WateringTimesWatering plan, $19
Paeonia spp. & cvs., WUCOLS IV

How often to water peony in California

In July in the Central Valley, established peony in loam needs a deep watering about every 5 days: about 1.5 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Peonies are long-lived perennials, and some are deciduous shrubs, with large, divided leaves and showy, bowl-shaped flowers, usually in late spring or early summer. Herbaceous kinds die back each fall and return from fleshy roots. They want full sun and deep, rich soil that drains, and once established their deep roots need little routine watering.

PerennialRated for 2 of 6 zones

How often to water peony, 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 peony 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 4 inches down beside the clump during spring growth signals peony needs water
  • Leaves wilting in afternoon heat while buds are forming can indicate thirst
  • Buds failing to open after a dry spring can follow a dry root zone
  • Stems wilting and blackening at the base in waterlogged soil point to rot

How to water it

  • Water the root zone deeply in dry spells, especially in the first year
  • Soak about a foot down, then let the soil dry well before the next soak
  • Plant in full sun in deep, rich soil that does not waterlog
  • Set the red buds no more than an inch below the soil surface
  • Mulch with organic matter in late autumn or winter

Through the seasons

Water a newly planted peony regularly in dry spells through its first year. After that, established peonies are deep-rooted and need little routine watering in mild weather, with deep soaks in long dry spells. Herbaceous kinds die back in fall and rest through winter, then flower in late spring or early summer. On the north-central coast and in the Central Valley, WUCOLS gives peony a moderate water rating. WUCOLS marks it as not suited to the south coast, the high desert or the low desert, and has not evaluated it for South Inland.

In pots

Peonies grow best in the ground, but a herbaceous peony can live in a large, deep pot. Use a rich, well-drained mix. Water in spring and summer when the top couple of inches dry, letting it drain fully. Empty the saucer after each watering. Cut back dead stems in autumn. In winter, water rarely while the plant rests, and keep the pot where water does not collect.

1 Your climate zone six WUCOLS zones, each from its own reference city
2.67gal per sq ft in JulyModerate water use in the Central Valley zone
A year
17.11 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.671.32.02.70.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.671.32.02.70.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.4––––
Feb0.530.65––––
Mar0.871.09––––
Apr1.181.52––––
May1.462.08––––
Jun1.612.48––––
Jul1.612.67––––
Aug1.492.39––––
Sep1.241.8––––
Oct0.871.18––––
Nov0.470.56––––
Dec0.310.34––––
Year1217.11––––

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 moderate water in the Central Valley, like peony. Plants that drink alike can share one valve and one schedule.

Similar plants that need less water 16

Rated lower than peony in the Central Valley. Worth a look for a new bed or a lawn replacement.

Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes peony, 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 peony need per day?

In July in the Central Valley, established peony needs about 0.3 gallons a day for a plant 2 feet across and about 1.1 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 peony change across California?

Yes. WUCOLS rates peony separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, moderate water in the Central Valley zone, not suited to this region in the South Coastal zone, not evaluated 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 won't my peony bloom?

Planting too deep is a common cause, since buds should sit no more than about an inch below the surface. Too much shade also reduces bloom. Give it full sun.

Do peonies need much water?

Water regularly in the first year. After that, their deep roots need little routine watering. Soak deeply in long dry spells.

When should I cut back peonies?

Cut dead stems of herbaceous peonies back in autumn. Mulch afterward. New shoots return in spring.

When should I plant peonies?

Potted plants are best planted in late spring, and bare-root divisions in late autumn. Set buds shallow. Water well after planting.

Can peonies grow in clay?

Yes, as long as the soil does not get waterlogged. Dig in compost before planting. Raised beds help in heavy clay.

More plant watering guides

Sources