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Boston Fern Pests And Diseases: Common Bugs & Diseases+How To Fix

Boston ferns are popular houseplants with stunning fronds. But one problem they might face is pests and diseases.  

Boston ferns are vulnerable to pests like mealybugs, scales, fungus gnats, and caterpillars. The pests suck out nutrients from your plant, leading to wilted and yellow leaves. Whereas diseases such as pythium root rot and Rhizoctonia aerial blight can severely damage the plant if left untreated.

Overwatering, excess humidity, and unsuitable conditions will attract pests and diseases to your plant.

Using insecticides, Neem oil, and rubbing alcohol solutions can help the plant get rid of pests and diseases.

When infested, the plant’s leaves indicate that pests and diseases have affected them. If you notice any such signs, take immediate steps to save your plant.

This article will discuss the different types of pests and diseases that can attack your Boston fern and help you identify ways to prevent and remove them before it’s late.

Boston fern white spots

I have done my best to address all of your concerns in the article below. However, if you still have any questions or are confused about the article, you can receive personalized one-on-one assistance from me by leaving a comment below. I will respond to your comment within a few hours.

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What are the common bugs on Boston ferns?

If you notice that your Boston fern looks dull and weak, inspect the plant to see whether it has pests.

Look for any signs of pests, as they can be one of the reasons your plant is not well.

Unfavorable conditions such as damp soil, over-fertilization, unsuitable temperature, or humidity can encourage pests toward the plant.

Lets us now discuss all the pests that can attack your Boston ferns.

The most common pests on Boston ferns are mealybugs.


mealybugs identification
mealybugs identification

They are tiny and soft insects with cottony or white downy substances covering their bodies.

They usually attack the lower surfaces and the plant’s roots and leave behind a sticky, syrup-like residue known as honeydew or sooty mold on the affected surfaces of the plant.

If mealybugs infest Boston ferns, the leaves wilt, turn yellow or brown, and the roots begin to weaken. 

Fungus Gnats

Gnats identification
Gnats identification

Fungus gnats are problem-causing insects on Boston ferns resulting from overwatering.

They have black bodies that can easily blend with the soil.

They can also fly, so it is often hard to catch and cure them.

Fungal gnats are found on the underside of the leaf surfaces of Boston ferns or in the soil surrounding the plant.

Their larvae are small worms with blackheads and transparent bodies.

The larvae stay inside the soil and create web-like structures along the soil surfaces. 

The larvae feed on the roots, lower stem tissues, and leaves that contact the soil.

The damage caused by larvae includes wilted and yellow leaves. 

The larvae damage the plant’s root system, making it vulnerable to many other diseases, which can cause more severe damage to the plant’s health. 


Scales identification
Scales identification

Scales are tiny pests that are difficult to spot on Boston ferns.

They are hard-bodied insects with legs, so they don’t move around.

They are found in brown, black, or white color.

They stay on the stems and fronds of Boston ferns and feed on their tender leaves. 

Scales secrete honeydew which results in the growth of black mold on the stems and leaves of the plant.

Stunted growth and wilted leaves are all indications of scale infestation. 


Fiddle leaf fig 20 2
caterpillars identification

Caterpillars usually infest Boston ferns that are grown outdoors.

However, some species of caterpillars, such as the Florida fern caterpillar, are troublesome to indoor Boston ferns.

They are easy to spot.

These pests are larvae of moths.

They lay their eggs on the fronds of Boston ferns. 

Once the larvae come out from the eggs, they eat the leaves.

Their infestation will cause the leaves to appear ragged on the edges or develop holes along the center of the leaves. 

Snails and slugs

Two more pests that affect Boston ferns are snails and slugs.

Like caterpillars, they eat the juicy, tender leaves of Boston ferns.

They feed and reproduce at night when the temperature is cool.

They hid in the leaves during the daytime to protect themselves from the hot afternoon sun.

You will notice most of the damage in the morning when you water the plants.

Stay awake at night if you want to catch the snails or slugs from the fronds by hand.

