WateringTimesWatering plan, $19
Matteuccia struthiopteris, WUCOLS IV

How often to water ostrich fern in California

In July in the Central Valley, established ostrich fern 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. Ostrich fern is a deciduous woodland fern that rises each spring into vase-shaped crowns of tall, feathery green fronds. It comes from cool, moist woods and spreads by underground runners into colonies. It prefers soil that never fully dries, and it handles wet ground far better than drought.

PerennialRated for 4 of 6 zones

How often to water ostrich 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 ostrich 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 dry 2 inches down under the mulch around an ostrich fern crown signals that the colony needs a soak
  • Frond tips and edges browning in summer warrant a soil check, since this fern wants steady moisture
  • Fronds flagging in afternoon sun over dry soil suggest the bed needs more shade as well as water
  • Fronds yellowing over ground that stays waterlogged and sour can point to stagnant water rather than thirst
  • Stiff brown fertile fronds standing in the center of each crown through winter are normal, not a sign of drought

How to water it

  • Water at the base of the crowns with a soaker line or slow hose so the whole colony gets wet, not just the oldest clump
  • Soak the soil about a foot deep around the crowns, then water again once the top inch or two starts to dry
  • Spread leaf mold or shredded bark between the crowns to keep the soil cool and slow evaporation
  • Plant in rich soil high in organic matter in part or full shade, working compost into fast-draining sand
  • Widen the watered area as runners raise new crowns beyond the original planting

Through the seasons

A new ostrich fern needs evenly moist soil through its first growing season while its crowns and runners settle in. Established colonies still want moisture from spring until the fronds fade, because this fern prefers constant moisture. Fiddleheads unfurl in spring, the green fronds die back in fall, and the brown fertile fronds stand through winter. Dormant crowns need little water, and winter rain covers the cool months on the coast and in the Central Valley. WUCOLS rates ostrich fern moderate water on the north-central coast, in the Central Valley and on the south coast. It rates high water in South Inland. WUCOLS has not evaluated it for the high desert or the low desert.

In pots

Ostrich fern can live in a large, deep container in shade, though its runners crowd a pot within a few seasons. Feel the mix an inch or two down every few days in summer, and daily during inland heat waves. Water slowly until it flows from the drainage holes, then tip out the saucer. Once the fronds die back in fall, keep the dormant crowns in barely damp mix. Divide a crowded pot in spring as the fiddleheads appear.

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

Ostrich Fern: 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 ostrich fern. 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 ostrich fern 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 ostrich 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 ostrich fern in summer?

In July, established ostrich fern 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 ostrich fern need per day?

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

Yes. WUCOLS rates ostrich fern 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.

Can ostrich fern grow in full sun?

It tolerates sun only where summers stay cool and the soil stays moist. Elsewhere, plant it in part or full shade. Shade also slows how fast the bed dries between soakings.

Why is my ostrich fern spreading?

It sends out underground runners that raise new crowns away from the parent clump. Moist, rich soil makes that spread faster. Dig out unwanted crowns in spring, or edge the bed to hold the colony in place.

Why do ostrich fern fronds die back in fall?

Ostrich fern is deciduous, so its green fronds yellow and collapse as it goes dormant. That is a seasonal change, not thirst. Cut back on water once the fronds are down, and expect new fiddleheads in spring.

Can ostrich fern grow in a wet spot or rain garden?

Yes. It tolerates wet soil and suits rain gardens and damp, shaded low spots. Water that soaks in and drains after storms suits it better than a puddle that sits for days.

Are ostrich fern fiddleheads edible?

Yes, the young fiddleheads can be eaten once cooked. Pick only a few from each crown so the plant still raises a full set of fronds. A crown stripped of fiddleheads has fewer fronds to feed its roots that year.

More plant watering guides

Krauter Vesuvius Purple PlumFlower Carpet Appleblossom RoseFlower Carpet Red RoseFlower Carpet Coral RoseNarrow-Leafed Bird of ParadiseAmerican GrapeNatal LilyBear's Breech

Sources