Lemon button fern: Diseases and Remedies (2-minute Read)

NOTE: Lemon button fern may be referred to as Nephrolepis cordifolia ‘Duffii’ in this article, in fact, those are the same plants, Nephrolepis cordifolia ‘Duffii’ is the botanical name for Lemon button fern.

If you have struggled to keep a fern alive indoors before, then the lemon button fern may be the plant for you. The lemon button fern is a dwarf variety of the common Boston fern and goes by many names including button sword fern, erect sword fern, little-leaved sword fern, and fishbone fern.

It’s small size makes it perfect for growing indoors, and it’s known for being resilient and less finicky than some of its relatives. The small leaves of the lemon button fern give off a faint lemony scent during the spring and summer months, making it a refreshing addition to any home.

Why does my Nephrolepis cordifolia ‘Duffii’ roots have rot?

Root rot on your Lemon button fern (Nephrolepis cordifolia ‘Duffii’) can be fatal if not treated with care. For this reason, we strongly recommend that you follow our guide to keep your plant alive if the symptoms occur: Root soft and blackened.

Why does my Lemon button fern have gray mold spots?

Gray mold spots are a specific fungus that regularly harms flowers and spreads swiftly. If you notice any brown (or gray) spots, this fungus is probably to cause. You risk your plant dying if you ignore these warning indications.

Our Solution

The solution is quite logical when you know the cause of the problem. Most of the time, it is due to overwater of the Nephrolepis cordifolia ‘Duffii’. We advise you to remove the infected parts of the plant, cut off the infected roots and leaves, then repot your plant using sterile potting soil and a clean pot.

Why does my Lemon button fern have leaf spots?

Leaf We provide you with all the information you need to identify and save your plants if they display signs like leaves that suddenly change color or wilt/droop. This sort of sickness is one of the most aggravating for Lemon button fern owners.

Why are my Lemon button fern leaves turning yellow?

This is probably the most common problem in the gardening world, yellowing leaves. There are 2 main reasons for this phenomenon, overwatering, or a lack of nutrients.

Reduce your watering frequency when you fear your plants are being overwatered, and follow these steps to determine whether they may be lacking in nutrients:

Each deficiency produces a different yellowing on the Nephrolepis cordifolia ‘Duffii’ in question, here’s how to spot them:

  • Magnesium deficiency starts as yellow patches between leaf veins on older leaves. Veins stay green as yellow moves from the leaf center out. Leaf edges turn yellow last.
  • Another indicator of iron deficiency is yellowing between leaf veins, but young leaves on plant tops and branch tips are first affected.
  • Sulfur shortage first affects the youngest leaves, turning them entirely yellow.
  • Leaf edges turning bright yellow but inside leaf remaining green are signs of potassium insufficiency. The symptoms first appear on older leaves, and the leaf edges quickly become dark.
  • Nitrogen deficiency shows up as a general yellowing. Older, inner leaves turn yellow first. As it progresses, yellowing moves outward, eventually reaching young leaves, too.

Our Solution

You only need to act in accordance with the symptoms listed above. You can address a potassium or nitrogen deficiency by buying a particular soil, and a gardening store consultant will be able to advise you on how to do that. Furthermore, you can also limit how frequently you water your plants.

Is my Lemon button fern sunburned?

It is quite easy to find out if your Lemon button fern (Nephrolepis cordifolia ‘Duffii’) has been burned by the sun. Just like on us, your plant will change color in this case, it will start to turn yellow or white.


As we saw above, if your Lemon button fern receives too much water or not enough light, the leaves may also change color.

However, there is a way to tell if it is sunburn; look at the bottom of the yellow leaves, the ones that have a shaded area closer to the root, if this area stays greener, it is probably sunburned, not something else.

Why are my Lemon button fern leaves turning brown?

Most of the time, leaves of a Lemon button fern that turn brown is a sign that your plant has been sunburned, it has probably been exposed to too much direct sunlight. Don’t panic, your plant probably won’t die from this, but its growth will take a hit.

Should I leave my Nephrolepis cordifolia ‘Duffii’ in direct sunlight?

No! Don’t leave your Nephrolepis cordifolia ‘Duffii’ (or Lemon button fern) in the sun if it displays the symptoms mentioned above; that’s why it’s in such a bad situation.

Our Solution

As explained in the paragraph above, the solution is simple, just place your Lemon button fern in a place where the light does not reach it directly, in this way and with a correct watering, your plant should resume its life rather quickly.

Why are my Nephrolepis cordifolia ‘Duffii’ leaves drooping or wilting ?

This typically occurs when your Nephrolepis cordifolia ‘Duffii’ gets dehydrated. Large plants are more at risk since they naturally require more water than smaller plants.


You may quickly determine if your Nephrolepis cordifolia ‘Duffii’ plant needs water by under-weighing its pot; if it seems light, the soil and roots are probably fairly dry and require water.

Our Solution

If the soil in your plant’s pot is completely dry, you will need to start by moistening it so that the roots will also benefit from the water. A common mistake is to drown the Lemon button fern right after a dry period thinking that it needs a lot of water.

This is true, but the easiest way to end it is to give too much water at once. Instead, you should water the soil properly, returning to a peaceful watering rhythm.

Caring Tips for Nephrolepis cordifolia ‘Duffii’

Water Occasionally

Water is essential to the survival of your plant, however, it is important to balance the rate of watering. As we explained above, overwatering could have fatal consequences for your Nephrolepis cordifolia ‘Duffii’.

Touching the soil will let you know whether your plant needs water or not; if it still feels damp, it’s generally best to wait a few more days.

Always keep temperatures stable

It’s also a good idea to keep your Nephrolepis cordifolia ‘Duffii’ at a constant temperature, especially if it’s kept indoors. In general, at GreenShack, we suggest booking a temperature between 65 and 85 degrees F. Of course, keep your Nephrolepis cordifolia ‘Duffii’ away from radiators, air conditioners, and other sources of hot or cold air.

Keep your Lemon button fern Dust-Free

This one relates to indoor plants. Just like your furniture, dust collects on the leaves of your indoor plants. The issue is that this can block the photosynthesis process from starting, which would cause the plants to gradually lose their color.

For your Lemon button fern, this would be a true descent into hell, and it would also appease the pests.

Take a microfiber cloth and gently massage the plant’s leaves to get rid of the dust. Use a damp cloth to make dust removal easier, but avoid using corrosive materials like rubbing alcohol!

Keep drainage in mind

If you have a tendency to overwater, you need to keep an eye on your drainage, we advise you to opt for a pot with drainage holes if it is not already the case and a saucer.

In the meantime, if you don’t have holes in your pots, you can add volcanic rocks (or any rocks with holes) at the bottom of your pot, this way it will create a channel so that the water doesn’t stay in your skin too much (to avoid that roots start to rot!)