Plants are mainly used indoors for freshening purposes, so when your plant starts smelling fishy, you start questioning your decision to buy it in the first place.
Boston ferns originally have a mild scent that compliments lavender well. However, you barely notice it outside, and indoors, it may appear if the humidity is high.
If your Boston ferns are smelling bad, it’s the soil causing it. It’s because of either root rot, water logging, a non-porous pot, or other reasons.
Here, we’ll explain why Boston ferns smell and what you can do to fix it.
Why Does My Boston Fern Smell?
To determine the reason for your fern’s fishy smell, you first need to know the real culprit: the soil.
Plants don’t give off bad smells, even when there’s something wrong with them. So, the smell belongs to the soil.
Your Boston fern’s soil likely smells bad because it’s compacted, waterlogged, lacking oxygen, or infested with pests. You’re likely overwatering the plant, using the wrong type of soil, or using a non-draining pot. Here are all the possible reasons in detail.
1 – Bad Soil
If you recently bought your Boston fern and it’s already starting to produce a bad smell, there’s a high chance you put it in the wrong soil.
Boston ferns need well-draining soil to grow correctly and thrive. If the soil is compacted, it’ll keep collecting the water, eventually leading to root rot.
So before you blame the bad smell on the plant or the surrounding conditions, first make sure you’re using the right soil type. Compacted or heavy soil will cause the leaves to curl, droop, and turn yellow.
2 – Overwatering
Overwatering is the reason for almost all soil issues. You may think some extra water will do the plant no harm, but it’s doing more harm than you think.
When the water is too much for the soil, it’ll stop draining, even if the soil is well-draining and the pot has holes on the bottom.
When the water collects in the soil, it closes the air pockets that are supposed to circulate the air. So, the soil becomes compacted, and fungus begins to grow as a result of the waterlogging.
In the end, you’ll find a bad smell emitting from the soil, and it won’t go away until you replace it with a new one and cut off the affected roots.
3 – No Drainage Holes
You got the soil right, you give the plant enough water, yet the smell is still there. Why is that?
There’s a high chance your pot doesn’t have drainage holes in the bottom. Pots for flowers and indoor plants should have drainage holes to let the excess water pass through.
If your pot doesn’t have those, the water will collect in the bottom, leading to soggy soil and eventually rotten roots.
4 – No Ventilation
Boston ferns need to be placed in a well-ventilated room so the humidity doesn’t suffocate their soil. The bad odor emitting from your plant can very well be because of the lack of ventilation.
When the air stays humid around the fern, the evaporation rate decreases. As a result, the soil stays wet without drying out. You probably now know that wet soil is a recipe for rotten roots and a foul smell.
Always make sure the room with the Boston ferns is well-ventilated and that there aren’t many plants in the room. If you cram many pots in one room, the airflow will be hindered.
5 – A Full Saucer
If you have a saucer underneath your flower pot, don’t forget to empty it once it gets full. These saucers aim at letting the water out of the pot so it doesn’t leak into the ground or the shelf you’re putting the plant on.
Once the saucer gets full of water, it should be emptied for two reasons. For one, letting it be full can cause the water to leak. Additionally, the water will keep seeping back into the soil through the drainage holes, which may cause pathogens to grow.
Remember that bacteria and moisture are best friends, so always try to keep excess moisture away from your plant.
If you don’t want to bother with emptying the saucer every now and then, you can take an easier route and use a pebble tray. The pebbles will absorb the water without letting it collect, and you won’t have to empty the tray as frequently.
How to Know There’s Something Wrong With Your Boston Fern
Aside from the foul odor, there are some telltale signs to let you know that something’s wrong with your fern. As we explained earlier, the bad smell is likely due to root rot or waterlogging. Chances are, these conditions won’t only cause a scent, but they’ll appear on the plant’s leaves and stems as well.
Here are signs that your ferns are infected by bacteria or rot.
Slow Growth
Boston ferns are already slow growers, so when their growth gets even slower than usual, you can be sure there’s something wrong with the plant.
Try to monitor your plant and see how often it grows. To do that, you can either take measurements or take a picture of the plant.
Then, after a month, re-measure it or take another picture and compare. If the plant isn’t growing at all, start checking the roots for rot or the leaves for any signs of lack of nutrients.
Tiny White Worms
Do you know those tiny white worms that appear on top of the soil? These aren’t actually worms; they’re fungus gnat larvae. Fungus gnats are usually attracted to house plants, so you may find them around your fern if it’s inside the house.
These larvae may be harmless when they’re only a few, but if the infestation is severe enough, they’ll be feeding on all of the nutrients in the soil. As a result, the ferns will find nothing to feed on, and the roots will start rotting.
If you see tiny white worms on the soil’s surface, start looking around for signs of fungus gnats. If there’s an infestation, you’ll need to start taking some steps to get rid of it.
Yellow Leaves
While some plants regularly grow yellow leaves, Boston ferns don’t. So, when the leaves are yellow, that means something is hindering their growth. You may also notice the leaves discoloring to a different color.
If the leaves are turning yellow, black, or brown around the edges, you can be sure the soil is too soggy for them. You’ll also see other signs on their physical appearance, like curling or wilting.
If the leaves are getting soft, the rot has probably been there for a while. It may be too late to fix it then.
Final Thoughts
So, do Boston ferns smell?
No, they shouldn’t have a smell other than the earthy odor of the soil. If your fern is emitting a bad odor, there’s a high chance its soil is water-logged, or its roots are rotten. You may notice other symptoms as well, such as yellowing or curling leaves.
If that’s the case, first check the soil. If it needs replacement, put the plant in a new larger pot with drainage holes on the bottom.

Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.