Why Is My Asparagus Fern Turning Yellow And What To Do?

With delicately fuzzy foliage extending in dense plumes, the Asparagus fern stays trouble-free, interesting, and beautiful at most times and becoming more popular these days. But you may sometimes have to look for the answer to why is my asparagus fern turning yellow and some ways to fix this issue. Overwatering and insufficient light are the most common causes of this. We will also discuss excessive light, fertilizer problems, underwatering, and pest issues that may cause the asparagus fern to turn yellow.

What are the causes of the asparagus fern turning yellow?

If you are pondering over why my asparagus fern is turning yellow, then we are here to help you and answer your queries. The common reasons for this problem with an asparagus fern are:

• Issues with watering
• Not the right potting mix
• Low humidity levels
• Improper lighting
• Low temperatures
• Improper fertilizing
• Pest infestation
• Transplant shock

 You should first find out the cause of the problem troubling your asparagus fern and the answer to why is my asparagus fern turning yellow, then you can find out the right way to solve the issue and make your asparagus fern grow healthily again.

1. Issues with watering

AN asparagus fern can act quite well even in drought time because of its tuberous roots that store water when it is available excessively. But the plants’ roots can rot because of overwatering. This is because soggy soil doesn’t allow the roots to intake oxygen for their survival. This may leave me wondering the question: why is my asparagus fern turning yellow?

If the soil of an asparagus fern stays dry for a long time, then it can also cause the plant to turn yellow. You will first see the leaves becoming yellow, and then they will become brown and crispy before finally falling off. 

Solutions:

• Cease watering till you feel the soil has dried out completely
• If the soil doesn’t dry out properly, then put the plant in direct sunlight for 24 hours
• It is also good to take the plant out from its pot and put in on a newspaper to dry over for a day or two
• If the soil smells bad, then remove the affected roots by using sterile pruners and try to repot the plant with a potting mix containing 30% perlite, 60% peat, and 10% compost
• It is better to plant asparagus fern in a suitable pot as a larger pot can make it difficult for the soil to dry out completely
• If your asparagus fern is underwatered, then water the plant thoroughly till you see excess water draining out from the drainage holes

2. Not the right potting mix

Asparagus ferns grow best in slightly acidic (6.5-6.8 pH) and well-draining soil with a lot of drainage holes in the pot. If planted in poorly drained soil, your Asparagus fern is more prone to be attacked by bacterial and fungal diseases. The soil should not be compact as it has lesser air spaces in it which clock the oxygen flow inside the roots and prevent nutrient intake. 

The problems caused by the wrong type of soil and potting mix can make you arrive at the question: why is my asparagus fern turning yellow?

Solution:

• Use a stick or trowel to loosen up the soil, but do it carefully to not damage the root system
• To increase the airflow and drainage capacity of the potting mix, add stones or pebbles at the bottom of the soil
• If there are no drainage holes in the pot, then you can drill them yourself before planting the asparagus fern
• Add nitrogen fertilizer to the soil to make it nutrient-rich and grow green feathery leaves on the fern
• If the soil is not good, then try using a new potting mix with peat, perlite, and compost in the ratio 6:3:1
• The best pots to use are made of clay or terracotta and they should have a lot of drainage holes for drainage and be strong enough to hold the entire root system

3. Low humidity levels

The best humidity levels for asparagus fern are moderate, between 60 and 80%. If the humidity level is above the optimum, then it will stunt the overall growth of the fern, causing the leaves to curl and fall off. 

If the humidity around the plant is less than the optimum, it will make the asparagus fern leaves transpire and lose moisture vigorously, resulting in yellow leaves with brown edges.

