WateringTimesWatering plan, $19
Myosotis scorpioides, WUCOLS IV

How often to water forget-me-not in California

In July in the Central Valley, established forget-me-not 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. This is the water forget-me-not, a low, creeping perennial of stream banks and wet meadows with sky blue, yellow-eyed flowers. It spreads by rhizomes into a soft mat and grows best in organic soil that stays moist, even right at a pond edge. It is not a plant for dry, sunbaked ground.

PerennialRated for 4 of 6 zones

How often to water forget-me-not, 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 forget-me-not 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 just 1 inch down around the mat means a forget-me-not needs water
  • Leaves flagging at midday in full sun, with dry soil below, show the mat has run short
  • Crisp brown patches in an otherwise healthy mat mark spots where the soil dried out
  • Orange rust spots on the leaves of a crowded, constantly damp mat call for better air flow and less overhead watering
  • A white powdery film on leaves in shade is powdery mildew, which is not cured by more water

How to water it

  • Water at the base of the mat with a soaker hose or gentle stream so the soil stays evenly moist
  • Wet the soil about a foot deep each time, and water again before the top inch dries in summer
  • Plant in organic, moisture-holding soil such as a pond margin or heavy clay, where it thrives
  • Water early in the day if you use sprinklers, so the leaves dry quickly and rust has less chance
  • Widen the watered area as rhizomes spread the mat, or edge the bed to keep it in bounds

Through the seasons

Keep new plants moist from the day they go in, since forget-me-not never likes to dry out. Established mats flower from summer into early fall and keep their leaves through mild winters. Hot, dry spells are the season of most need, especially in the Central Valley and South Inland. Winter rain usually covers the cool months on the coast and in the valley. WUCOLS rates forget-me-not moderate water in South Inland, on the south coast, in the Central Valley and on the north-central coast. WUCOLS has not evaluated it for the high desert or the low desert.

In pots

Forget-me-not grows well in pots and even in water garden containers. In a pond, sink a pot so up to 3 inches of water covers the crown, which also keeps it from spreading. In an ordinary patio pot, keep the mix moist and check it daily in summer heat. A saucer can stay partly full in hot weather, since this plant tolerates wet roots. Move pots into light shade during heat waves, and water less in winter without ever letting the mix dry.

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

Forget-Me-Not: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.370.40.780.78––
Feb0.530.650.810.87––
Mar0.871.091.151.3––
Apr1.181.521.41.61––
May1.462.081.611.95––
Jun1.612.481.742.29––
Jul1.612.671.982.51––
Aug1.492.391.862.33––
Sep1.241.81.491.86––
Oct0.871.181.151.33––
Nov0.470.560.840.9––
Dec0.310.340.650.68––
Year1217.1115.518.41––

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 forget-me-not. 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 forget-me-not 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 forget-me-not, 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 forget-me-not in summer?

In July, established forget-me-not 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 6 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 forget-me-not need per day?

In July in the Central Valley, established forget-me-not 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 forget-me-not change across California?

Yes. WUCOLS rates forget-me-not 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, moderate 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.

Can forget-me-not grow in a pond?

Yes. This species is a marginal water plant that grows in up to 3 inches of standing water. Plant it at the water line or in a pot set just below the surface.

Will forget-me-not spread through my garden?

It creeps by rhizomes into dense colonies and also self-seeds. It is not usually aggressive, but edge the bed if you want it contained. Divide clumps in early spring for new plants.

Why are my forget-me-not leaves white and powdery?

That is likely powdery mildew, which favors shade and mild temperatures. Thin crowded clumps and give the bed more sun. Unlike rust, it does not need wet leaves to spread.

Does forget-me-not need full sun?

It grows in full sun or part shade. In hot inland gardens, part shade keeps the soil moist longer and the mat greener. Deep shade invites mildew.

How do I keep forget-me-not blooming?

Pinch young plants to make them bushier, and keep the soil evenly moist through the summer bloom. The dwarf cultivar 'Semperflorens' has more flowers and a longer bloom time.

More plant watering guides

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Sources