The bird’s nest fern is one of the many unique houseplants that is easy and low-maintenance to grow. However, it can be vulnerable to fungal issues that can be challenging to treat, one of which is crown rot disease.
Overwatering is the leading cause of crown rot, but other factors like a lack of sunlight or poor soil drainage can also exacerbate the issue.
We will discuss below exactly what crown rot is in bird’s nest ferns, and how to tackle this dreadful plant disease.
What is crown rot disease?
Crown rot is described as a soft decay found at the center of a plant. It is mainly caused by soil-borne fungal pathogens which attack the plant’s lower branches that are near to the soil. Any plant can get crown rot disease, be it a tree, an ornamental plant, or even a vegetable crop. Unfortunately, there is no effective cure for crown rot once the symptoms are present.
Is my bird’s nest fern dying?
There are many possible reasons your ferns might die, and one of these is fungal diseases such as crown rot.
The most obvious sign of crown rot in a bird’s nest fern is the browning of the fronds and crown. At first, you might think that the plant is simply struggling with drought and give it more water – until it is too late. Soon, the dead tissue will start spreading to the branches and then throughout the plant. By this time, there is little you can do to save your bird’s nest fern – you will likely have to throw it away and start over with a new plant.
What causes bird’s nest fern crown rot?
Crown rot disease is one of the many consequences of overwatering. So, before you pamper your plants, put down your watering can and listen up!
Bird’s nest ferns typically need watering once every week or two, although this also depends on current weather conditions. The golden rule is to allow the top layer of soil to dry out completely in between waterings. Give the plant more water during the hot, dry season, and reduce your watering during the colder months. At all costs, avoid giving it more water than it needs!
If you keep overwatering your plants, the soil will become saturated and create an ideal growing environment for fungal spores. Thus, this waterlogged state is what you need to avoid to prevent fungal-related diseases like crown rot.
Aside from crown rot disease, an overwatered bird’s nest fern also becomes vulnerable to other issues like pest infestation, root damage, leaf discoloration and, eventually, death.
2. Frequent overhead irrigation
Many gardeners argue that watering from above is not advisable for most plants, while others believe that this is just a myth. There might be mixed opinions when it comes to the correct watering technique, but the fact remains – the longer you keep your plants’ foliage wet, the more chance of promoting fungal and bacterial growth.
For this reason, overhead watering is generally discouraged, especially if you water your plants late in the afternoon, since this can leave the foliage wet throughout the evening. As mentioned previously, fungal spores thrive in damp environments, so overhead watering, especially at the wrong time, can play a role in the development of crown rot.
The most recommended watering technique is to water your plants directly at the roots. Unlike overhead watering, direct watering of the soil reduces water waste and prevents the leaves from getting wet. But again, timing is key. If you water your plants in the late afternoon when the day is cooling off, you might increase the risk of root rot.
3. Using soil with poor drainage
Compacted soil tends to hold more water, so be careful when choosing a soil type for your bird’s nest fern. Even if you are not overwatering, using a poorly-draining pot or soil can still result in root rot and crown rot diseases.
To avoid overly damp soil, we recommend using a potting mix for orchids that has a high peat content. This will keep the soil moist, but not waterlogged.
Remember that an underwatered bird’s nest fern is easier to save than an overwatered one. Make sure that the soil is loose and well-draining, and avoid using pots or containers without drainage holes!
4. Lack of light
Did you know that a lack of sunlight can also put your plants at risk of fungal diseases?
We are all probably aware of the sun’s important role in the process of photosynthesis. If your plant is light-deprived, it will eventually show signs of distress, the most obvious usually being yellowing leaves.
But apart from this issue, a lack of exposure to sunlight combined with overly moist soil can further encourage fungal spores to thrive. Without light, it will take longer for the soil to dry, thus promoting the same symptoms as overwatering.
For optimal growth, therefore, it is crucial to place your bird’s nest fern in an area that gets filtered sunlight. Note that too much bright light can also be bad for it, since it can wrinkle or burn the foliage.
Watch out for mold as well – this is a sure sign that your bird’s nest fern is struggling with overwatering and a lack of light.
Can you save a bird’s nest fern with crown rot?
Unfortunately, crown rot disease in bird’s nest ferns can be very challenging to treat, especially when the disease has become severe. In most cases, the affected plant will die prematurely, which is why plants with crown rot are often thrown away.
Your best weapon against crown rot disease is to prevent it from happening in the first place. As mentioned already, avoid overwatering your fern at all costs. Make it a habit to check the soil regularly so that you know when your plant needs hydration. Giving the soil time to dry out between waterings will help prevent soil-borne pathogens from ravaging your fern.
Although fungicides are available, they are often only effective when used as a preventative measure, or if the disease is caught early enough. Once the fungus has started to spread on the crown, the best you can do is as follows:
- Discard the infected plant, and do not use it in your compost heap!
- If it was planted in the ground, replace the soil up to about six or eight inches deep. You can also solarize the infected soil by covering it with clear plastic and allowing it to dry under the sun for three months.
- Apply fungicides, like mancozeb or thiophanate methyl. If you prefer an organic approach, you can skip this step and just follow the ones mentioned previously.
- Do not be afraid to try all over again, keeping in mind the lessons you have learned from your previous plant.
Tips to prevent bird’s nest fern crown rot
Crown rot disease can be really tough to treat. Thankfully, though, with proper care, the disease can be completely prevented, instead. You will not have to endure all the hassle and heartache of replacing an infected bird’s nest fern if you just follow these steps:
1. Pick a healthy variety
Bird’s nest fern only comes in a few varieties, but you can pick a healthy one depending on your preferences and the location where you intend it to grow. For example, the Osaka variety can be a great ornamental plant, both in your indoor living space or your outdoor garden, since it can tolerate various lighting conditions.
2. Use a well-draining soil mix
Well-draining soil is a basic growing requirement for all plants – not just bird’s nest ferns – because it allows their roots to breathe. A peat-based potting mix rich in organic matter is by far the best growing medium for a healthy bird’s nest fern.
3. Give plenty of filtered light
Most bird’s nest fern varieties thrive in filtered sunlight. If you are growing yours indoors, the ideal location should be near a north- or east-facing window.
4. Use appropriate watering techniques
While watering your plants from above might help clean their dusty leaves every now and then, this technique is not always recommended. The leaves must be kept dry as much as possible to discourage fungal diseases. Make sure to water your fern directly into the soil – not only to help keep the pathogens away, but also to waste less water.
5. Do not overwater
Overwatering is the easiest way to kill a plant! If you want to keep your fern healthy and thriving for years to come, make sure to give it just enough water – not more or less. Use a soil moisture meter to help you determine the best time to water your plants.
6. Do not over-fertilize
Feeding your plants more does not equate to better or faster growth. Bird’s nest ferns should only be given a half-strength dilution of your chosen fertilizer, and only during the growing season. Do not apply fertilizer during the cold months.
7. Maintain a warm, humid environment
Bird’s nest ferns are native to tropical regions, so they grow better in warmer temperatures – preferably between 70 and 90 degrees Fahrenheit. Note that their native habitat is also humid, so although they might tolerate lower humidity levels, they will thrive in an area with 30 to 50 percent humidity.
Crown rot is a serious fungal disease with no known cure, and saving your dying bird’s nest fern is likely to be a futile effort! The only way to win the battle against this soil-borne disease is to implement preventative measures and give your plant the best possible care to keep the pathogens at bay.
Image: istockphoto.com / SangSanit