7 Signs an Asparagus Fern Is Overwatered

Asparagus ferns are lush green tropicals loved by indoor and outdoor growers alike. Since they’re native to tropical climates, they get thirsty more often and need to be watered more frequently than the average plant. However, you can go overboard and give the plant too much water. 

Signs an asparagus fern is overwatered include:

  1. Black, soggy roots
  2. Unpleasant smelling soil
  3. The presence of fungus gnats
  4. Yellowing foliage
  5. Falling needles
  6. Drooping leaves
  7. The soil never dries out

In the rest of this article, I will discuss how overwatering causes some of these symptoms. I’ll also tell you how to control and reverse the damage caused by overwatering. Here are seven signs of an overwatered asparagus fern.

1. Black, Soggy Roots

Like all plants, asparagus ferns have a web of delicate roots under the soil. These roots need oxygen to survive and maintain normal function. If they are unable to acquire oxygen, they suffocate and die. 

This is why it’s crucial for the soil or potting mix of your choice to be porous and aerated. It’s also why compact, dense soil is unfavorable for plant growth—the oxygen within such soil tends to be limited. 

Overwatering is as deadly because it has a similar effect. Waterlogged soils cut off much-needed access to oxygen for your plant’s roots. 

If the soil remains completely saturated for too long, the roots inside will die off, leaving the plant incapable of supplying itself with the vital nutrients it needs to continue to live. 

As the roots die, they become soggy because of all the excess water. And, like all organic matter in moist environments, they begin to rot. The rotting causes their color to darken to an orange-brown. Eventually, the roots will turn black. 

It’s worth mentioning that root rot can also be caused by the growth of harmful fungi in the soil. Note that fungi love moist conditions, so it’s overwatering that leads to fungal growth in the first place. 

If you suspect that your asparagus fern suffers from overwatering, the best way to confirm your theory is to dig up the plant from its potting media and examine the roots. 

Unfortunately, root rot is often an irreversible condition. Once more than 30% of the roots have decayed, the plant cannot be saved. 

If you notice any rotting roots and want to give your asparagus fern a chance at survival, you should take the following steps:

  1. Remove the plant from the saturated soil.
  2. Cut off all its damaged roots with sterile pruning shears.
  3. Rinse the roots with running distilled water.
  4. Dry the roots for an hour on top of a clean towel.
  5. Transplant your asparagus fern into a fresh and sterile potting mix.
  6. Water the plant deeply.

After that, you can only hope for the best. If the plant still has some healthy roots, it may well survive and gradually recover. 

2. Unpleasant Smelling Soil

It’s understandable not to want to uproot a plant to check for overwatering, especially if the present symptoms aren’t severe and the plant is otherwise healthy. 

Fortunately, there are plenty of ways to identify overwatering by observing the topsoil. 

Even before you observe any visual changes in your plant, its smell may alert you to the beginnings of root rot. Root rot is often accompanied by a nasty, swampy odor. However, you may not notice this smell on your average day because it stays concentrated around the decaying roots. 

Unfortunately, if you do notice the smell of root rot, the damage has already been done. 

The root health below the soil is likely compromised. At this point, I recommend digging up the plant for a visual inspection before proceeding further. 

If you do see black roots, you should cut them off and transplant your asparagus fern, as we discussed earlier. 

When dealing with smelly roots, you should use a sanitary tool to cut them off. Scissors and knives will do the job perfectly fine, but it’s essential you sanitize the instrument before, after, and maybe even during the cutting process to prevent the spread of any stray fungi. 

The nasty smell should subside once you dispose of the decaying roots. 

3. The Presence of Fungus Gnats

Fungus gnats are a widespread indoor pest, although they sometimes attack outdoor plants as well.

While gnats may settle on a plant at random, they tend to favor overwatered plants. So, if you see fungus gnats on a plant, there’s a good chance it’s been overwatered. 

As mentioned earlier, overwatered soils are much more conducive to fungal growth. It’s this fungal growth that attracts fungus gnats. The larvae of the tiny critters feed on fungi in the soil as they grow. 

