WateringTimesWatering plan, $19
Solidago spp. & hybrids, WUCOLS IV

How often to water goldenrod in California

In July in the Central Valley, established goldenrod 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. Goldenrods are herbaceous perennials in the daisy family, mostly native to North America. Tall stems carry dense plumes of tiny yellow flowers from late summer into fall, busy with bees and butterflies. Many spread by underground rhizomes and seed. They grow easily in full sun and well-drained soil, and want moderate summer water rather than a soggy bed.

PerennialRated for 4 of 6 zones

How often to water goldenrod, 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 goldenrod 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 several inches down in the clump during summer means it is time for a deep watering
  • Drooping stems and wilting lower leaves on a hot afternoon, with the soil dry, mean the clump is thirsty
  • Some goldenrods shed their basal leaves before flowering, so lower leaf loss in late summer is not always a water problem
  • White powdery coating or orange rust spots on the leaves point to fungal disease, not a lack of water
  • Yellowing, collapsing stems in soil that stays wet point to root rot from poor drainage

How to water it

  • Water at the base of the clump with drip or a soaker hose rather than wetting the foliage
  • Soak until the root zone is wet well below the surface, then let the top few inches dry before the next watering
  • Plant in full sun in average, well-drained soil, since goldenrod does not take full shade
  • Space clumps so air moves through the stems, which helps limit powdery mildew and rust
  • Extend the drip line as rhizomes spread, or divide clumps every two or three years to keep them in bounds

Through the seasons

Water new plants regularly through their first summer so the rhizomes spread and root in. Established goldenrods still want moderate water through summer, when stems lengthen ahead of the bloom from July into October. Deadheading spent flowers brings more bloom and limits self-sowing. After fall bloom the plant heads into its winter rest, and its water use drops. WUCOLS gives goldenrod a moderate water rating on the north-central coast, in the Central Valley and on the south coast. In South Inland the rating is high water. WUCOLS has not evaluated it for the high desert or the low desert. On the coast and in the Central Valley, winter rain covers the cool months.

In pots

Shorter goldenrods suit a large pot, and the container also keeps their spreading rhizomes in bounds. Fill it with a well-drained mix, and make sure the pot has drainage holes. In summer, probe the mix 2 inches deep every few days, and more often when South Inland heat sets in. Pour until water escapes through the holes, then empty the saucer. When roots fill the pot, it dries out fast, so divide the clump at that stage. Once fall bloom is over, water only if the mix has dried and no rain has done the job.

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

Goldenrod: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.781.24––
Feb0.530.650.811.39––
Mar0.871.091.152.08––
Apr1.181.521.42.58––
May1.462.081.613.12––
Jun1.612.481.743.67––
Jul1.612.671.984.02––
Aug1.492.391.863.72––
Sep1.241.81.492.98––
Oct0.871.181.152.13––
Nov0.470.560.841.44––
Dec0.310.340.651.09––
Year1217.1115.529.46––

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 moderate water in the Central Valley, like goldenrod. 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 goldenrod 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 goldenrod, 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 goldenrod in summer?

In July, established goldenrod 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 goldenrod need per day?

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

Yes. WUCOLS rates goldenrod 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, 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 goldenrod cause hay fever?

No. Goldenrod is wrongly blamed for hay fever. The allergy comes from the wind-borne pollen of other plants, such as ragweed, which goldenrod is sometimes confused with.

Is goldenrod invasive?

Some species spread aggressively by rhizomes and seed in good conditions. Divide clumps every two or three years, and cut off flower heads before the seed ripens. In the U.S. goldenrods are generally not considered invasive.

Why does my goldenrod have white powder on its leaves?

That is powdery mildew, one of the common goldenrod problems along with rust and leaf spot. Space plants for air flow and water the soil, not the leaves. Some cultivars are listed as disease resistant.

Do deer eat goldenrod?

Goldenrod is generally deer resistant. Birds eat its seeds, which adds to its wildlife value.

Does goldenrod grow in shade?

Goldenrod grows best in full sun and tolerates light shade. It does not tolerate full shade, so pick the sunniest spot you have.

How do I get more flowers on goldenrod?

Deadhead spent flower clusters to encourage additional bloom. Give the plant full sun and steady moderate water through summer. Avoid soggy soil, which leads to root rot.

More plant watering guides

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Sources