WateringTimesWatering plan, $19
Ilex crenata, WUCOLS IV

How often to water box-leaved holly in California

In July on the north-central coast, established box-leaved holly in loam needs a deep watering about every 13 days: about 8.8 gallons each time for a plant 4 feet across, about 4.6 gallons a week. Box-leaved holly, also called Japanese holly, is a dense, rounded evergreen shrub from Japan and East Asia with small, glossy leaves. It grows slowly to 5 to 10 feet, while many cultivars stay 3 to 4 feet, and it takes hard pruning well. It wants acidic, well-drained soil in sun or part shade and tolerates drought, clay and shade.

ShrubRated for 3 of 6 zones

How often to water box-leaved holly, month by month

Your city
Plant width
4 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 box-leaved holly 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 the plant covers, 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 plant width

A shrub with its width marked from one side to the other and the circle under it shaded blue

Measure across the plant, from the tips of the leaves on one side to the tips on the other.

Water the whole area the plant covers, shown in blue. The gallons here cover that area.

A wider plant means more gallons each watering, not more waterings. While it is young, measure again each spring.

How to tell it needs water

  • Soil dry 3 inches down under the shrub in summer signals box-leaved holly wants a soak
  • Leaves losing their gloss and drooping in afternoon heat can indicate thirst
  • Leaves yellowing between green veins point to soil that is not acidic enough
  • Inner leaves yellowing and dropping over soggy soil suggest poor drainage

How to water it

  • Water the root zone with drip or a soaker
  • Soak about a foot down, then let the top few inches dry
  • Plant in acidic, well-drained soil in full sun to part shade
  • Mulch to keep roots cool and slow evaporation
  • Shear or prune to shape, since it takes severe pruning

Through the seasons

Water a new shrub regularly through its first summer. Established plants tolerate some drought but stay denser and greener with moderate, deep watering in dry months. It is evergreen, with small flowers and, on female plants near a male, black berries in fall. WUCOLS rates box-leaved holly moderate water on the north-central coast, the south coast and South Inland. WUCOLS has not evaluated it for the Central Valley, the high desert or the low desert.

In pots

Box-leaved holly suits containers, small hedges in planters and topiary. Use an acidic, well-drained mix. Water when the top couple of inches feel dry, and soak until it flows from the drainage holes. In summer, check pots every few days, and daily in hot sun. Do not let the pot sit in water. In winter, water when the mix dries and rain falls short.

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

WUCOLS lists Box-leaved Holly as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Box-leaved Holly: 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 evaluated in the Central Valley, like box-leaved holly. Plants that drink alike can share one valve and one schedule.

Formosa Sugar PalmArenga englerinot rated, Central Valleyno Central Valley ratingChilean Feather BambooChusquea culeou (C. breviglumis)not rated, Central Valleyno Central Valley ratingBlackbrushColeogyne ramosissimanot rated, Central Valleyno Central Valley ratingGlaucous Scorpion VetchCoronilla valentina glaucanot rated, Central Valleyno Central Valley ratingWillowleaf CotoneasterCotoneaster salicifoliusnot rated, Central Valleyno Central Valley ratingMadagascar SagoCycas thouarsii (SHADE)not rated, Central Valleyno Central Valley ratingIrish HeathDaboecia cantabricanot rated, Central Valleyno Central Valley ratingButterfly PalmDypsis lutescens (Areca)not rated, Central Valleyno Central Valley ratingUmbrella BambooFargesia murielaenot rated, Central Valleyno Central Valley ratingBlue Fountain BambooFargesia nitida (Sinarundinaria nitida) (BAMBOO)not rated, Central Valleyno Central Valley ratingPrickly HeathGaultheria mucronata (Pernettya mucronata)not rated, Central Valleyno Central Valley ratingOtterbossieGossypium harknessiinot rated, Central Valleyno Central Valley ratingBellyache BushJatropha gossypiifolianot rated, Central Valleyno Central Valley ratingMountain LaurelKalmia latifolianot rated, Central Valleyno Central Valley ratingBarbados CherryMalpighia glabranot rated, Central Valleyno Central Valley ratingSiberian CypressMicrobiota decussatanot 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 box-leaved holly, 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 box-leaved holly in summer?

In July, established box-leaved holly 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 box-leaved holly need per day?

In July on the north-central coast, established box-leaved holly needs about 0.7 gallons a day for a plant 4 feet across and about 2.6 gallons a day for a plant 8 feet across. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Does watering for box-leaved holly change across California?

Yes. WUCOLS rates box-leaved holly separately for each of the six California climate zones: moderate 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 evaluated in the High and Intermediate Desert zone, not evaluated in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Why doesn't my box-leaved holly have berries?

Male and female flowers grow on separate plants. A female needs a male nearby to set its black berries. Many cultivars are sold for foliage, not fruit.

Is box-leaved holly good for hedges?

Yes, it works as a hedge, border, foundation planting or topiary. It can be severely pruned to keep it small. It needs acidic soil to look its best.

How big does box-leaved holly get?

The species slowly reaches 5 to 10 feet. Many cultivars stay 3 to 4 feet. Severe pruning keeps it small.

Does box-leaved holly handle heat?

It may not thrive in high heat with humidity. In hot inland gardens, watch the soil closely in summer. Shelter it from cold, drying winds.

Is box-leaved holly poisonous?

It has low severity poison characteristics. Keep children and pets from eating the berries. Wear gloves when pruning.

More plant watering guides

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Sources