Another way to remove snail or slug is by surrounding the plant with snail or slug bait.

How to get rid of pests on Boston ferns?

Boston fern neem oil

Once you have identified the pests, you need to find ways to remove them from your plant.

Pests spread rapidly, and even a little delay in treatment can put your plant at risk.

Let us now discuss the steps involved in creating a Boston fern from pest infestation.

Isolate your plant

Before you start the treatment, isolate your Boston fern in one place to prevent the spread of bugs to other houseplants. 

Prune off the infected leaves and parts

You should prune the infested leaves and other damaged parts of the plant so the bugs from these areas will not be able to infect the plant anymore. 

Use sharp and sterile pruners for pruning your plant.

Ensure that you don’t cut more than 25% of the leaves at once.

This will put the plant under stress. 

Start your treatment

This step will start the methods to remove pests from your plant.

You can use both organic and chemical methods to remove pests, although I suggest using the organic method first.

The organic method is best as it won’t harm your plant.

If the organic method fails, you can adopt a chemical treatment. 

Handpick the visible pests

Alocasia bugs

If the pests are visible to naked eyes, wear gloves and handpick them.

But if the pests are too tiny, you need to look for other ways to remove them.

Wash the plant in running water

Once you have identified the bugs, you can give a good bath to your plant by placing it under running water.

You need to wash the plant a few times to remove all the insects. 

Ensure you don’t overwater your plant, as this can make the soil soggy, leading to many other problems.

Once you wash the plant, keep it in bright indirect sunlight and allow the soil to dry out completely.

If the pests are still there, you need to adopt other methods for removing them.

Use a rubbing alcohol solution.

In this step, prepare a rubbing alcohol solution mixing:

  • 1 part of rubbing alcohol
  • 3 parts of water

Dip a cotton ball in it and apply it all over the affected spots.

This solution will remove the sticky pests from the plant.

Use insecticidal soaps

Natria 706230A Insecticidal Soap Organic Miticide, 24 oz, Ready-to-Use

Insecticidal soaps are natural ways to remove pests without harming the plant.

They will be great on Boston ferns as it is nontoxic. 

You can prepare an insecticidal soap by mixing 4 cups of water and 1 tablespoon of liquid soap.

Pour the solution into a spray bottle and apply it over the plant once a week. 

If the infestation is severe, you must spray it more often.

Use the spray in medium light and average temperatures.

Use Neem oil solution.

Neem oil is one of the effective and nontoxic ways for removing pests from the plant.

It damages the hormones of the pests, which prevents their normal functioning.

As a result, the bugs fail to feed and eventually die back.

Neem oil does not work well on insects that have scales.

You can make your Neem oil solution by adding:

  • 1 gallon of water
  • 1 tablespoon of liquid soap
  • 1 tablespoon of Neem oil

Fill the solution in a spray bottle and apply it over the plant for a few days. 

If you don’t have neem oil, you can also use horticulture oil to remove bugs.

It works well on soft-bodied insects. 

It evaporates fast and does not cause damage to the plant.

Make sure you don’t apply this oil in too high or too low temperatures as such conditions will stress the plant. 

Also, avoid using the oil in high humid conditions as this will this won’t allow the oil to evaporate quickly.

Use sticky traps

Houseplant bugs

You can use sticky traps for flying bugs, such as fungal Gnats.

You can buy sticky traps online or prepare yourself by applying petroleum jelly on yellow cardboard.

Sticky traps are useful as the bugs will get attracted to them by looking at the yellow color.

Use pyrethrum powder

You can use pyrethrum to remove bugs from the plant.

Pyrethrum is a botanical treatment that kills pests. 

Use pyrethrum powder directly on the plant or dilute it in water and use it as a spray over your plant.

You need to apply it for a few days until the pest gets eliminated.

Use organic insecticides

You can use organic insecticides such as Diatomaceous Earth for removing bugs from the plant.

It restricts the pests’ movement, causes dehydration, and kills them. 

