WateringTimesWatering plan, $19
Parthenocissus tricuspidata, WUCOLS IV

How often to water Boston ivy in California

In July in the Central Valley, established Boston ivy in loam needs a deep watering about every 8 days: about 2.2 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Boston ivy is a fast-growing vine from Japan and eastern China that climbs 30 to 50 feet by tendrils tipped with adhesive pads. Its large, glossy, three-lobed leaves turn bright red to burgundy in fall, then drop to reveal small dark berries that birds eat. It grows in sun or shade in most soils and can also spread as a groundcover.

Ground coverVineRated for 6 of 6 zones

How often to water Boston ivy, 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 Boston ivy 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

  • When the soil where the stems enter the ground is dry an inch or two deep in summer, give the vine a long drink
  • Leaves wilting on a hot, sunny wall in midsummer show the roots need water
  • Yellowing leaves over soggy ground point to poor drainage rather than thirst
  • Powdery white patches or spots on the leaves point to mildew or leaf spot, not to water
  • Red fall color and leaf drop are its normal seasonal change, not drought

How to water it

  • Aim a drip emitter or slow hose at the root zone until moisture reaches roughly 8 inches
  • Allow the upper soil to dry out before each watering on an established vine
  • Train it onto masonry or a sturdy structure, never onto wood or shingle siding, gutters or trees
  • Trim it back regularly to keep it in bounds and away from windows and wiring
  • Widen the watered area as the vine spreads along a wall base or slope

Through the seasons

Water a new vine regularly through its first summer while it roots and begins to climb. Leaves emerge in late spring, stay green all summer and turn red to burgundy before dropping in fall. Small flowers in late spring hide among the leaves, and the berries show after leaf drop. Winter rain covers the bare vine on the coast and in the Central Valley. WUCOLS rates Boston ivy low water on the north-central coast. It rates moderate water in the Central Valley, on the south coast and in South Inland. In both desert zones, the high desert and the low desert, it rates moderate water as well.

In pots

Boston ivy can grow in a large container placed against a masonry wall or sturdy trellis. Use a well-drained mix and a pot with drainage holes. On hot summer days, press a finger into the mix every second day and water as soon as the upper inch has dried. Let water drain through, then empty the saucer. Trim runaway shoots before they reach gutters, and water only lightly after the leaves fall.

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
0.761.52.33.00.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.761.52.33.00.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Boston Ivy: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.150.40.780.780.740.78
Feb0.210.650.810.870.930.93
Mar0.351.091.151.31.461.52
Apr0.471.521.41.611.891.95
May0.582.081.611.952.392.45
Jun0.642.481.742.292.852.79
Jul0.642.671.982.513.042.85
Aug0.62.391.862.332.792.6
Sep0.51.81.491.862.142.08
Oct0.351.181.151.331.461.49
Nov0.190.560.840.90.930.96
Dec0.120.340.650.680.650.68
Year4.817.1115.518.4121.2721.08

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 16

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

JasmineJasminum polyanthummoderate water, Central Valley2.67 gal/sq ft in JulyStar JasmineTrachelospermum jasminoides and cvs.moderate water, Central Valley2.67 gal/sq ft in JulyHoneysuckleLonicera japonicamoderate water, Central Valley2.67 gal/sq ft in JulyIvyHedera helixmoderate water, Central Valley2.67 gal/sq ft in JulyGrapevinesVitis vinifera ssp. & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyClematisClematis & ssp., hybrids & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyStrawberriesFragaria spp. & cvs. (CA native and non-natives species)moderate water, Central Valley2.67 gal/sq ft in JulyCarpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in JulyGreen Supreme ManzanitaArctostaphylos uva-ursi 'Green Supreme'moderate water, Central Valley2.67 gal/sq ft in JulyMassachusetts ManzanitaArctostaphylos uva-ursi 'Massachusetts'moderate water, Central Valley2.67 gal/sq ft in JulySerbian BellflowerCampanula poscharskyanamoderate water, Central Valley2.67 gal/sq ft in JulyEvergreen ClematisClematis armandiimoderate water, Central Valley2.67 gal/sq ft in JulyBunchberryCornus canadensismoderate water, Central Valley2.67 gal/sq ft in JulyKenilworth IvyCymbalaria muralismoderate water, Central Valley2.67 gal/sq ft in JulyWinter CreeperEuonymus fortunei radicansmoderate water, Central Valley2.67 gal/sq ft in JulyCranesbillGeranium spp.moderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

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

BougainvilleaBougainvillea & spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyWisteriaWisteria spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyLantanaLantana camara ssp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyJunipersJuniperus spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyYarrowAchillea millefolium (non-native hybrids)low water, Central Valley1.07 gal/sq ft in JulySagebrushArtemisia spp. (shrubby)low water, Central Valley1.07 gal/sq ft in JulyFlowering WoodbineLonicera periclymenumlow water, Central Valley1.07 gal/sq ft in JulyCalifornia Native YarrowAchillea millefolium (CA native cultivars)low water, Central Valley1.07 gal/sq ft in JulyWoolly YarrowAchillea tomentosalow water, Central Valley1.07 gal/sq ft in JulyGround Morning GloryConvolvulus mauritanicuslow water, Central Valley1.07 gal/sq ft in JulyRock CotoneasterCotoneaster horizontalislow 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 JulySouth African GeraniumPelargonium sidoideslow water, Central Valley1.07 gal/sq ft in JulyLippia GroundcoverPhyla nodiflora (Lippia nodiflora) cvs.low water, Central Valley1.07 gal/sq ft in JulyCecile Brunner RoseRosa 'Cecile Brunner'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 Boston ivy, 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 Boston ivy in summer?

In July, established Boston ivy in loam needs a deep watering about every 8 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 Boston ivy need per day?

In July in the Central Valley, established Boston ivy 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 Boston ivy change across California?

Yes. WUCOLS rates Boston ivy separately for each of the six California climate zones: low 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, 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 Boston ivy the same as English ivy?

No. Boston ivy is a deciduous vine in the grape family and is unrelated to evergreen English ivy. It drops its leaves after a show of fall color.

Will Boston ivy damage my house?

It can. Its holdfasts are hard to remove, can creep under shingles, ruin paint and grab gutters, shutters and wiring. To remove it, cut the vine at the base first so the pads dry out and let go.

Can Boston ivy grow in shade?

Yes. It grows in full sun to shade and in most soils. Fall color is a strong point wherever it grows.

Can Boston ivy grow up trees?

Do not let it. It can overgrow and outcompete many trees. Keep it on walls, fences or the ground.

Can you overwater Boston ivy?

Yes. It needs soil that drains, and ground that stays soggy yellows the leaves. Let the top couple of inches dry between waterings.

More plant watering guides

Roman ChamomileItalian ClematisNew Zealand Cabbage TreeAmerican PersimmonHairy Canary CloverCockspur Coral TreeMartin's SpurgeSheep Fescue

Sources