WateringTimesWatering plan, $19
Onoclea sensibilis, WUCOLS IV

How often to water sensitive fern in California

In July in the Central Valley, established sensitive fern 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. Sensitive fern is a large deciduous fern native to eastern North America and eastern Asia that thrives in moist woodland soil. Its name refers to how poorly it handles frost and drought. It spreads by creeping rhizomes into broad patches, its fronds turn gold in fall, and shorter fertile fronds turn brown as summer goes on.

PerennialRated for 3 of 6 zones

How often to water sensitive fern, 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 sensitive fern 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 drying an inch down in the patch in summer means sensitive fern needs water now
  • Fronds browning and shriveling in midsummer point to soil that is not staying moist
  • Fronds wilting on a hot, windy day suggest the root zone dried
  • Short brown fertile fronds in summer are normal, not a sign of thirst

How to water it

  • Keep the soil consistently moist with slow, deep watering
  • Water before the surface dries in warm weather
  • Plant in shade in rich clay or loam soil high in organic matter
  • Shelter it from cold or drying winds
  • Mulch with leaf litter to hold moisture

Through the seasons

Keep a new planting moist from the start. Established patches still need consistently moist soil, and fronds deteriorate as summer goes on in hot climates if the soil dries. Fronds turn gold in fall and die back for winter, then new ones unfurl in spring. In the Central Valley and on the north-central coast, WUCOLS gives sensitive fern a high water rating. On the south coast it carries a moderate water rating. WUCOLS has not evaluated it for South Inland, the high desert or the low desert.

In pots

Sensitive fern can grow in a wide, deep container in shade. Use a rich, moisture-holding mix. Water as soon as the surface begins to dry, soaking until water runs out. In summer, that may mean every day, since the fronds fade fast in dry mix. A saucer can stay under the pot in hot weather if the mix drains. In winter, after fronds die back, keep the mix just damp.

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

Sensitive Fern: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.60.640.78–––
Feb0.841.040.81–––
Mar1.391.741.15–––
Apr1.882.431.4–––
May2.333.321.61–––
Jun2.583.971.74–––
Jul2.584.271.98–––
Aug2.383.821.86–––
Sep1.982.881.49–––
Oct1.391.881.15–––
Nov0.740.890.84–––
Dec0.50.550.65–––
Year19.227.3815.5–––

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 sensitive fern. 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 JulyCardinal FlowerLobelia cardinalis hybrids and cvs. (CA 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 July

Similar plants that need less water 16

Rated lower than sensitive fern 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 sensitive fern, 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 sensitive fern in summer?

In July, established sensitive fern in loam needs a deep watering about every 3 days in the Central Valley and about every 7 days on the south coast. 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 sensitive fern need per day?

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

Yes. WUCOLS rates sensitive fern separately for each of the six California climate zones: high water in the North-Central Coastal zone, high water in the Central Valley zone, moderate water in the South Coastal zone, not evaluated 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.

Why is it called sensitive fern?

The name refers to its poor tolerance of frost and drought. Fronds fade quickly in dry soil. Keep it moist and sheltered.

Why are my sensitive fern fronds brown in summer?

Fronds deteriorate in hot climates when the soil is not kept moist. Water more steadily and add shade. Short fertile fronds turn brown naturally.

Does sensitive fern spread?

Yes, it spreads by creeping rhizomes and by spores. It can form broad patches. Give it room in a moist, shady area.

Can sensitive fern grow in sun?

It thrives in shade. Sun dries both soil and fronds. Plant it where shade lasts all day.

Can I use sensitive fern fronds indoors?

Yes, the leaves can be dried for indoor arrangements. Pick healthy fronds. Leave enough to keep the patch growing.

More plant watering guides

Soft Shield FernBlack CottonwoodCarolina PoplarOrnamental RhubarbWeeping WillowPeking WillowWillowStevia

Sources