Agaves make stunning ornamental plants in and around your house, so it’s disheartening to see the leaves yellowing or browning. What could cause leaf discoloration and how can you save your agave? 

You’ll learn why agave leaves turn yellow or brown and the exact steps you need to take to fix the issue. 

Why Are My Agave Leaves Turning Yellow?

Here are reasons why your agave leaves might be turning yellow: 

Too Much Water 

Overwatering your agave plant is one of the most common reasons for the leaves turning soft, mushy, a slimy yellow, and browning.   

If you’ve overwatered the agave, the soil doesn’t drain well enough and has become waterlogged. Since succulents like the agave store water in their leaves and stems, too much water causes the plant to swell up and look sick. 

How to Fix Overwatering Your Agave

Stop watering your plant when you notice the leaves are soft and have started to yellow. Let the plant dry out completely. 

Only when the top few inches of the soil is dry, water your agave. To check if the topsoil is dry, stick your index finger into the soil close to the crown of the agave. The soil should be dry up to your first knuckle. 

Once your agave has started to recover, continue watering your agave the right way to ensure it thrives. Also make sure the soil the agave is planted in is a well-draining soil that is suitable for succulents. 

Another option is to transplant your succulent in a well-draining potting mix. If the “old” soil is waterlogged, it may take too long to dry out and then it might be too late for your plant too. So repotting your agave in a suitable succulent mix and in a pot that has drainage holes can save your plant. 

Sometimes, an overwatered plant may be beyond saving. If this has happened to your agave, it won’t recover when you stop watering it and will be dead by the time the soil has dried out. In this case, it is best to plant a new agave and follow the best care instructions so your plant can thrive. 

Not Enough Nutrients in the Soil

Another reason why your agave’s leaves are yellowing is because of a lack of nutrients. A deficiency in magnesium or acidic soil could be why the leaves are yellow. Magnesium is an essential component of the chlorophyll molecule, which is responsible for plants being green. 

This usually doesn’t happen overnight; instead, it happens over a few years. The agave will feed off the nutrients in the potting soil, but eventually the nutrients will be used up and need to be replaced. 

So when there isn’t enough nutrients in the soil, the leaves of the agave will discolor and turn yellow. The plant may also appear misshapen because its growth has been stunted. 

How to Fix a Lack of Nutrients in the Soil 

To fix a lack of nutrients, repot your agave in a new pot with fresh soil. Another quick solution is to add fertilizer to the pot to replenish the nutrients in the soil. Succulents don’t need a lot of fertilizer, so dilute it to half the recommended dose. 

To add more magnesium to the soil, mix 1 teaspoon of Epsom Salt in one gallon of water and spray this mixture onto the soil. 

When it’s growing season, feed your agave every two weeks to ensure the soil is nutrient rich and to prevent your plant’s leaves from yellowing.  

Transplant Stress 

Potted agaves need to be transplanted when they become root bound or grow to be too big for the container. