Plant Care ET Fern

ET Fern

About ET Fern

ET Fern is a super rare houseplant 🌿 that needs regular watering to thrive. They do best in abundant sunlight ☀ and should be less than 3 feet from a window.

ET Fern likes soil that is well draining. Your plant shouldn't need added fertilizers if you repot each time it doubles in size.


Polypodium formosanum 'Cristatum'

Also known as

Frog Foot Fern, Caterpillar Fern and Grub Fern

How to care for ET Fern


How often to water your ET Fern

Water needs for ET Fern
0.5 cups
every 9

ET Fern needs 0.5 cups of water every 9 when it doesn’t get direct sunlight and is potted in a 5" pot located in Philadelphia, Pennsylvania.

Use our water calculator to personalize watering recommendations to your environment or download Greg for more advanced recommendations for all of your plants.

Calculate water needs of ET Fern

Water 0.5 cups every

Does your plant get direct sunlight?

Select the pot size


Check the growing potential in your area

A plant's growing potential is determined from its location, the time of year, and current local weather.

Plant care guide for ET Fern in Philadelphia, Pennsylvania

Philadelphia, Pennsylvania

43% Low

Growing ET Fern in Philadelphia right now

Light needs for plant ET Fern in Philadelphia, Pennsylvania

Plant growth potential is currently very low 📉

December 1st, 2021

Sunlight intensity as measured by “net radiation” in Philadelphia is currently very low 📉.

The availability of high quality sunlight in your home impacts ability for plants to thrive and is key in…

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Light needs for plant ET Fern in Philadelphia, Pennsylvania

Sunlight intensity will decrease by 29% ☀️

November 30th, 2021

Philadelphia is trending towards lower sunlight intensity!

The amount of sunlight in Philadelphia is expected to decrease by 29% over the next 2 weeks to an average of 6.8 megajoules of energy per…

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Light needs for plant ET Fern in Philadelphia, Pennsylvania

Daylight will decrease by 1.1 hours 📉

November 30th, 2021

This month, Philadelphia is getting an average of 8.1 hours of clear sky sunlight per day.

Hours of daylight will decrease by 10.8% over the next two weeks. Your plants will get 9.2 total hours of…

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Finding light for ET Fern in your home

Light needs and placement for plant ET Fern: 3ft from a window
3ft or less from
a window

ET Fern may have difficulty thriving, and will drop leaves 🍃, without ample sunlight.

Place it less than 3 feet from a south-facing window to keep it happy during this time of reduced sunlight intensity in Philadelphia, Pennsylvania ⛅.


How to fertilize ET Fern

Nutrient, fertilizer, and repotting needs for ET Fern: repot after 2X growth

Most potting soils come with ample nutrients which plants use to produce new growth.

By the time your plant has depleted the nutrients in its soil it’s likely grown enough to need a larger pot anyway.

To replenish this plant's nutrients, repot your ET Fern after it doubles in size or once a year—whichever comes first.

When to repot ET Fern

Nutrient needs for plant ET Fern in Philadelphia, Pennsylvania

Is this a good time of year to repot? No ⏳

November 30th, 2021

The growing potential in Philadelphia is very low 📉.

Repotting in late fall or winter when the day lengths are shorter can be very stressful for a plant and cause it to go into shock.

It's bes…

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Water Needs
Sunlight Needs

Care Summary for ET Fern

ET Fern

ET Fern

Greg recommends:


0.5 cups every 9 days


< 3ft from a window


Repot after 2x growth

Based on your location in Philadelphia, Pennsylvania, the 4” pot your plant is in, and that it doesn’t get direct sunlight.

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