WateringTimesWatering plan, $19
Ardisia japonica, WUCOLS IV

How often to water Japanese ardisia in California

In July on the north-central coast, established Japanese ardisia in loam needs a deep watering about every 13 days: about 2.2 gallons each time for a plant 2 feet across, about 1.1 gallons a week. Japanese ardisia is a low, evergreen woody groundcover from East Asian forests, under a foot tall, with glossy, leathery leaves bunched at the stem tips. It spreads by underground runners into a dense mat for shady ground. It wants soil that stays moist but drains, since it handles neither drought nor flooding.

Ground coverRated for 2 of 6 zones

How often to water Japanese ardisia, month by month

Your city
Plant width
2 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 Japanese ardisia 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 2 inches down beneath the mat means Japanese ardisia is ready for water, since it does not handle dry ground
  • Glossy leaves that hang limp in the afternoon and are still limp the next morning can point to a dry root zone
  • Brown, scorched leaves on the sunniest side of the bed point to too much sun, which burns this shade plant even in moist soil
  • Yellowing stems over soil that stays soggy after rain or long irrigation runs point to wet ground, which this groundcover should not sit in
  • Copper or bronze new growth in spring is the plant's normal coloring and is not a sign of thirst

How to water it

  • Water the whole planted bed with drip line or low spray heads, since the underground runners spread across the area
  • Soak the soil about 6 inches deep, then water again when the top inch or two begins to dry
  • Work compost into the bed before planting and top it with leaf mulch, since this plant prefers soil rich in organic matter
  • Plant in acidic, well-drained soil, and avoid low spots where water stands after winter storms
  • Extend drip coverage as the runners spread so the new outer edges of the colony get water too

Through the seasons

Water a new planting of Japanese ardisia evenly through its first summer, until the runners start to fill the gaps between plants. Established mats still need steady moisture, since this groundcover does not tolerate drought. It stays evergreen all year, with small white to pale pink flowers in July and August and red berries in fall. Summer and early fall are when irrigation matters most. Winter rain covers the cool months along the coast, though long dry winter spells call for a soil check. WUCOLS rates it moderate water on the north-central coast and high water on the south coast. WUCOLS marks it as not suited to the Central Valley, South Inland, the high desert or the low desert.

In pots

Japanese ardisia can be grown in a container, which also keeps its runners from wandering through a bed. Use a wide, shallow pot with a rich, acidic mix and open drainage holes. Check the mix an inch down every few days in summer, and keep the pot in shade, since direct sun burns the leaves. Water until it drains from the holes, then empty the saucer so the roots never sit in water. In winter, check the mix before watering, since rain and cool weather slow drying.

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

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

Monthly water need by climate zone

Japanese Ardisia: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.37–1.24–––
Feb0.53–1.29–––
Mar0.87–1.84–––
Apr1.18–2.23–––
May1.46–2.58–––
Jun1.61–2.78–––
Jul1.61–3.17–––
Aug1.49–2.98–––
Sep1.24–2.38–––
Oct0.87–1.84–––
Nov0.47–1.34–––
Dec0.31–1.04–––
Year12–24.8–––

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 4

Rated not suited to this region in the Central Valley, like Japanese ardisia. Plants that drink alike can share one valve and one schedule.

Swedish IvyPlectranthus verticillatusnot rated, Central Valleyno Central Valley ratingWhite CloverTrifolium repensnot rated, Central Valleyno Central Valley ratingCoral VineAntigonon leptopusnot rated, Central Valleyno Central Valley ratingProstrate Natal PlumCarissa macrocarpa 'Prostrata'not 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 Japanese ardisia, 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 much water does Japanese ardisia need per day?

In July on the north-central coast, established Japanese ardisia needs about 0.2 gallons a day for a plant 2 feet across and about 0.7 gallons a day for a plant 4 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 Japanese ardisia change across California?

Yes. WUCOLS rates Japanese ardisia 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, high water in the South Coastal zone, not suited to this region 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.

Will Japanese ardisia grow in full sun?

No, it is a plant for part shade to full shade. Too much sun burns the leaves, and extra water does not prevent the scorch. Move it under trees or to the shady side of a building.

Does Japanese ardisia spread?

Yes. It spreads by underground runners and can form large colonies over time. It also seeds itself freely and can escape into nearby areas, so watch the edges of the bed.

Can you walk on Japanese ardisia?

No. It does not tolerate foot traffic. Lay stepping stones through a large planting instead of walking across the mat.

When does Japanese ardisia flower?

Small white to pale pink, star-shaped flowers open in July and August. They form under the leaves and are easy to miss. Small red berries follow in fall.

How cold hardy is Japanese ardisia?

It is rated hardy in USDA zones 8 to 10. Variegated forms tend to be less cold hardy than plain green ones. Choose a green form where winter nights get cold.

Does Japanese ardisia need acidic soil?

It prefers acidic soil rich in organic matter. Where the ground is alkaline, work in compost before planting and keep a leaf mulch over the bed. A large pot of acidic mix is the simpler choice in very alkaline soil.

More plant watering guides

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Sources