WateringTimesWatering plan, $19
Lupinus polyphyllus, WUCOLS IV

How often to water bigleaf lupine in California

In July in the Central Valley, established bigleaf lupine in loam needs a deep watering about every 5 days: about 1.5 gallons each time for a plant 2 feet across, about 1.9 gallons a week. Bigleaf lupine is a tall perennial wildflower of western North America, found in California around wet seeps and mountain meadows. Large, long-stalked leaves split into slender leaflets form a mound, topped in summer by spikes of pea-like blue, purple or reddish flowers. Plants reach about 5 feet and need full sun and steady moisture while they grow.

PerennialCalifornia nativeRated for 2 of 6 zones

How often to water bigleaf lupine, 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 bigleaf lupine 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 foot 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 an inch or two down around the clump in summer means this moisture-loving lupine needs water
  • Leaves drooping by midday in hot weather show the roots have run short of water
  • Plants collapsing in soil that stays waterlogged point to poor drainage rather than thirst
  • Ragged holes in new spring shoots come from slugs and snails, not from a watering problem
  • Clusters of aphids on the stems or a white powder on the leaves point to lupin aphid or powdery mildew

How to water it

  • Water at the base of the clump with drip or a soaker
  • Keep the root zone evenly moist through growth and bloom, soaking it about 8 inches deep
  • Plant in full sun in light, slightly acid soil that drains, since shade cuts flowering
  • Set plants where they can stay, because lupines resent root disturbance
  • Cut spent spikes for a second flush of flowers, and stake tall stems if they lean

Through the seasons

Water new plants regularly through their first summer, especially in hot, dry spells. Growth starts in spring, flowers open in summer, and the foliage dies back for winter. In the wild it grows in wet seeps near snowfields, so it does not expect a long dry season. WUCOLS rates bigleaf lupine high water on the north-central coast, and moderate water in the Central Valley. WUCOLS marks it as not suited to South Inland. WUCOLS has not evaluated it for the south coast, the high desert or the low desert.

In pots

Shorter lupines suit pots best, but bigleaf lupine can grow in a deep container where garden soil stays waterlogged. Use a loam-based mix with added grit and a pot with drainage holes. Through the growing season, check the mix every day or two in summer heat and water when the top inch dries. Let excess water drain, then empty the saucer. Repot before it becomes pot-bound, since crowded roots cut flowering. After it dies back for winter, water only lightly.

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
0.671.32.02.70.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC0.671.32.02.70.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Bigleaf Lupine: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.60.4––––
Feb0.840.65––––
Mar1.391.09––––
Apr1.881.52––––
May2.332.08––––
Jun2.582.48––––
Jul2.582.67––––
Aug2.382.39––––
Sep1.981.8––––
Oct1.391.18––––
Nov0.740.56––––
Dec0.50.34––––
Year19.217.11––––

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 bigleaf lupine. Plants that drink alike can share one valve and one schedule.

DahliasDahlia spp.moderate water, Central Valley2.67 gal/sq ft in JulyFernsNephrolepis cordifolia (SHADE IN DESERT)moderate water, Central Valley2.67 gal/sq ft in JulyDayliliesHemerocallis spp. & cvs.moderate water, Central Valley2.67 gal/sq ft in JulyBegoniasBegonia & ssp. & cvs. (shade in the desert)moderate water, Central Valley2.67 gal/sq ft in JulyCalla LiliesZantedeschia aethiopica SHADE IN DESERTmoderate water, Central Valley2.67 gal/sq ft in JulySageSalvia officinalis and cvs.moderate water, Central Valley2.67 gal/sq ft in JulyBicolor MonkshoodAconitum cammarummoderate water, Central Valley2.67 gal/sq ft in JulyGarden MonkshoodAconitum napellusmoderate water, Central Valley2.67 gal/sq ft in JulyCarpet BugleAjuga reptans (shade)moderate water, Central Valley2.67 gal/sq ft in JulySnowdrop WindflowerAnemone sylvestrismoderate water, Central Valley2.67 gal/sq ft in JulyMountain SandwortArenaria montanamoderate water, Central Valley2.67 gal/sq ft in JulySwamp MilkweedAsclepias incarnatamoderate water, Central Valley2.67 gal/sq ft in JulyOrange MilkweedAsclepias tuberosamoderate water, Central Valley2.67 gal/sq ft in JulyGreater MasterwortAstrantia majormoderate water, Central Valley2.67 gal/sq ft in JulyHardy BegoniaBegonia grandismoderate water, Central Valley2.67 gal/sq ft in JulyWax BegoniaBegonia semperflorensmoderate water, Central Valley2.67 gal/sq ft in July

Similar plants that need less water 16

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

AgapanthusAgapanthus orientalislow water, Central Valley1.07 gal/sq ft in JulyGeraniumsPelargonium x hortorum and cvs.low water, Central Valley1.07 gal/sq ft in JulySalviaSalvia greggii ssp., cvs. & hybridslow water, Central Valley1.07 gal/sq ft in JulyIrisesIris germanicalow water, Central Valley1.07 gal/sq ft in JulySucculentsEcheveria spp. & cvs.low water, Central Valley1.07 gal/sq ft in JulyRussian SagePerovskia 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 JulyMountain AlyssumAlyssum montanumlow water, Central Valley1.07 gal/sq ft in JulySilver SageSalvia argentealow water, Central Valley1.07 gal/sq ft in JulyPurple MulleinVerbascum phoeniceumlow water, Central Valley1.07 gal/sq ft in JulySilvery YarrowAchillea clavennaelow water, Central Valley1.07 gal/sq ft in JulyFern Leaf YarrowAchillea filipendulinalow 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 JulyPerennial HollyhockAlcea rosea cvs.low water, Central Valley1.07 gal/sq ft in JulyMountain Lady's MantleAlchemilla alpinalow 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 bigleaf lupine, 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 much water does bigleaf lupine need per day?

In July in the Central Valley, established bigleaf lupine 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 bigleaf lupine change across California?

Yes. WUCOLS rates bigleaf lupine separately for each of the six California climate zones: high water in the North-Central Coastal zone, moderate water in the Central Valley zone, not evaluated in the South Coastal zone, not suited to this region in the South Inland zone, not evaluated in the High and Intermediate Desert zone, not evaluated in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Is bigleaf lupine poisonous?

Yes. It is harmful if eaten and toxic to dogs, cats and other pets, and the seeds can cause severe discomfort if swallowed. Wear gloves when handling seeds and cuttings.

Why is my lupine not flowering?

Too much shade and dividing clumps too often both cut flowering. Lupines also prefer soil fairly low in nutrients. Move it into full sun and leave the clump undisturbed.

Can I move or divide bigleaf lupine?

It dislikes root disturbance, so transplanting often fails. Raise new plants from basal stem cuttings in mid to late spring, or from seed sown in early to mid spring.

How do I get lupines to bloom again?

Cut off the faded flower spikes before they set seed. That encourages a second flush of flowers later in summer. Keep the soil evenly moist while the new spikes form.

Can you overwater bigleaf lupine?

Yes. It likes moisture, yet ground that stays waterlogged is a poor fit, and seedlings rot in soil that is too damp. In heavy, wet soil, grow it in a raised bed or a deep container.

Is bigleaf lupine native to California?

Yes. Its range covers western North America, and a California form grows in red fir forest and mountain meadows. It can tolerate seasonal flooding in those settings.

More plant watering guides

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Sources