Why Are My Wisteria Leaves Turning Yellow? (What to Do?)

While the leaves of your plant turning yellow is perfectly normal during some periods of the year, it could also mean that something is wrong with your plant that requires immediate attention.

The wisteria plant is no exception to the rule, which is why it’s a good idea to ensure that nothing is wrong with your plant if you notice that the leaves of your wisteria are turning yellow.

As there are a few different problems that can cause the leaves of your wisteria to turn yellow, the best course of action is to learn these problems, look for other symptoms that come with these problems, and apply the necessary care.

So, why could be the leaves of your wisteria turning yellow aside from seasonality?

Underwatering, overwatering, iron deficiency in the soil, poor drainage, viruses, fungal diseases, and pests such as scales and aphids can all cause the leaves of your wisteria to turn yellow.

As all of these problems come with unique symptoms of their own, finding which one is giving your plant trouble comes down to careful inspection.

Next up, we will be going into detail about each of these issues and their unique symptoms. By comparing these symptoms to the ones your wisteria is showing, you can quickly pinpoint the problem.

Why Do Wisteria Leaves Turn Yellow?

As the leaves of your wisteria could be going yellow for numerous reasons, learning about all of these reasons in detail will be extremely helpful to find out what the problem really is.

Underwatering

Underwatering is one of the first things that come to mind whenever there are yellow leaves, as your wisteria not getting enough nutrition can easily cause its leaves to become yellow.

If your plant is suffering from underwatering, you should also be observing the symptoms listed below.

  • Wilting – Wilting is perhaps the most common symptom of an underwatered wisteria as your plant loses rigidity if it can’t get enough nutrients.
  • Dry soil – If the soil located an inch or two below the surface is dry, it’s a good sign that your wisteria isn’t getting enough water.
  • Problems with growth – It’s common knowledge that plants can’t grow without water. If you’re observing that your wisteria isn’t growing as quickly as it should, underwatering may be the issue.

Overwatering

Just like underwatering, overwatering can also easily cause the leaves of your wisteria to go yellow and is one of the most common reasons behind plant leaves going yellow.

Here are the symptoms you would observe if your wisteria is suffering from overwatering.

  • Wilting – Just like underwatering, overwatering can also cause wilting. If you’re observing wilting, it’s a good idea to check the moisture status of the soil for further information.
  • Wet soil – If the soil located an inch or two below the surface is wet despite you not watering the plant recently, it means that you have overwatered your wisteria.
  • Soft stems – Too much moisture causes the stems of your wisteria to lose rigidity and become soft.
  • Edema – Edema is caused by water pressure in the cells of the leaves being too high, which causes them to burst. From the outside, you can notice edema in the form of brown patches on the leaves.

Iron Deficiency

Iron deficiency in your wisteria plant causes a condition called leaf chlorosis, where the leaves of your plant start turning yellow.

Leaf chlorosis affects the freshly-grown leaves first and moves towards the older leaves if untreated, which is an important detail that can steer you in the right direction.

This problem is often caused when the pH level of the soil is too high. Even when there is a sufficient amount of iron present in the soil, your wisteria won’t be able to absorb it if the soil is too alkaline.

Fortunately, finding out if the pH level of your soil is quite simple. By purchasing a soil test kit and following the instructions that come with it, you can quickly find out if the soil of your wisteria is too alkaline for it to absorb iron.

Poor Soil Drainage

When the soil of your wisteria is drained poorly, it eventually becomes waterlogged.

A waterlogged soil means that your plant will have difficulties absorbing water and oxygen through its roots, meaning that it won’t be able to get a sufficient amount of nutrients.

The symptoms of poor drainage are quite similar to overwatering. As a result, you may be observing symptoms of overwatering not because you have overwatered your plant but because of poor soil drainage instead.

Viruses

In some cases, aphids can bring plant viruses to your wisteria. These viruses can quickly multiply in the tissues of your wisteria and start affecting all of the leaves.

Wisteria leaves that are affected by a plant virus show symptoms such as leaf veins becoming white or yellow, yellow mottling and flecking, and mosaic-shaped discoloration on the leaves.