Make sure that honeybees and butterflies do not come near the plant as this insecticide is toxic for them.

Use pesticides

Natria 707100 Insect, Disease, & Mite Control for Indoor and Outdoor Plants, 24-Ounce, Ready-to-Use

You can use pesticides such as rotenone for killing bugs from your plant.

This pesticide will paralyze the bugs and kills them very fast. 

Maintain a distance while using this pesticide as it can be harmful to the eyes.

Spray the pesticides once a week to remove all the pests from your plant.

What are the common diseases on a Boston fern?

Boston fern dying

Boston ferns can succumb to diseases when stressed due to unfavorable growing conditions.

In the worst scenario, a disease can even kill your plant.  

When a disease affects the plant, it slows down its growth, becomes spindly, leaves turn brown or yellow, or powdery blotches become visible in the leaves. 

The best thing to outbreak disease is by providing the plant with a suitable growing environment.

Let us now learn about the diseases in detail.

Pythium root rot

Many varieties of Boston ferns such as Bostoniensis, Florida ruffle, Dalla, and compacta are subjected to Pythium root rot. 

The fronds grow close together, making the plant dense.

This situation restricts the airflow around the fronds, encouraging the growth of fungal diseases. 

Also, the plant develops this disease if it is exposed to low light and low humidity conditions or when the growing medium is wet.

The disease will cause the fronds of your Boston fern plant to turn greyish.

Pythium root rot can stunt your plant’s growth and eventually kill it. 

How to fix it?

If your Boston fern has developed Pythium root rot, transplant the diseased plant into a new sterile potting soil and new pot. 

Apply fungicides to the plant and prune off the dead and decayed parts. 

You can use a product known as Bon-neem that has both fungicidal and insecticidal agents together.

To avoid such diseases, always buy pathogen-free plants. 

Rhizoctonia aerial blight

Rhizoctonia aerial blight or blight fungus is a fungal disease that will attack your Boston fern in hot and humid conditions. 

This pathogen lives inside the soil, but its spores can multiply on the fronds and travel through the air.

To end the disease, you need to treat both the leaves and the soil.

The disease causes brown, wet spots on the crown of the plant.

These brown spots merge and form a web-like material covering the entire plant if not treated on time. 

How to fix it?

Bring your plant outside and spray it with a fungicide containing methyl compounds to treat blight fungus.

Apply the fungicide as per the age and size of the plant. 

You can also drench the soil with the same fungicide to kill the pathogens.

Prune off the dead and damaged leaves that are infected with this disease. 

If the soil condition is very poor, you need to repot the plant in new soil and a new pot.

Make sure to throw out the infected soil and pot.

How to prevent pests and diseases from Boston ferns?

Boston fern 6

You can prevent pests and diseases in your Boston fern by taking care of its basic growing requirements.

  • Provide your plant with bright, indirect light for at least 2-3 hours every day. Do not keep them in low light as such conditions will attract pests and diseases to the plant. If the Boston fern doesn’t get enough natural light, use artificial light.
  • Use well-drained soil and a pot with drainage holes for your Boston ferns to prevent overwatering. 
  • Also, do not keep your plant dehydrated since a thirsty and weak plant is an easy target for pests like spider mites and other diseases. Keep the soil moist but not soggy. Water the plant when the top 1-2 inches go dry.
  • Maintain sufficient humidity around the plant. You can use a humidifier device or group your plant with other houseplants to increase the humidity level around it. 
  • Make sure that the surrounding area around the plant has good air circulation.
  • Keep the leaves of your plant clean and dust-free.
  • Spray the plant with Neem oil solution every month to prevent pests and diseases.
  • Observe your plant daily and ensure that it receives all the ideal growing conditions. Remember that pests and diseases will never attack a healthy plant.

Reference: University of FloridaThe University of Arkansas DivisionTexas A&M University SystemThe University of GeorgiaUniversity of New HampshireWikipediaThe Royal Horticultural Society.

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