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

How often to water wisteria in California

In July in the Central Valley, established wisteria in loam needs a deep watering about every 20 days: about 2.2 gallons each time for a plant 2 feet across, about 0.8 gallons a week. Wisteria is a large, long-lived vine with roots that spread deeply and widely as it establishes. Young vines need steady moisture while building that system. Mature growth still needs soil checks, especially as flower buds develop, without keeping the woody crown saturated.

VineRated for 6 of 6 zones

How often to water wisteria, 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 wisteria 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 6 to 8 inches down around an established wisteria signals that it needs a deep soak
  • Leaflets still limp the morning after heat can indicate thirst when the ground is dry
  • Crisp leaflet edges on a young vine after heat warrant a root-ball moisture check
  • Yellow leaves falling over wet ground can indicate poor drainage, while green veins on yellow leaves can reflect iron chlorosis
  • Long leafy shoots with few flowers can accompany excess feeding or irrigation but do not identify the cause alone

How to water it

  • Water established wisteria in a broad ring 2 to 3 feet from the trunk while soaking new vines over and around their root balls
  • Apply water slowly to wet soil 12 to 18 inches down, then wait until it dries 6 to 8 inches down
  • Use drip or a slow hose beneath the vine to keep the woody crown dry
  • Mulch the spreading root area with coarse wood chips, extending beyond the canopy while leaving the trunk clear
  • Use a mound or slope in heavy clay and move emitters outward as the root area expands

Through the seasons

Keep a new wisteria root ball and nearby soil moist through its first summer, expanding coverage as roots spread. Established vines can take deeper, less frequent soakings. Spring bloom can precede leaves on Chinese wisteria, followed by vigorous summer growth. Chinese and Japanese wisterias form next year's flower buds in summer, so keep checking moisture through that period. Reduce irrigation after leaf fall. Coastal and Central Valley rain can supply dormant roots; check both deserts during dry winter gaps. WUCOLS rates wisteria low water in the Central Valley and moderate water in the other five climate zones.

In pots

Wisteria trained as a standard or bonsai has a spreading root system confined to a pot. Check the top couple of inches of mix often in California summer heat and water when dry. Soak until excess leaves the drainage holes, then empty the saucer to keep fine roots out of standing water. A crowded container needs attention to root space as well as moisture. In winter, reduce watering for the leafless vine but keep the mix from drying completely.

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

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.160.780.780.740.78
Feb0.530.260.810.870.930.93
Mar0.870.431.151.31.461.52
Apr1.180.611.41.611.891.95
May1.460.831.611.952.392.45
Jun1.610.991.742.292.852.79
Jul1.611.071.982.513.042.85
Aug1.490.951.862.332.792.6
Sep1.240.721.491.862.142.08
Oct0.870.471.151.331.461.49
Nov0.470.220.840.90.930.96
Dec0.310.140.650.680.650.68
Year126.8415.518.4121.2721.08

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 8

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

BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyFlowering WoodbineLonicera periclymenumlow water, Central Valley1.07 gal/sq ft in JulyFleeceflowerFallopia baldschuanica (Polygonum aubertii)low water, Central Valley1.07 gal/sq ft in JulyCarolina JessamineGelsemium sempervirenslow water, Central Valley1.07 gal/sq ft in JulyCecile Brunner RoseRosa 'Cecile Brunner'low water, Central Valley1.07 gal/sq ft in JulyLady Banks RoseRosa banksiaelow water, Central Valley1.07 gal/sq ft in JulyRoger's Red GrapeVitis 'Roger's Red'low water, Central Valley1.07 gal/sq ft in JulyBlue Dawn Morning GloryIpomoea acuminatalow 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 wisteria, 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 wisteria in summer?

In July, established wisteria in loam needs a deep watering about every 20 days in the Central Valley, about every 11 days on the south coast and about every 9 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 wisteria need per day?

In July in the Central Valley, established wisteria needs about 0.1 gallons a day for a plant 2 feet across and about 0.4 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 wisteria change across California?

Yes. WUCOLS rates wisteria separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, low water in the Central Valley zone, moderate water in the South Coastal zone, moderate 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.

How do I water a new wisteria?

Check the nursery ball itself as well as the ground just beyond it. The ball can dry sooner than nearby soil, but emerging roots also need moisture outside it. Widen coverage during the first season as the vine establishes.

Why does my potted wisteria dry quickly?

Inspect the available root space when the pot repeatedly dries fast. A crowded vine may need root pruning or a larger container. Extra surface sips do not replace a thorough soaking of its root ball.

Does a wisteria tree need different watering?

A trained standard is the same vine carried on a single trunk. Its exposed position can leave roots with less shade than a vine beside a wall. Mulch the root area and judge moisture at that site.

Can you overwater wisteria?

Yes. Water collecting in heavy soil can leave roots without air and lead to branch dieback. Wait for deeper soil to dry and address drainage before repeating irrigation.

Why is my wisteria not blooming?

Age, excess nitrogen, pruning and late frost can all limit flowers. Chinese and Japanese wisterias flower on older wood, while American wisteria flowers on new growth. Check your species before pruning away shoots that could carry flowers.

More plant watering guides

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Sources