WateringTimesWatering plan, $19
Pinellia ternata, WUCOLS IV

How often to water pinellia in California

In July on the north-central coast, established pinellia in loam needs a deep watering about every 9 days: about 1.5 gallons each time for a plant 2 feet across, about 1.1 gallons a week. Pinellia, also called crowdipper or green dragon, is a small perennial from East Asia related to jack-in-the-pulpit. Its flowers are a green, hooded spathe around a long spadix. It spreads by bulbils halfway up the leaf stalks, by corms on creeping rhizomes and by seed. Once it settles in a bed, it is very hard to remove.

PerennialRated for 3 of 6 zones

How often to water pinellia, 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 pinellia 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 foot 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 around the leaves in summer means pinellia can take water
  • Leaves flopping in afternoon heat can point to a dry root zone
  • Leaves browning at the tips in a hot spell can follow dry soil
  • Small round bulbils on the leaf stalks are its normal way of spreading, not a problem with water

How to water it

  • Water at the base of the leaves with a gentle hose or drip
  • Wet the soil 4 to 6 inches deep, then let the top inch or two dry
  • Grow it in a pot or a bed edged deeply to contain the rhizomes
  • Pick off bulbils before they drop to the soil
  • Remove ripening flower spikes to stop seed

Through the seasons

Water pinellia while its leaves are growing and rain falls short, letting the top inch dry between drinks. Bulbils that fall stay dormant in the soil until the next season, so new plants can appear far from the parent. Even removing leaves does not stop fast regrowth from the corms. WUCOLS rates pinellia moderate water on the north-central coast and the south coast. South Inland carries a low water rating. WUCOLS has not evaluated it for the Central Valley, the high desert or the low desert.

In pots

A pot is the safest home for pinellia, since it keeps the spreading corms out of garden beds. Use a well-drained mix. Water when the top inch dries, until it runs through. In warm weather, a small pot may need water every few days. Empty the saucer. Pick bulbils off the leaf stalks and throw them in the trash. In cool months, water only when the mix dries.

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

WUCOLS lists Pinellia as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Pinellia: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.37–0.780.31––
Feb0.53–0.810.35––
Mar0.87–1.150.52––
Apr1.18–1.40.64––
May1.46–1.610.78––
Jun1.61–1.740.92––
Jul1.61–1.981––
Aug1.49–1.860.93––
Sep1.24–1.490.74––
Oct0.87–1.150.53––
Nov0.47–0.840.36––
Dec0.31–0.650.27––
Year12–15.57.37––

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 not evaluated in the Central Valley, like pinellia. Plants that drink alike can share one valve and one schedule.

Lilyleaf LadybellsAdenophora liliifolianot rated, Central Valleyno Central Valley ratingArnicaArnica montananot rated, Central Valleyno Central Valley ratingFrilly BergeniaBergenia ciliatanot rated, Central Valleyno Central Valley ratingCabbage on a StickBrighamia insignisnot rated, Central Valleyno Central Valley ratingBasket PlantCallisia fragransnot rated, Central Valleyno Central Valley ratingForest SedgeCarex sylvaticanot rated, Central Valleyno Central Valley ratingUmbrella DracaenaDianella ensifolianot rated, Central Valleyno Central Valley ratingRusty FoxgloveDigitalis ferrugineanot rated, Central Valleyno Central Valley ratingBig-Flowered FoxgloveDigitalis grandifloranot rated, Central Valleyno Central Valley ratingWoolly FoxgloveDigitalis lanatanot rated, Central Valleyno Central Valley ratingSunset FoxgloveDigitalis obscuranot rated, Central Valleyno Central Valley ratingMale FernDryopteris filix-masnot rated, Central Valleyno Central Valley ratingAlpine Sea HollyEryngium alpinumnot rated, Central Valleyno Central Valley ratingPurple SpurgeEuphorbia dulcisnot rated, Central Valleyno Central Valley ratingQueen of the MeadowFilipendula ulmarianot rated, Central Valleyno Central Valley ratingDropwortFilipendula vulgaris (Filipendula hexapetala)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 pinellia, 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 pinellia in summer?

In July, established pinellia in loam needs a deep watering about every 7 days on the south coast and about every 14 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 pinellia need per day?

In July on the north-central coast, established pinellia 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 pinellia change across California?

Yes. WUCOLS rates pinellia 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, low 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.

Is pinellia invasive?

It is a triple threat in a garden, spreading three different ways. Once established it is nearly impossible to eradicate. Keep it in a pot.

Is pinellia poisonous?

Yes, its corms are poisonous. Keep it away from children and pets. Wear gloves when handling corms.

What are the little bulbs on pinellia stems?

They are bulbils, small aerial tubers that form halfway up the leaf stalks. They harden, fall and sprout the next season. Pick them off to slow its spread.

What is pinellia related to?

It is related to jack-in-the-pulpit but smaller and less showy. Its green, hooded flowers give it the name green dragon. Many gardeners treat it as a weed.

How do I get rid of pinellia?

Dig out corms and rhizomes carefully, and remove every leaf with bulbils. Expect regrowth for more than one season. Check the spot again each spring.

More plant watering guides

Everglades PalmPink CedarVariegated KiwiLilyleaf LadybellsYellowwoodNew Caledonian PineFormosa Sugar PalmArnica

Sources