Blue Star Fern | Plant Care Guide

Blue Star Fern

Blue star fern (phlebodium aureum) is a beautiful green-blue color plant fern with elongated fronds. If you are looking for a fern that is relatively low-maintenance and thrive in lower-light conditions, blue star might be an astute choice.

This fern is an epiphytic fern which is a member of oak family. Also known as the Golden Polypody, blue star fern is considered one of the most powerful air-purifying indoor plants. The leaves of this fern do not shed when they get old. Instead, they branch into fingers and retain the fern’s beauty.

Botanical NamePhlebodium aureum
Common NameBlue Star Fern, Golden Polypody
Size12 inches tall and 12 inches wide
DifficultyEasy
Pet FriendlyYes. Non-toxic to pets
Air CleanerYes

Blue Star Fern Origin

Blue star fern comes from the tropical rain forests of South America, where it grows on trees without absorbing any moisture or nutrients from them. You can say it’s pretty similar to air plants in that way.

In addition to the tropical South American region, blue star fern can be also found in North America. However, unlike most other plants, it doesn’t grow in the soil here.

Instead, it grows on trees – in a harmless, non-parasitic way – thank to its creeping rhizome. This allows it to grow higher than most ground plants.

How to Care for Blue Star Fern

Whether you’re thinking of buying a blue star fern or have already bought one, the following care guide will help you keep your plant in the best shape throughout the year.

Light and Temperature

As mentioned earlier, this fern naturally grows on trees in the forests where most of the light is obstructed by the tree canopies. So, while your fern doesn’t need much light, it will need some for sure. As long as you don’t expose the fern to direct scorching sun, it will be fine.

Also note that tropical forests, where blue star grows naturally, have plenty of moisture. This means this plant can easily stay alive and healthy in locations that have high humidity, like your north facing kitchen or bathroom.

If you often mist the plant and the indoor air isn’t too dry, your living room can also be a good place to keep it. One of the nice things about blue star ferns is that they are not too demanding when it comes to temperature. During the summer and spring months, room temperature should be fine.

When the winter comes, make sure the room is not too chilly. Frost can wreak havoc on your fern so place it indoors if you live in a cooler climate. Remember, this fern loves low light. Place it somewhere it will direct receive sunbeams all day.

Water

Blue star ferns need constantly moist soil and a humid environment. However, make sure the water doesn’t stand in the pot for too long or the fern will suffer. The operating word here is “moist” and not “wet”!

If you are wondering about the best watering schedule for a blue star fern – there isn’t one. The amount of water your fern should get depends several factors like potting, season, and light. But to give you a general idea, water it once a week.

You should water the fern a little less during the non-growing season, and a little more during the growing season. The rule of thumb for watering a fern is, the soil should neither be dry nor soaked.

You can also mist your fern on a routine basis, especially if there is low humidity. In addition, you can keep the fern on a humidity tray.

One important thing to keep in mind while watering the blue star fern is, do NOT pour the water directly into the rhizome (heart). Water from the sides otherwise the fern may start to rot from the roots.

Fertilization

This fern doesn’t need a lot of additional fertilizer, but you may want to add some regular, diluted plant fertilizer during the growing season. Overfeeding is a big no-no.

Your fern will get all the essential nutrients from the new potting soil for 6-8 months after planting. After that, you will need to fertilize since the potting soil will have lost all its nutrients by that point.

Use a granular fertilizer or houseplant-specific liquid from early spring through early autumn months (March to November). For granular fertilizers, scatter ½ to 1 teaspoon on the top of the soil every six to eight weeks. If you are using a liquid fertilizer, mix it with water at half the strength recommended on the pack and pour it once a month.

You can use a synthetic fertilizer or an organic one depending on your budget and preference. Just make sure you don’t over-fertilize as it can lead to “burned” roots or brown frond tips.

# Note: Do not fertilize your blue star fern during the winter since it’s the non-growing season.

Pruning

Pruning is an important part of care for many plants and the same is true for blue star fern as well. To promote new growth, you have to remove damaged or dead foliage and errant stems. It will also help to prevent diseases and pests.

Now you can’t prune a blue star fern to promote specific growth, but pruning will help maintain a certain shape and size.

If you notice any damaged leaves, be sure to remove them right away. The best way to prune this fern is by snipping the thin stems. Don’t forget to sterilize your cutting tools first; just wipe them with rubbing alcohol beforehand.

Repotting

When ferns stay healthy, they outgrow their pots every few years. When you notice that your blue star fern seems to dry out very quickly or the rhizomes are pushing out against the side of the pot, it’s time to repot.

The first step would be to divide the plant. For this, you’ll need to remove the fern from its pot. Use a small plant saw or a sharp kitchen knife to cut the fern into two or more pieces. Each piece or “division” should have a portion of the plant’s root that’s attached to a portion of the shoot.

