WateringTimesWatering plan, $19
Lobelia cardinalis hybrids and cvs. (CA native and non-native spp.), WUCOLS IV

How often to water cardinal flower in California

In July in the Central Valley, established cardinal flower in loam needs a deep watering about every 3 days: about 1.5 gallons each time for a plant 2 feet across, about 3.0 gallons a week. Cardinal flower is a perennial in the bellflower family that grows 4 to 5 feet tall in moist places, named for its brilliant red flowers. Spikes open from the bottom up from late summer into mid fall and draw hummingbirds and butterflies. Many hybrids and cultivars exist. It needs soil that stays moist at all times and can handle a short flood.

PerennialCalifornia nativeRated for 4 of 6 zones

How often to water cardinal flower, 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 cardinal flower 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 that has lost its dampness at the surface around cardinal flower means it needs water right away
  • Lower leaves wilting and browning in summer point to dry soil
  • Flower spikes stopping early in hot, dry weather can follow a dry root zone
  • Leaves scorching in hot afternoon sun point to too much exposure

How to water it

  • Keep the soil constantly moist to wet
  • Plant in rich soil in part shade to full sun
  • Give it afternoon shade in hot inland gardens
  • Mulch the roots to hold moisture
  • Divide rosettes in spring to keep plants vigorous

Through the seasons

Keep new plants consistently moist from the start. Established plants still need soil that never dries out, along with mulch and afternoon shade in hot climates. Flowers open from the bottom of each spike upward from late summer into mid fall. After bloom, plants rest as low rosettes. WUCOLS rates cardinal flower high water on the north-central coast, in the Central Valley, on the south coast and in South Inland. The high desert and the low desert have no WUCOLS evaluation for it.

In pots

Cardinal flower grows well in a pot set at a pond edge or in a deep tray of water, where its red spikes draw hummingbirds close. Use a rich, moisture-holding mix. Water whenever the surface starts to dry, which may be daily in summer, so the mix stays evenly moist. In hot areas, keep the pot in afternoon shade. In winter, keep the mix damp while the plant rests as a low rosette.

1 Your climate zone six WUCOLS zones, each from its own reference city
4.27gal per sq ft in JulyHigh water use in the Central Valley zone
A year
27.38 gal per sq ft
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses
1.12.13.24.30.64JAN1.04FEB1.74MAR2.43APR3.32MAY3.97JUN4.27JUL3.82AUG2.88SEP1.88OCT0.89NOV0.55DEC1.12.13.24.30.64JFM2.43AMJ4.27JAS1.88OND
Gallons per square foot per month, Central Valley. Peak 4.27 in Jul, 27.38 a year.

Monthly water need by climate zone

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

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.60.641.241.24––
Feb0.841.041.291.39––
Mar1.391.741.842.08––
Apr1.882.432.232.58––
May2.333.322.583.12––
Jun2.583.972.783.67––
Jul2.584.273.174.02––
Aug2.383.822.983.72––
Sep1.982.882.382.98––
Oct1.391.881.842.13––
Nov0.740.891.341.44––
Dec0.50.551.041.09––
Year19.227.3824.829.46––

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 high water in the Central Valley, like cardinal flower. Plants that drink alike can share one valve and one schedule.

Japanese Sweet FlagAcorus gramineushigh water, Central Valley4.27 gal/sq ft in JulyRed GingerAlpinia purpuratahigh water, Central Valley4.27 gal/sq ft in JulyShell GingerAlpinia zerumbethigh water, Central Valley4.27 gal/sq ft in JulySiberian BuglossBrunnera macrophyllahigh water, Central Valley4.27 gal/sq ft in JulyMarsh MarigoldCaltha palustrishigh water, Central Valley4.27 gal/sq ft in JulyUmbrella Sedge and PapyrusCyperus spp. (CA native and non-native species)high water, Central Valley4.27 gal/sq ft in JulyUmbrella PlantDarmera peltata (Peltiphyllum)high water, Central Valley4.27 gal/sq ft in JulyFoxgloveDigitalis purpurea cvshigh water, Central Valley4.27 gal/sq ft in JulyLeopard PlantFarfugium japonicum cvs. (Ligularia tussilaginea cvs.)high water, Central Valley4.27 gal/sq ft in JulyTransvaal DaisyGerbera jamesonii & hybridshigh water, Central Valley4.27 gal/sq ft in JulyGiant GunneraGunnera manicatahigh water, Central Valley4.27 gal/sq ft in JulyWhite Ginger LilyHedychium coronariumhigh water, Central Valley4.27 gal/sq ft in JulyJapanese IrisIris ensatahigh water, Central Valley4.27 gal/sq ft in JulyRushJuncus aquatic spp. (native and non-native spp.)high water, Central Valley4.27 gal/sq ft in JulyBananaMusa spp. (shade in low desert)high water, Central Valley4.27 gal/sq ft in JulySensitive FernOnoclea sensibilishigh water, Central Valley4.27 gal/sq ft in July

Similar plants that need less water 16

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

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
Minutes for your sprinklers

Turn this into minutes on your water days

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

In July, established cardinal flower in loam needs a deep watering about every 3 days in the Central Valley, about every 5 days on the south coast and about every 4 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 cardinal flower need per day?

In July in the Central Valley, established cardinal flower needs about 0.4 gallons a day for a plant 2 feet across and about 1.7 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 cardinal flower change across California?

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

Does cardinal flower need wet soil?

Yes, its soil should never dry out, and it tolerates brief flooding. It suits stream banks, ponds and rain gardens. Mulch helps.

Does cardinal flower attract hummingbirds?

Yes, its brilliant red flowers attract hummingbirds and butterflies. Bloom runs from late summer into mid fall. Plant it where you can watch.

Is cardinal flower poisonous?

It has medium severity poison characteristics. Keep children and pets from eating it. Wear gloves when dividing.

Can cardinal flower grow in sun?

It grows in part shade to full sun, but afternoon shade helps in hot climates. Sun means more water. Keep the soil moist.

How do I propagate cardinal flower?

Grow it from seed, or separate rosettes from the parent in spring. Keep divisions moist. Replant at the same depth.

More plant watering guides

Variegated Sweet FlagChameleon HouttuyniaBaby's TearsBellflowerVine MapleHydrangeaBlueberriesBig Leaf Maple

Sources