WateringTimesWatering plan, $19
Asplenium nidus (N. australasicum) (shade), WUCOLS IV

How often to water bird's nest fern in California

In July in the Central Valley, established bird's nest 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. Bird's nest fern is a tropical fern with broad, glossy, strap-shaped fronds arranged in a funnel-shaped rosette. Each frond has a dark midrib and wavy edges. In the wild the funnel catches falling leaves and makes its own compost. It wants shade, moist but porous soil, humidity and protection from cold below about 40 degrees.

PerennialRated for 4 of 6 zones

How often to water bird's nest 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 bird's nest 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

  • When the top inch of soil or mix feels dry, bird's nest fern is ready for water
  • Fronds browning at the tips and edges can point to dry air or a root zone that dried out
  • Fronds turning yellow or growth stalling in bright sun show it needs more shade
  • A soft, collapsing center in soggy mix points to too much water and poor drainage
  • Spotted or damaged fronds after a pesticide spray reflect chemical injury, not thirst

How to water it

  • Water bird's nest fern at the soil around the rosette, wetting the root zone evenly
  • Keep the soil lightly moist, watering again when the top inch dries
  • Plant in rich, porous soil high in organic matter, in full or dappled shade
  • Mulch with leaf mold to hold moisture and add organic matter
  • Handle the fragile fronds gently when moving drip lines or cleaning around the plant

Through the seasons

Keep a new bird's nest fern evenly moist while it settles in, in a sheltered, shaded spot. Established plants need steady moisture and humidity through the warm months. Growth slows in cool weather, and the fern will not survive temperatures below about 40 degrees, so outdoor plants need a frost-free site. WUCOLS rates bird's nest fern moderate water on the north-central coast, in the Central Valley and on the south coast. In South Inland it rates high water. WUCOLS marks it as not suited to the high desert or the low desert.

In pots

Bird's nest fern is most often grown in a pot, indoors or on a shaded patio. Use a container with drainage holes and a rich, porous fern mix. Water when the top inch is dry, and set the pot on a tray of pebbles and water to raise the humidity. Never let the pot sit in standing water. Bring it inside before nights drop toward 40 degrees, and keep it away from heaters and drafts.

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

Bird's Nest 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 bird's nest 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 bird's nest 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 bird's nest 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 bird's nest fern in summer?

In July, established bird's nest 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 bird's nest fern need per day?

In July in the Central Valley, established bird's nest 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 bird's nest fern change across California?

Yes. WUCOLS rates bird's nest 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 suited to this region in the High and Intermediate Desert zone, not suited to this region in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Can bird's nest fern grow outdoors in California?

Only in shaded, frost-free spots, since it will not survive below about 40 degrees. Most gardeners grow it in a pot that can come inside in winter.

Why are my bird's nest fern fronds turning yellow?

Too much sun is a common cause, and it can also stall growth. Move the plant into shade before changing your watering.

How do I raise humidity for bird's nest fern?

Stand the container on a pebble-filled tray with water kept below the pot's base. Keep it away from heater vents, which dry the air.

Can I spray bird's nest fern for pests?

Be careful. The fronds can be damaged by chemical insecticides. Pick off slugs and snails, and wipe scale or mealybugs away by hand.

Can you overwater bird's nest fern?

Yes. It likes moist mix but needs drainage, and soggy roots can rot. Water when the top inch dries, not on a fixed habit.

More plant watering guides

Saucer MagnoliaWestern CrabappleCrabappleAppleTree LavateraOstrich FernLemon BalmPurple Moor Grass

Sources