WateringTimesWatering plan, $19
Acacia saligna, WUCOLS IV

How often to water blue leaf wattle in California

In July in the Central Valley, established blue leaf wattle in loam needs a deep watering about every 20 days: about 55 gallons each time under a 10 foot canopy, about 19 gallons a week. Blue leaf wattle is a fast evergreen shrub or small tree from Western Australia, 8 to 20 feet tall. Long, bluish green leaflike phyllodes hang from its weeping branches. Bright yellow puffball flowers cover it in spring, then narrow seedpods follow. It is a low water plant once established, but it suckers, self-sows freely and can spread into wild land.

ShrubTreeRated for 5 of 6 zones

How often to water blue leaf wattle, month by month

Your city
Canopy width
10 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 blue leaf wattle 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 under the branches, 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 canopy width

A tree with its canopy width marked across the widest branches and the circle under it shaded blue

Measure across the branches, from the tips of the outer leaves on one side to the tips on the other. A tape works, or pace it out.

Water the whole circle under the branches, shown in blue. The gallons here cover that circle.

A wider canopy means more gallons each watering, not more waterings. While the tree is young, measure again each spring.

How to tell it needs water

  • Soil dry 18 inches down past the branch tips in a young plant's first summer signals it needs a deep soak
  • Phyllodes drooping and thinning across the crown in a long hot spell can indicate drought stress
  • Yellowing foliage and dieback over soggy soil point to overwatering or poor drainage
  • Suckers and seedlings popping up in irrigated beds show water is helping it spread

How to water it

  • Water a young plant in a ring well outside the trunk with a slow soaker
  • Soak deeply, then let the soil dry well down before watering again
  • Plant in full sun in well-drained soil, away from wildlands and creeks
  • Taper irrigation after the first year or two
  • Cut suckers at the base and pull seedlings while they are small

Through the seasons

Water a young blue leaf wattle deeply through its first summer or two, then let rain carry it. It is evergreen and blooms in spring, when rain usually covers its needs near the coast. It suckers and self-sows, and it has naturalized in coastal and southern California. WUCOLS rates blue leaf wattle low water on the north-central coast, in the Central Valley, on the south coast and in South Inland. The low desert also carries a low water rating. WUCOLS marks it as not suited to the high desert.

In pots

Blue leaf wattle grows too fast for a container beyond its first season, and pots do help keep its seed and suckers contained. Use a gritty, well-drained mix. Water once the mix is dry a few inches down, and let it drain completely. In summer heat, check every few days. Never leave water standing in the saucer. Remove seedpods before they open, and plant it out or replace it within a year.

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
0.280.570.851.10.16JAN0.26FEB0.43MAR0.61APR0.83MAY0.99JUN1.07JUL0.95AUG0.72SEP0.47OCT0.22NOV0.14DEC0.280.570.851.10.16JFM0.61AMJ1.07JAS0.47OND
Gallons per square foot per month, Central Valley. Peak 1.07 in Jul, 6.84 a year.

Monthly water need by climate zone

Blue Leaf Wattle: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.160.310.31–0.31
Feb0.210.260.320.35–0.37
Mar0.350.430.460.52–0.61
Apr0.470.610.560.64–0.78
May0.580.830.640.78–0.98
Jun0.640.990.690.92–1.12
Jul0.641.070.791–1.14
Aug0.60.950.740.93–1.04
Sep0.50.720.60.74–0.83
Oct0.350.470.460.53–0.6
Nov0.190.220.330.36–0.38
Dec0.120.140.260.27–0.27
Year4.86.846.27.37–8.43

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 blue leaf wattle. 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 JulyFig TreesFicus carica 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 JulyPomegranate TreesPunica granatumlow water, Central Valley1.07 gal/sq ft in JulyEucalyptusEucalyptus polyanthemoslow water, Central Valley1.07 gal/sq ft in JulyPine TreesPinus canariensislow 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 July
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes blue leaf wattle, 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 blue leaf wattle in summer?

In July, established blue leaf wattle 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 blue leaf wattle need per day?

In July in the Central Valley, established blue leaf wattle needs about 2.7 gallons a day under a 10 foot canopy and about 11 gallons a day under a 20 foot canopy. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Does watering for blue leaf wattle change across California?

Yes. WUCOLS rates blue leaf wattle 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, not suited to this region in the High and Intermediate Desert zone, low 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 blue leaf wattle invasive?

It has escaped gardens along the coast and in southern California, and it is rated a high risk for becoming invasive. It spreads by seed and suckers. Avoid planting it near wildland.

Why is my wattle sending up shoots?

It suckers from the roots and can form thickets. Cut suckers at the base.

When does blue leaf wattle bloom?

Bright yellow, round flower clusters cover it in spring. Long, narrow seedpods follow. Remove pods to cut down on seedlings.

Does fire help wattle spread?

Yes, fire encourages regrowth and seed germination. That is one reason it spreads in wild areas. Keep it out of fire-prone open space.

How fast does blue leaf wattle grow?

It grows fast, often reaching 8 to 20 feet tall and wide. Plan for its full size. Its dense canopy shades out plants beneath.

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Sources