WateringTimesWatering plan, $19
Vitis labrusca ssp. & cvs., WUCOLS IV

How often to water American grape in California

In July in the Central Valley, established American grape 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. American grape is the North American fox grape and the parent of slip-skin table grapes such as Concord and Niagara. It is a vigorous deciduous vine with good resistance to pests and disease, and it is very cold hardy. It ripens best with moderate summer heat, deep but infrequent watering, and soil that is moist without staying wet.

VineRated for 6 of 6 zones

How often to water American grape, 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 American grape 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 inches down along the drip line of a vine in early summer signals that it needs a deep soak
  • Shoot tips that stop growing and leaves wilting at midday before fruit set can point to a dry root zone
  • Rank, leafy growth with long canes and few clusters often follows too much water or fertilizer
  • Yellow leaf spots that turn white and powdery point to powdery mildew, which shade and overwatering encourage
  • Leaves yellowing and dropping in fall mark normal dormancy, not drought

How to water it

  • Run drip lines along the trellis, on a zone separate from lawn and landscape plants
  • Water deeply but infrequently, wetting the soil about 2 feet down and letting the top dry before the next soak
  • Plant in full sun, seven to eight hours a day, with rows running north to south
  • Ease back slightly on water once the fruit sets, without letting the vine wilt
  • Thin crowded shoots and leaves in summer so air and sun reach the clusters

Through the seasons

A new American grape needs steady deep watering in its first summer while roots grow, and a full crop takes four or five years. Established vines want deep, spaced soakings from bud break through harvest, with slightly less water once fruit sets. Leaves drop in fall, and winter rain covers the dormant vine on the coast and in the Central Valley. Desert vines need a soil check in dry winters. It tolerates cold down to about 20 below zero. WUCOLS rates American grape moderate water on the north-central coast, in the Central Valley, on the south coast and in South Inland. The same moderate water rating holds in the high desert and the low desert.

In pots

American grape can grow in a large, deep container on a sturdy trellis. Check the mix 2 to 3 inches down every few days in summer, and water until it drains through, then empty the saucer. A vine in a pot dries much faster than one in the ground, so check it more often during heat waves. After the leaves drop in fall, water only enough to keep the mix from drying out until buds swell.

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

American Grape: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.780.740.78
Feb0.530.650.810.870.930.93
Mar0.871.091.151.31.461.52
Apr1.181.521.41.611.891.95
May1.462.081.611.952.392.45
Jun1.612.481.742.292.852.79
Jul1.612.671.982.513.042.85
Aug1.492.391.862.332.792.6
Sep1.241.81.491.862.142.08
Oct0.871.181.151.331.461.49
Nov0.470.560.840.90.930.96
Dec0.310.340.650.680.650.68
Year1217.1115.518.4121.2721.08

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 American grape. 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 JulyEvergreen ClematisClematis armandiimoderate water, Central Valley2.67 gal/sq ft in JulyWinter CreeperEuonymus fortunei radicansmoderate water, Central Valley2.67 gal/sq ft in JulyArabian JasmineJasminum sambacmoderate water, Central Valley2.67 gal/sq ft in JulyHyacinth BeanLablab purpureus (Dolichos lablab)moderate water, Central Valley2.67 gal/sq ft in JulyTrumpet HoneysuckleLonicera sempervirensmoderate water, Central Valley2.67 gal/sq ft in JulyPink Trumpet VinePodranea ricasolianamoderate water, Central Valley2.67 gal/sq ft in JulyPotato VineSolanum laxum (jasminoides)moderate water, Central Valley2.67 gal/sq ft in JulyItalian ClematisClematis viticellamoderate water, Central Valley2.67 gal/sq ft in JulyHopsHumulus lupulusmoderate water, Central Valley2.67 gal/sq ft in JulyBoston IvyParthenocissus tricuspidatamoderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 9

Rated lower than American grape 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 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 American grape, 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 American grape in summer?

In July, established American grape 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 American grape need per day?

In July in the Central Valley, established American grape 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 American grape change across California?

Yes. WUCOLS rates American grape 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, 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.

What is a slip-skin grape?

American grapes such as Concord have skins that slip easily off the pulp. That sets them apart from European table grapes, which have thin, tight skins. Both types want the same deep, infrequent watering.

Why is my grape vine all leaves and no fruit?

Too much water or fertilizer pushes leafy cane growth and fewer clusters. Young vines also need four or five years to bear a full crop. Water deeply but less often, and skip extra nitrogen.

Does American grape get powdery mildew?

American types resist pests and disease fairly well, but mildew can still appear when temperatures sit between 70 and 85 degrees. Avoid overwatering and heavy feeding, and thin leaves for air and light.

Does American grape grow well where summers are mild?

Yes. It has only moderate summer heat requirements, so it suits mild climates as well as warmer ones. In cool coastal gardens, early ripening varieties do best.

When should I plant American grape?

Plant bare-root vines in February, trimming broken roots and setting them no deeper than they grew in the nursery. Cut the new vine back to its strongest cane with two buds. Water to settle the soil, then keep it moist as growth starts.

More plant watering guides

ButtonbushKatsura TreeEastern RedbudChinese RedbudJudas TreeNight JessamineChilean JessamineEvergreen Clematis

Sources