or a sudden shower of small green fruit usually means swings between bone dry and soaked, so steady the rhythm rather than adding more water

How to water it

  1. Water the whole area under the canopy out past the edge of the branches, and keep the trunk itself dry
  2. Use a ring of drip emitters or a slow hose in a shallow soil basin so water sinks deep instead of running off
  3. Soak deeply, then let the surface dry slightly before the next round; citrus feeder roots sit near the surface and need air as much as water
  4. Spread wood-chip mulch under the canopy, pulled back from the trunk, to slow evaporation
  5. As the tree grows, move emitters outward so the water follows the expanding root zone

In pots

Dwarf citrus in a container needs closer attention than any in-ground tree. Pots dry fast in warm weather, so check the top couple of inches of mix often and water thoroughly whenever they feel dry, until water runs from the drainage holes. Never let the pot stand in a saucer of water, because citrus roots rot quickly without air. Steady moisture matters even more in a pot than in the ground: big wet-dry swings make container citrus drop leaves, flowers, and young fruit.

Through the seasons

A young citrus tree has a small root system and needs consistent moisture through its first few summers, checked often and never allowed to bake dry. A mature tree shifts to deep, less frequent soakings. Across coastal and valley California, irrigation matters most from late spring through early fall while fruit is sizing, then tapers as the days cool. Citrus stays evergreen through winter and never goes fully dormant, so it keeps drinking a little in the cool months. Winter rain usually covers that in much of the state, but keep watering through long dry winter spells, especially in the deserts.

Questions people ask

How much water do citrus trees need in summer?
In July, an established planting needs roughly this many gallons per square foot: 1.61 in the North-Central Coastal zone, 2.67 in the Central Valley zone, 1.98 in the South Coastal zone, 2.51 in the South Inland zone, 2.85 in the Low Desert zone. Figures are computed from the WUCOLS rating for Citrus spp. and each zone's reference evapotranspiration, and they are plant needs before irrigation system losses.
Does watering for citrus trees change across California?
Yes. WUCOLS rates citrus trees separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, moderate water 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.
Can you overwater a citrus tree?
Yes, and it is one of the most common ways home citrus fails. Constantly wet soil suffocates the shallow feeder roots and invites root rot: leaves yellow and drop even though the soil is damp, and bark near the soil line can darken. Let the surface dry slightly between soakings and keep water off the trunk.
How should I water a newly planted citrus tree?
For the first season the tree can only drink from its original root ball, so water right over it and keep it evenly moist through the first summer. Check it often in warm weather, since a small root ball dries much faster than the surrounding soil. As the tree establishes, widen the watered area and shift toward deeper, less frequent soakings.
Is drip irrigation good for citrus trees?
Drip works very well as long as it covers enough ground. A single emitter next to the trunk is not enough for a tree; use a ring or grid of emitters under the canopy and move them outward as the tree grows. Run the system long enough for water to sink deep into the root zone instead of just wetting the surface.
Why are my citrus tree's leaves turning yellow?
Check the soil before reaching for fertilizer. Soggy, poorly drained soil yellows citrus leaves and makes them drop, and cold wet winter soil can trigger yellowing between the veins even when nutrients are fine. If the soil is drying properly between waterings and the yellowing continues into warm weather, a nitrogen or iron shortage becomes the more likely cause.
Why is my citrus tree dropping fruit?
Some drop is normal: citrus sets far more fruit than it can carry and sheds the extras in late spring. Heavy drop beyond that, or fruit that splits in late summer and fall, usually traces back to moisture swings, long dry spells followed by heavy soakings. Steady, deep watering on a regular rhythm is the fix, not more water overall.
Should I water citrus in winter in California?
Citrus is evergreen and keeps drinking a little all winter, so do not shut the water off completely. In most of the state winter rain covers the need, and irrigation is only for long dry gaps between storms. There is a bonus to not letting the soil go dust dry: moist soil holds daytime warmth and gives the roots some protection on frosty nights.

More plant watering guides

Sources

WateringTimes is an informational gardening and landscape reference for California. Watering numbers are estimates computed from public state data. Nothing on this site is regulatory or professional advice of any kind. Check your water supplier’s current rules before relying on any schedule.