Solutions:

• Mist the plant regularly using a spray bottle with fine spray
• Try to keep your asparagus plant over water-filled gravel
• You can also use the pebble tray method to allow normal evaporation. For this, fill a sauce with pebbles, add water to it, and place the plant in this tray
• Place the plant where there is high humidity, such as in the bathroom or the kitchen
• Install a humidifier near the plant to boost the humidity levels at any time

4. Improper lighting

If you expose your asparagus fern to too much direct sunlight or it lacks adequate light, it can leave you thinking over the question: why is my asparagus fern turning yellow? Asparagus ferns grow best in places that receive 4-6 hours of bright but indirect light and have moderately warm temperatures. Leaves start to turn crispy and have yellow or brown edges if the intensity of light exceeds the optimum level. On the other hand, a low intensity of light or no light at all can make the leaves discolored and the plant has leggy growth.

Solutions:

• Put the plant in a northeast-facing window where light is balanced
• To boost recovery, the plant should receive 1-2 hours of morning sunlight daily
• Use drapes or curtains on the windows if there is too much sunlight or place the plant one meter off the window
• To provide a good balance of light, put the fern under artificial grow lights for 10-12 hours every dayWhen planting asparagus fern outdoors, hang in the shade of a tree or on a patio to avoid coming across the question: why is my asparagus fern turning yellow

5. Low temperatures

Asparagus fern grows best in warm temperatures between 65 and 80 degrees Fahrenheit, and cannot tolerate temperatures below 55 degrees Fahrenheit.

If the plant is grown in places where temperature varies, such as near heating vents or any radiation, then this can affect the rate of leaf growth and lead to yellow leaves.

Solutions:

• Carry the plant indoors during the harsh winter outside
• Place the plant away from any ventilation and air conditioning vents and where they receive bright indirect sunlight
• To protect the asparagus fern in the winter, use heating pads and a frost blanket
• To store the warmth and prevent heat loss, mulch the topsoil using sawdust or straw
• Another way to protect the plant from cold is to create a greenhouse effect using transparent plastic

6. Improper fertilizing

Asparagus fern has low fertilizer needs and grows best in soil rich with organic matter. But you should try adding a bit of nutrient from time to time. Under-fertilization and over-fertilization can both make you come across the question why is my asparagus fern turning yellow. So, balance the plant’s needs by providing it with fertilizer.

Under-fertilization

This happens if the plant lacks a good supply of nourishment for a long time and it causes the asparagus fern to limp and droop, resulting in yellow leaves.

Solution:

• It is good to moisten the soil before you apply a fertilizer unless you use a liquid fertilizer
• A good blend of fertilizer for asparagus fern is one that contains nitrogen, phosphorous, and potassium in equal parts
• Pause the fertilizer supply in the winter but continue it during the growing season with one application each month

Over-fertilization

Over-fertilizing not just causes yellowing symptoms, but it also makes the leaves develop brown tips.

Solutions:

• Take a long gap for some months before you fertilize the plant again
• Water the plant thoroughly to drain the fertilizer out of its roots
• Remove any solid forms of fertilizer from the soil, but retain almost ¼ of the soil
• Cut off the wilted and yellow leaves

7. Pest infestation

There are three common pests that are likely to infest asparagus fern and give you the possible answer to why is my asparagus fern turning yellow.

Type of pest	How they look like	Signs of infestation
Mealy bugs	Pale and small having waxy filaments	Leaves turning yellow and falling off
Houseplant scale	Similar in appearance to fish scales stuck to plants	Deformation of leaves, pale leaves having brown pockmarks
Spider mites	Tiny in sizeWhen infestation is heavier, there is also a web	Spotty surface and discolored leaves

By making the plant weak, these pests extract good nutrients and hydration from the plant, thus resulting in yellowing of the plant.

Solutions:

• Wipe alcohol on the surface of leaves by using a cotton swab
• Cut off the parts of leaves that are heavily infected
• Use insecticidal soaps to spray on the plant
• Use your own insecticidal soap for spray by mixing one tablespoon of liquid baby soap in 1 liter of water
• Separate the healthy plants from the infested ones
• Another good option for an insecticidal spray is using neem oil