WateringTimesWatering plan, $19
Phlomis fruticosa, WUCOLS IV

How often to water Jerusalem sage in California

In July in the Central Valley, established Jerusalem sage in loam needs a deep watering about every 20 days: about 8.8 gallons each time for a plant 4 feet across, about 3.0 gallons a week. Jerusalem sage is a mounding evergreen shrub from Mediterranean hillsides, 2 to 5 feet tall and wider. Its wrinkled, woolly gray-green leaves are white beneath. Whorls of yellow, hooded flowers stack in tiers up the stems from late spring into summer and draw bees and hummingbirds. It is drought tolerant and wants fast drainage and good air circulation.

ShrubRated for 6 of 6 zones

How often to water Jerusalem sage, 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 Jerusalem 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 1.5 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 4 inches down beside the shrub in a first summer signals a young Jerusalem sage needs a soak
  • Woolly leaves curling and drooping in heat can indicate a long dry spell
  • Lower leaves browning and dropping after a dry stretch in summer can follow drought stress
  • Stems blackening and collapsing from the base in wet soil point to rot from overwatering

How to water it

  • Water at the base with drip or a slow hose, keeping the woolly leaves dry
  • Soak several inches down, then let the soil dry well before the next soak
  • Plant in full sun to part shade in fast-draining soil with good air flow
  • Use gravel or a thin mulch kept back from the stems
  • Taper to occasional deep soaks once it is established

Through the seasons

Water a new Jerusalem sage regularly through its first summer while roots spread. Established shrubs are drought tolerant and need only occasional deep soaks. It stays evergreen in mild climates and flowers from late spring into summer. Winter rain usually covers the cool months outside the deserts. WUCOLS rates Jerusalem sage low water on the north-central coast, in the Central Valley, on the south coast and in South Inland. In the high desert and the low desert it carries a moderate water rating.

In pots

Jerusalem sage grows well in a large pot of gritty, fast-draining mix in full sun. Water once the mix is dry a couple of inches down, letting it drain completely. In summer heat, a pot may need water every few days. Never leave it in a full saucer. Cut back spent flower stems after bloom. In winter, water rarely and keep the pot where rain drains away freely.

1 Your climate zone six WUCOLS zones, each from its own reference city
1.07gal per sq ft in JulyLow water use in the Central Valley zone
A year
6.84 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
0.761.52.33.00.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.761.52.33.00.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.160.310.310.740.78
Feb0.210.260.320.350.930.93
Mar0.350.430.460.521.461.52
Apr0.470.610.560.641.891.95
May0.580.830.640.782.392.45
Jun0.640.990.690.922.852.79
Jul0.641.070.7913.042.85
Aug0.60.950.740.932.792.6
Sep0.50.720.60.742.142.08
Oct0.350.470.460.531.461.49
Nov0.190.220.330.360.930.96
Dec0.120.140.260.270.650.68
Year4.86.846.27.3721.2721.08

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

LavenderLavandula spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRosemaryRosmarinus officinalislow water, Central Valley1.07 gal/sq ft in JulyBougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyOlive TreesOlea europaea ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyCrape MyrtleLagerstroemia spp., hybrids & cvs.low water, Central Valley1.07 gal/sq ft in JulyLantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in JulyAloeAloe spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyJunipersJuniperus spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRussian SagePerovskia spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulySagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in JulyWild PrivetLigustrum vulgarelow water, Central Valley1.07 gal/sq ft in JulyCoralberrySymphoricarpos orbiculatus (SHADE)low water, Central Valley1.07 gal/sq ft in JulySydney Golden WattleAcacia longifolialow water, Central Valley1.07 gal/sq ft in JulyBlue Leaf WattleAcacia salignalow water, Central Valley1.07 gal/sq ft in July
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes Jerusalem 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 Jerusalem sage in summer?

In July, established Jerusalem sage in loam needs a deep watering about every 20 days in the Central Valley, about every 27 days on the south coast and about every 22 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 Jerusalem sage need per day?

In July in the Central Valley, established Jerusalem sage needs about 0.4 gallons a day for a plant 4 feet across and about 1.7 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 Jerusalem sage change across California?

Yes. WUCOLS rates Jerusalem sage separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, low water in the South Coastal zone, low water in the South Inland zone, moderate water in the High and Intermediate Desert zone, moderate water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Is Jerusalem sage a true sage?

No, it is a Phlomis, though it is in the mint family like sages. Its leaves feel woolly, like lamb's ear. The flowers are yellow and hooded.

Why is my Jerusalem sage leggy?

Shade makes it leggy and sparse. Move it to full sun or partial shade at most. Cut it back after bloom to keep it dense.

Do deer eat Jerusalem sage?

It is deer and rabbit resistant. Damage is more likely from wet soil. Check drainage first.

Should I deadhead Jerusalem sage?

You can cut spent stems after bloom to tidy the plant. Watering does not change either way. Look for new flowers on fresh stems.

Does Jerusalem sage attract hummingbirds?

Yes, its nectar draws bees, butterflies and hummingbirds. Bloom runs from late spring into summer. Water deeply but rarely during bloom.

More plant watering guides

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Sources