As plant viruses can not be diagnosed by appearance alone, you should get your plant tested if you have any doubt that your wisteria may be affected.

Fungal Diseases

Fungal diseases such as leaf spot disease can cause the leaves of your wisteria to become yellow as well.

That being said, leaf spot disease starts with small yellow spots on the leaf that turn brown eventually rather than causing the entire leaf to become yellow at once, making it easily distinguishable, especially when caught early.

Pests

Lastly, pest infestations could be the reason behind the leaves of your wisteria becoming yellow.

Pests such as aphids and scales feed on your and plant damage its integrity, causing leaves to turn yellow and become misshapen.

Below are some other symptoms that are caused by pest infestations.

  • Visible pests around the leaves – Even though they can be hard to detect, sometimes it’s possible to see the pests around the leaves of your wisteria. Don’t forget to examine the undersides of the leaves, as pests usually reside there.
  • Sticky substance around the leaves and the stems – Aphids and scales leave a substance called honeydew around the leaves and the stems of your wisteria, which has a fairly sticky feeling.
  • Bumps on the branches. Bumps on the branches could be a sign that your plant is infested with scales.

Alongside these symptoms, common symptoms of an unhealthy plant, such as stunted growth, are usually present as a result of a pest infestation.

What Should You Do to Fix Yellow Wisteria Leaves?

Now that we have talked about identifying the reason behind the leaves of your wisteria turning yellow, it’s time to get into how you can resolve it.

Underwatering

To save an underwatered wisteria, you will need to hydrate it as soon as possible.

To do so, start by placing the pot in a bucket full of water and let it stay there for roughly 30 minutes. This process will allow the entirety of the soil to absorb water again and soften the hardened parts.

After 30 minutes have passed, let the soil drain, and keep the plant watered. If the process has been successful, you should see new growth and green leaves in no time.

To ensure that you don’t underwater your plant again, check the moisture status of the soil every day and water the plant if it feels dry.

Overwatering

When it comes to overwatering, the solution is quite simple.

As you may predict, all you have to do is to stop overwatering your wisteria, and it will go back to its good health in no time.

That being said, overwatering can easily cause serious conditions such as root rot, in which case you most likely won’t be able to save the plant unless you catch the problem very early.

Iron Deficiency

As the iron deficiency problem is caused by the soil being too alkaline, you will have to reduce the pH level to resolve the issue.

To do so, you can add soil sulfur to the pot and let it do its magic.

That being said, as soil that is way too acidic can also be harmful to your plant, make sure that you observe the pH level as you add the sulfur.

Poor Soil Drainage

While poor soil drainage can be a result of a few different things, here are a few tips you can follow to take care of the situation.

  • Use a breathable pot – Using a terracotta, ceramic, or wood pot is a great way to ensure that your plant gets enough airflow, allowing the soil to drain.
  • Use a pot with drainage holes – Drainage holes are crucial to ensure that the excess water can leave the soil.
  • Add draining materials to the soil – Mixing materials such as perlite into the potting mix improves the drainage.

Viruses

Unfortunately, if your wisteria is affected by a plant virus, there is no cure for it.

That being said, the extent of harm done by a wisteria virus often stops at the discoloration of the leaves, meaning that your plant will most likely survive.

Fungal Diseases

The best way to combat fungal diseases is to use fungicides that will kill the disease off.

As some fungicides can be toxic to humans (and animals), make sure that you do your research before using one on your plant.

Pests

If your wisteria is facing a pest infection, the best course of action is to clean your plant with water and insecticidal soap.

By spraying insecticidal soap on your plant and rinsing it with water, you should be able to quickly get rid of a pest infection if you have caught it early.

Wrapping Up

As numerous things can cause the leaves of your wisteria to turn yellow, closer examination is a necessity to pinpoint the problem and resolve it.

While commonly encountered plant problems such as underwatering, overwatering, and poor soil drainage are often the culprits, you shouldn’t overlook factors such as fungal diseases, viruses, pests, and iron deficiency either.

If you have managed to discover the problem early, your wisteria will go back to its usual health in no time as long as you apply the required care to resolve the issue.