You will need to cut through the rhizomes – this is a necessary step so don’t worry about it. It will not hurt the fern in any lasting way. If you don’t want to cut, you can instead crack the root ball apart with your hands.

Once you have divided the plant, loosen the remaining roots with your fingers and plant them into individual pots. Remember, you need to maintain the same planting depth those roots had in their previous pot.

Then water the fern well and do not put any fertilizer in for the first 2 months after repotting. The new roots are tender and extremely sensitive to fertilizer salts.

Pests 

If you notice any leaf curl, leaf death, leaf spots, or browning on the fern, it could be due to the pests. Fungus gnats, thrips, mealybugs, aphids, and spider mites like to munch on blue star fern so be vigilant.

One effective way to ward off the pests is by using a houseplant pesticide, a water-and-soap mixture, or a neem oil spray. But before you use any of these solutions, remove the leaves that have already been damaged.

You will need to apply the pest-removal mixture every 4-6 days until all the pests are gone.

# Note: If you see any white spots on the rhizomes or the foliage, don’t worry, it’s common. Unless they are accompanied by signs of pests, white spots on a fern are nothing to worry about.

Diseases

The biggest reason a blue star fern becomes diseased is due to overwatering or over abundance of moisture. Here are some of the most common diseases that can plague this fern:

Mildews

Powdery and rust mildew are common and can be triggered by moisture. To prevent this, keep the leaves dry and make sure they receive a healthy amount of air.

Southern Blight

This is a kind of root fungus that can be fatal for your fern. This fungus likes moist and warm conditions – just like your blue star fern. The only way to prevent Southern Blight is to keep everything sterilized and sanitary. Make sure your potting media as well as other tools are super clean.

Root Rot

If the soil in your fern pot stays soggy for several hours, it can lead to rot in the roots. This is especially an issue with heavy soil.

How to Propagate Blue Star Fern

You can propagate this fern by dividing its bulbs, corms, tubers, or rhizomes. Rhizome is considered the easiest and fastest way to propagate. Here is what you need to do:

  • Clean and sterilize the tools which you’ll use to cut the plant
  • Cut a small portion of rhizome; it should have various leaves. Spread charcoal dust over them.
  • Take a pot or a container with soil in it
  • Transfer the rhizome in a way that the roots are lying (and not buried) on the surface of
  • the soil
  • Water it a bit just to dampen the soil

If the size of your fern seems to be exceeding the container, you can repot it. Spring season is the best time to repot blue star fern.

Frequently Asked Questions

You don’t really need to mist this fern since it doesn’t like high humidity.

Not really. Blue star ferns can quickly adapt to your average indoor humidity levels so a humidifier is not required. If the air moisture is less than 40% or more, proper watering will help make up the difference.

It is most probably due to over-watering or under-watering. If the fronds seem dry and brown, your fern has either been burnt by direct sunlight, exposed to dry air, or hasn’t received enough water.

If the leaves are dying in the crown of the fern, it indicates overwatering. To prevent this, make sure you only water it from the sides.

Yes, absolutely. Pruning is essential to remove the dead or damaged leaves as well as to maintain the size of the fern. If you don’t remove those dead leaves, they will start attracting all kinds of pests and diseases. Make sure to cut through the yellow growth, and only around crispy, brown foliage.

Yes! Epsom salts work wonders on all kinds of ferns including the blue star. If you want your fern leaves to get that deep, rich dark green color, a liquid fertilizer consisting of Epsom salts is a poignant choice.

You can just mix 1 tablespoon of Epsom salt with 1 gallon of water and use this solution on your ferns. This mixture is rich in magnesium which can help your plants flourish. Just make sure you either spray the solution or pour it from the sides.

The most visible sign that your fern is overwatered is wilted or yellowing leaves. Before you water the plant, touch the soil with your fingertips. Water it only if the soil surface seems slightly dry.

Overwatering also leads to fungal diseases and root rot in the ferns. As mentioned earlier, do not let the pot sit in water.

Final Thoughts

A blue star fern may look like a simple plant with a feather-like leaf structure, but that’s obviously not the case. Most people don’t know that ferns are one of the oldest living plant species in the world. Like many ferns, blue star also evolved hundreds of millions of years ago and continues to thrive today.

The bluish-green or bluish-gray fronds of the blue star fern can add a beautiful touch to any indoor space. When this fern is young, the fronds are uneven in shape and size. As the plant continues maturing, the fronds get larger with a more consistent and uniform structure.

Keeping a blue star alive and well is not that complicated once you get a grip on the care tips shared in this post. If you are looking to grow a fern inside your home, blue star fern certainly deserves your consideration.

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