While fungus gnats aren’t dangerous to humans (they don’t bite or transmit disease), they threaten the health of your asparagus fern. While they primarily feed on fungi, they also consume plant roots. 

This is all the more dangerous for overwatered plants, as they have damaged roots, to begin with. 

Fungus gnats can also spread from plant to plant. An infestation, if inadequately handled, can spread to your entire indoor collection. 

Fortunately, there’s an easy way to deal with gnats—you can make your own homemade pesticide spray using common household ingredients such as dish soap and vinegar.

4. Yellowing Foliage

Asparagus ferns are usually a beautiful green when healthy. However, when overwatered, they lose their green color and start turning yellow. 

The foliage will first turn yellow at the tips, from where the yellowing will gradually extend to the rest of the plant. In severe and prolonged cases of overwatering, most of the foliage can turn a pale yellow. 

The good news is yellowing foliage is one of the first symptoms of overwatering you’ll see, which is why you need to take remedial action as soon as you see it so that your asparagus fern does not end up with permanent damage. 

If you catch the condition early enough, you can likely get away with it by simply readjusting your watering routine and being more conservative with the amount of water you give your asparagus fern moving forward.

Admittedly, yellow foliage can be caused by conditions other than overwatering. Limited exposure to sunlight, for example, can cause leaves to turn yellow. Underwatering and lack of nutrients can also cause yellow leaves, although this is less common. 

Regardless, if your asparagus fern’s leaves start to turn yellow, you know that something is off. Check for additional symptoms to understand better what’s causing it. 

5. Falling Needles

Asparagus ferns are notorious for this problem. Their thin, needle-like foliage drops off in droves, creating a mess indoors. 

Again, multiple conditions can be responsible for this dropping of needles, but they all point to environmental stress. 

That said, one of the most common causes of needles dropping off of asparagus ferns would be overwatering. Another common cause is a lack of humidity

When needle fall-off is caused by overwatering, it’s often preceded and accompanied by yellowing foliage. If your asparagus fern exhibits both of these symptoms simultaneously, overwatering-induced stress is the likely cause. 

A few lone needles here and there are not unusual.

6. Drooping Leaves

You’ll probably see the leaves of your asparagus fern droop and wilt when they need more water. 

In nature, leaves droop when a plant craves water. Drooped leaves reduce the overall surface area of the plant exposed to sunlight. In this way, the plant keeps its body cooler and reduces water loss from evaporation. 

However, too much water can also cause leaves to droop. Interestingly, in this case, too, the plant is craving water. But why would a plant sitting in abundant water need more of it?

Well, recall what overwatering does to roots. It restricts their exposure to oxygen, which leads to suffocation and death. 

Dead roots, of course, do not transfer nutrients and water up the plant. So even though your asparagus fern is surrounded by water, it doesn’t get to access sufficient quantities of it. 

But drooping leaves can be caused by both underwatering and overwatering, so how do you tell which is the root cause of your plant’s drooping leaves?

Again, the solution is to examine the soil. Just make sure to dig more than 2 inches (5 cm) deep because surface-level soil dries out first and does not accurately reflect the true saturation level below the soil surface. 

Another way to discover the source of drooping leaves is to water the plant. If the drooping leaves don’t perk up within a few hours after watering, overwatering is the more likely scenario. 

7. The Soil Never Dries Out

The chances of you overwatering your asparagus fern increase dramatically if your soil has poor drainage. 

Water drainage is dependent on the quality of your potting mix. It’s advisable to spend a few bucks extra to get a high-quality, well-draining potting mix so you don’t have to run into water retention problems down the line. 

Your pots and containers should have drainage holes as well. While it is possible to use a container without a drainage hole using compensatory strategies, it’s not worth the hassle and increased risk.

If you notice that your soil takes weeks to dry out or that it never dries out completely, your soil quality may be the problem. You’ll run into overwatering-induced problems sooner rather than later.

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of TheGrowingLeaf.com, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

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