Overwatering or poor drainage are the most likely reasons behind your Asparagus Fern turning yellow. Yellow leaves may also result from low humidity, improper lighting, pest infestation, or nutrient deficiency.
This guide will help you get to the bottom of the problem and advise you on the best route to get your plant back to good health.
Asparagus ferns are hardy, so don’t fret if they show signs of distress. With a little care and change in routine, they can soon be on the road to recovery.
I add these plants into any space that needs a splash of bright green and encourage the growth of their glossy red fruits to encourage visits from birds.
Related to both asparagus and lilies, the asparagus fern is not a true fern. However, its frilly fronds do give it the appearance of one.
It’s a plant that is easy to care for and can be found in gardens, homes, offices, waiting rooms, and businesses across the country.
The plant can boast vivid bright green foliage that makes it especially attractive. However, you may see this fade to yellow if the plant's requirements are not met.
Let’s take a further look at what might be causing your asparagus fern to falter.
Soaking the roots of the asparagus fern prevents it from getting enough oxygen and this means the plant suffers and the fronds begin to turn yellow. The way to prevent this is good drainage and avoiding overwatering.
Although this plant does need a lot of watering, many people accidentally overcompensate and add too much water. This problem is compounded by poor drainage.
Water asparagus ferns once or twice a week, ensuring that the topsoil is completely dry before watering again.
To make sure your asparagus fern has good drainage, invest in a good pot. Make sure the pot has holes for the water to run through.
Larger pots allow better drainage, and natural materials, such as terracotta or clay, are porous which helps water leave the soil.
To further improve drainage, a mix of 60% peat, 30% perlite, and 10% compost is the best mix for asparagus ferns. If you are noticing that it takes a long time for your asparagus fern pot to drain, repot the plant in this mixture.
If you catch overwatering early, and follow these steps to properly water and drain the plant then it will recover easily. If it takes longer the plant may develop root rot, which compounds the issue.
With root rot, you will see brown or black mushy roots. Cut these away with sterile pruners before repotting the plant.
Asparagus ferns can suffer from both too much and too little light. In nature, you’ll often find it on shady roadsides or woodlands. And, although it needs low levels of direct light, it is still possible for it to receive insufficient amounts which will cause the plant to become sparse and yellow.
You will see guidelines to put an asparagus fern in ‘bright, indirect light, but this can lead many to put it in lower lighting levels than it actually needs.
Have a look at what kind of shadow the light shining on the plant casts by holding a hand near the floor or wall nearby. A fuzzy outline on an otherwise clear shadow is the perfect amount of light.
If instead, it is completely fuzzy, move the plant to a place with sufficient light and it should soon recover. Keep an eye on the location as the seasons change.
Do not keep the plant anywhere where it will receive more than 1-2 hours of direct sunlight either, as this is too much and it will damage the plant. Keep asparagus ferns away from windows, especially in warmer months.
The most common pests to infest asparagus ferns are mealybugs, spider mites, and pests. They are sap suckers that weaken the plant's health and cause it to turn yellow.
They are tiny, so spotting them can be hard. Shake the plant over a blank piece of paper and look for any small black spots that appear to figure out if your plant has an infestation.
If they are there, use a sharp jet of water to clear them from the plant and then treat the plant weekly with insecticidal oil to prevent their return.
A balanced, water-soluble fertilizer added to an asparagus fern every 3-4 weeks should be plentiful. If you have added fertilizer too frequently, a build-up of salts will prevent your plants from getting the nutrients it needs.
You will see these crystalized salts on the soil and roots of the plant. Rinse them off and repot the asparagus fern to return them to full health.
On the other hand, if you haven’t fertilized your asparagus fern in a long time, and nothing else seems to be causing yellow leaves, begin to add this care to its routine. In time, you will soon see an improvement in its health.
Frequently Asked Questions
Have more questions about these popular plants? Here are a few of the most common ones answered.
Q: When do asparagus ferns bloom?
A: Asparagus ferns bloom, producing tiny white flowers. This is usually in summer, but can be any time from spring to fall.
Q: What temperature should I keep asparagus ferns at?
A: Asparagus ferns need a minimum temperature of 55°F (13°C).
Q: Can I grow asparagus ferns outside in my region?
A: If you live in hardiness zone 9 or warmer, you can grow these plants outdoors.
Asparagus Fern Turning Yellow – Conclusion
Taking care of your asparagus plant should be easy once you ensure it is in well-draining soil and don't overwater it. If you are sure that this isn’t the problem, check through the above list of these other common issues until you find the one that’s bothering your plant.
Once corrected, it won’t take long for this sturdy plant to return to luscious green once again.
Have questions about other plant leaves turning yellow? Check out our guide on Sunflower or Rose of Sharon.