WateringTimesWatering plan, $19
Hibiscus moscheutos & cvs., WUCOLS IV

How often to water mallow rose in California

In July in the Central Valley, established mallow rose 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. Mallow rose is a tall, woody-based perennial native to wetlands and creek edges of the southeastern United States. From midsummer to early fall it opens huge hollyhock-like flowers up to 8 inches across. They come in white, pink, red or burgundy, each with a dark eye. It wants full sun and wet to constantly moist soil, and it tolerates heat and humidity.

PerennialRated for 5 of 6 zones

How often to water mallow rose, 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 mallow rose 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 beside the clump in summer signals mallow rose needs water
  • Large leaves wilting by midday and staying limp can indicate thirst
  • Flower buds dropping before they open can follow a dry root zone
  • Fewer flowers and more leaf spotting in shade point to too little sun rather than water

How to water it

  • Keep the root zone moist with drip or a soaker under the leaves
  • Water before the top inch dries, since it prefers constantly moist soil
  • Plant in full sun in loamy soil rich in organic matter, sheltered from wind
  • Space plants for good air circulation
  • Deadhead spent flowers to improve the plant's appearance

Through the seasons

Keep a new mallow rose evenly moist from the start. Established clumps still want wet to constantly moist soil through the growing season, especially during midsummer bloom. Top growth dies back in winter, and new shoots rise from the woody base. WUCOLS rates mallow rose moderate water on the north-central coast, in the Central Valley and on the south coast. The high desert shares that moderate water rating. In South Inland it carries a high water rating. WUCOLS has not evaluated it for the low desert.

In pots

Mallow rose can grow in a large container that holds plenty of moist, rich mix. Water whenever the top inch begins to dry, which can mean daily in summer sun. A saucer kept partly filled helps in hot weather. Deadhead spent flowers to keep it tidy. After frost, cut the stems back and keep the mix lightly moist until new shoots appear. Shelter the pot from strong wind.

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
1.02.03.04.00.4JAN0.65FEB1.09MAR1.52APR2.08MAY2.48JUN2.67JUL2.39AUG1.8SEP1.18OCT0.56NOV0.34DEC1.02.03.04.00.4JFM1.52AMJ2.67JAS1.18OND
Gallons per square foot per month, Central Valley. Peak 2.67 in Jul, 17.11 a year.

Monthly water need by climate zone

Mallow Rose: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.781.240.74–
Feb0.530.650.811.390.93–
Mar0.871.091.152.081.46–
Apr1.181.521.42.581.89–
May1.462.081.613.122.39–
Jun1.612.481.743.672.85–
Jul1.612.671.984.023.04–
Aug1.492.391.863.722.79–
Sep1.241.81.492.982.14–
Oct0.871.181.152.131.46–
Nov0.470.560.841.440.93–
Dec0.310.340.651.090.65–
Year1217.1115.529.4621.27–

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 mallow rose. 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 mallow rose 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 mallow rose, 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 mallow rose in summer?

In July, established mallow rose in loam needs a deep watering about every 5 days in the Central Valley, about every 7 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 mallow rose need per day?

In July in the Central Valley, established mallow rose 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 mallow rose change across California?

Yes. WUCOLS rates mallow rose 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, high water in the South Inland zone, moderate water 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.

How big are mallow rose flowers?

The flowers can reach 8 inches across, with a contrasting dark center. Each flower lasts only a short time, but blooming continues for weeks. Deadheading keeps the plant tidy.

Does mallow rose need full sun?

Full sun gives the most flowers and better disease resistance. It tolerates partial sun. Shelter it from strong wind.

Is mallow rose native?

It is native to wetlands and creek edges in the southeastern United States, not California. It suits wet spots in California gardens. Give it steady water.

Can mallow rose grow in wet soil?

Yes, it comes from swampy ground and tolerates wet soil well. It does well near ponds and in rain gardens. Do not let it dry out.

Should I pinch mallow rose?

Pinching the growing tips encourages a bushier plant. Water well afterward.

More plant watering guides

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Sources