WateringTimesWatering plan, $19
Thunbergia grandiflora, WUCOLS IV

How often to water sky flower vine in California

In July on the north-central coast, established sky flower vine in loam needs a deep watering about every 13 days: about 2.2 gallons each time for a plant 2 feet across, about 1.1 gallons a week. Sky flower vine is a vigorous evergreen climber with thick tuberous roots and rope-like stems that can cover a fence or climb into a tree. From midsummer into late fall it opens large, pale blue, flaring flowers with creamy throats. Its tubers give it some tolerance of dry summers, especially near the coast.

VineRated for 4 of 6 zones

How often to water sky flower vine, 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 sky flower vine 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

  • Dry soil 3 inches down around the base of the vine in summer means sky flower vine is ready for water
  • Leaves wilting through the afternoon on the sunny side of the vine can indicate thirst
  • Few flowers in late summer can follow a dry spell or too much shade
  • Yellow leaves and soft stems at the base over soggy soil suggest overwatering

How to water it

  • Water the root zone at the base of the vine with drip or a slow hose
  • Soak about a foot down, then let the top few inches dry
  • Plant where the vine can climb into sun, since it blooms poorly in shade
  • Mulch over the tuberous roots to protect them from frost
  • Give it a sturdy support, since it can climb high and wide

Through the seasons

Water a new sky flower vine regularly through its first summer as the tubers develop. Established vines can be watered regularly or only now and then in coastal gardens. It stays evergreen down to roughly 25 degrees F. A vine frozen to the ground can resprout and climb again within a season. Flowers peak from midsummer to late fall. For the low desert, South Inland, the south coast and the north-central coast, WUCOLS lists a moderate water rating. It considers the vine not suited to the Central Valley or the high desert.

In pots

Sky flower vine can grow in a large container with a trellis, though it is happier in the ground. Water when the top couple of inches of mix are dry, until it drains. In summer heat, check every few days. Empty the saucer. Cut back hard if it outgrows its support. In winter, water lightly and protect the pot from frost. Mulch the top of the pot to shelter the tubers in cold snaps.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Sky Flower Vine for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Sky Flower Vine as not suited to this region for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Sky Flower Vine: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.37–0.780.78–0.78
Feb0.53–0.810.87–0.93
Mar0.87–1.151.3–1.52
Apr1.18–1.41.61–1.95
May1.46–1.611.95–2.45
Jun1.61–1.742.29–2.79
Jul1.61–1.982.51–2.85
Aug1.49–1.862.33–2.6
Sep1.24–1.491.86–2.08
Oct0.87–1.151.33–1.49
Nov0.47–0.840.9–0.96
Dec0.31–0.650.68–0.68
Year12–15.518.41–21.08

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 10

Rated not suited to this region in the Central Valley, like sky flower vine. Plants that drink alike can share one valve and one schedule.

Golden Trumpet VineAllamanda catharticanot rated, Central Valleyno Central Valley ratingPelican FlowerAristolochia giganteanot rated, Central Valleyno Central Valley ratingWax PlantHoya carnosanot rated, Central Valleyno Central Valley ratingFlame VinePyrostegia venustanot rated, Central Valleyno Central Valley ratingCup-of-Gold VineSolandra maximanot rated, Central Valleyno Central Valley ratingMadagascar JasmineStephanotis floribundanot rated, Central Valleyno Central Valley ratingBlack-Eyed Susan VineThunbergia alatanot rated, Central Valleyno Central Valley ratingCoral VineAntigonon leptopusnot rated, Central Valleyno Central Valley ratingQueen's WreathPetrea volubilisnot rated, Central Valleyno Central Valley ratingBeauverd's Widow's-ThrillKalanchoe beauverdiinot rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes sky flower vine, 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 sky flower vine in summer?

In July, established sky flower vine in loam needs a deep watering 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 sky flower vine need per day?

In July on the north-central coast, established sky flower vine needs about 0.2 gallons a day for a plant 2 feet across and about 0.7 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 sky flower vine change across California?

Yes. WUCOLS rates sky flower vine separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, not suited to this region in the Central Valley zone, moderate water in the South Coastal zone, moderate water in the South Inland zone, not suited to this region 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.

Will sky flower vine come back after frost?

Yes, it is evergreen to about 25 degrees F, and if frozen to the ground it can resprout from its roots. It can grow into a large vine again within one season. Mulch the base for extra protection.

Why isn't my sky flower vine blooming?

It does not bloom well in shade. The vine will climb toward the sun, so give it a sunny top to reach. Flowers come from midsummer to late fall.

How big does sky flower vine get?

It can climb high and wide, covering fences or even a good-sized tree. Plan a strong support. Prune to keep it in bounds.

Is sky flower vine invasive?

It has naturalized in tropical regions around the world. In California gardens, watch for spread beyond its support. Cut back runners that wander.

Does sky flower vine need much water?

Its tuberous roots give it some tolerance of dry summers. Near the coast it can get by with occasional water. Inland, regular soaks keep it blooming.

More plant watering guides

Milk BushBoojumOcotilloSilver TreeNew Zealand Christmas TreeTanbark OakPygmy Date PalmBristlecone Pine

Sources