WateringTimesWatering plan, $19
Carex aquatilis, WUCOLS IV

How often to water water sedge in California

In July on the north-central coast, established water sedge in loam needs a deep watering about every 9 days: about 1.5 gallons each time for a plant 2 feet across, about 1.1 gallons a week. Water sedge is a sod-forming, grasslike sedge that grows 6 inches to more than 3 feet tall, with triangular stems and thick rhizomes. In the wild it fills wet meadows, stream banks and pond edges. It wants full sun and soil that stays damp, and its spreading roots hold shorelines and banks together.

PerennialRated for 2 of 6 zones

How often to water water sedge, 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 water sedge 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 among the stems during summer signals that water sedge needs water
  • Leaf tips browning and the patch turning tan early in summer can indicate the root zone has dried
  • Thin, sparse growth that stops spreading can follow repeated dry spells
  • Patches dying back after more than a month or two under deep water suggest flooding beyond what it tolerates

How to water it

  • Water the whole patch with a soaker or by flooding a low basin, since it spreads as a sod
  • Keep the soil saturated while plants establish, with no more than 1 to 2 inches of standing water
  • Plant in full sun, since water sedge does not tolerate shade
  • Group it at a pond margin, swale bottom or other spot that stays damp
  • Extend water outward as rhizomes push the patch into new ground

Through the seasons

Keep new plants saturated until roots and rhizomes are well set and the leaves are about a foot tall. Established stands still want consistently moist soil, and they can sit through a month or two of submersion. Water sedge stays green late into summer and flowers from late spring into early fall. On the north-central coast and in South Inland, WUCOLS rates water sedge moderate water. WUCOLS has not evaluated it for the Central Valley, the south coast, the high desert or the low desert.

In pots

Water sedge can grow in a large tub or a pot sunk at a pond edge, set in full sun. Keep the mix wet through the growing season, checking every day or two in summer heat. A saucer kept partly full suits it in the growing season. Divide the clump when rhizomes circle the pot. In winter, let the mix stay moist rather than flooded. Cut back old, tattered leaves in late winter before new growth starts.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Water Sedge for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Water Sedge as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Water Sedge: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.37––0.78––
Feb0.53––0.87––
Mar0.87––1.3––
Apr1.18––1.61––
May1.46––1.95––
Jun1.61––2.29––
Jul1.61––2.51––
Aug1.49––2.33––
Sep1.24––1.86––
Oct0.87––1.33––
Nov0.47––0.9––
Dec0.31––0.68––
Year12––18.41––

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 not evaluated in the Central Valley, like water sedge. Plants that drink alike can share one valve and one schedule.

Lilyleaf LadybellsAdenophora liliifolianot rated, Central Valleyno Central Valley ratingArnicaArnica montananot rated, Central Valleyno Central Valley ratingFrilly BergeniaBergenia ciliatanot rated, Central Valleyno Central Valley ratingCabbage on a StickBrighamia insignisnot rated, Central Valleyno Central Valley ratingBasket PlantCallisia fragransnot rated, Central Valleyno Central Valley ratingForest SedgeCarex sylvaticanot rated, Central Valleyno Central Valley ratingUmbrella DracaenaDianella ensifolianot rated, Central Valleyno Central Valley ratingRusty FoxgloveDigitalis ferrugineanot rated, Central Valleyno Central Valley ratingBig-Flowered FoxgloveDigitalis grandifloranot rated, Central Valleyno Central Valley ratingWoolly FoxgloveDigitalis lanatanot rated, Central Valleyno Central Valley ratingSunset FoxgloveDigitalis obscuranot rated, Central Valleyno Central Valley ratingMale FernDryopteris filix-masnot rated, Central Valleyno Central Valley ratingAlpine Sea HollyEryngium alpinumnot rated, Central Valleyno Central Valley ratingPurple SpurgeEuphorbia dulcisnot rated, Central Valleyno Central Valley ratingQueen of the MeadowFilipendula ulmarianot rated, Central Valleyno Central Valley ratingDropwortFilipendula vulgaris (Filipendula hexapetala)not rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes water sedge, 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 water sedge need per day?

In July on the north-central coast, established water sedge needs about 0.2 gallons a day for a plant 2 feet across and about 0.7 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 water sedge change across California?

Yes. WUCOLS rates water sedge separately for each of the six California climate zones: moderate water in the North-Central Coastal zone, not evaluated in the Central Valley zone, not evaluated 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 water sedge grow in standing water?

Yes, it handles saturated soil and can survive a month or two underwater. While plants are young, keep standing water to an inch or two. Fluctuating water levels while it settles in can even speed its spread.

Does water sedge spread?

Yes, it spreads mainly by thick, long rhizomes and forms sod. That makes it good for holding banks against erosion. Plant it where spreading is welcome.

Can water sedge grow in shade?

No, it is shade intolerant and prefers open, sunny ground. Under trees it thins and stops spreading. Pick the sunniest wet spot you have.

Does water sedge have pests?

No pests or problems are known for it. Waterfowl and wildlife graze it and use it for cover. Damage usually means grazing, not a water problem.

Is water sedge a grass?

It looks grasslike but is a sedge, with triangular stems. Its flower spikes have male spikes above and female spikes below. It is wind pollinated.

More plant watering guides

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Sources