WateringTimesWatering plan, $19
Salvia azurea, WUCOLS IV

How often to water prairie sage in California

In July in the Central Valley, established prairie sage 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. Prairie sage, also called blue sage or pitcher sage, is a perennial wildflower native to the South and central United States. Its slender stems reach 3 to 5 feet and carry sky-blue flowers from midsummer into fall that draw bees and butterflies. It likes sandy or rocky soil that drains well, and in rich soil the stems tend to flop.

PerennialRated for 4 of 6 zones

How often to water prairie sage, 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 prairie sage 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

  • A trowel turning up dry soil a few inches down beside prairie sage in summer means it can take water
  • Stems drooping and lower leaves wilting by afternoon suggest a dry root zone
  • Flowering slowing early in late summer heat can follow dry soil
  • Stems sprawling in rich, wet soil point to too much water and fertility, not thirst

How to water it

  • Water deeply at the base, then let the top few inches dry
  • Plant in full sun to part shade in sandy or rocky, well-drained soil
  • Skip compost and fertilizer, which make stems floppy
  • Cut stems back by half in late spring for fuller growth
  • Leave dead stems 12 to 24 inches tall over winter for stem-nesting bees

Through the seasons

Water new plants regularly while they settle in. Established clumps like moist, well-drained soil but put up with occasional dry spells, so moderate summer water keeps them blooming. Flowers run from midsummer into fall, and then the stems die back for winter. Across the north-central coast, the Central Valley, the south coast and South Inland, prairie sage gets a moderate water rating from WUCOLS. Neither desert zone has a WUCOLS evaluation for it.

In pots

Prairie sage can grow in a large, deep pot, though its tall stems need room. Use a lean, gritty mix that drains fast. Water once the top couple of inches are dry, until it runs through. In summer, check every few days. Never leave it standing in water. Cut it back by half in late spring to keep it compact. In winter, after it dies back, water very little.

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

Prairie Sage: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.78––
Feb0.530.650.810.87––
Mar0.871.091.151.3––
Apr1.181.521.41.61––
May1.462.081.611.95––
Jun1.612.481.742.29––
Jul1.612.671.982.51––
Aug1.492.391.862.33––
Sep1.241.81.491.86––
Oct0.871.181.151.33––
Nov0.470.560.840.9––
Dec0.310.340.650.68––
Year1217.1115.518.41––

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

Similar plants that need less water 16

Rated lower than prairie sage 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 prairie sage, 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 prairie sage in summer?

In July, established prairie sage in loam needs a deep watering about every 5 days in the Central Valley, about every 7 days on the south coast and about every 6 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 prairie sage need per day?

In July in the Central Valley, established prairie sage 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 prairie sage change across California?

Yes. WUCOLS rates prairie sage 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 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 is my prairie sage flopping over?

Its stems flop under the weight of the flowers, especially in rich soil. Cut stems back by half in late spring. Lean soil helps.

Is prairie sage good for pollinators?

Yes, bees and butterflies visit its blue flowers. Native bees nest in the dead, hollow stems. Leave some old stems standing.

When does prairie sage bloom?

It blooms from midsummer into fall. Moderate summer water keeps flowers coming. Deadheading is optional.

Do deer eat prairie sage?

It is resistant to deer browsing. That suits gardens near wild areas. It is surprisingly scarce in nurseries.

How do I propagate prairie sage?

Divide clumps or grow it from seed. It is hard to find in nurseries. Water divisions until they root in.

More plant watering guides

Sources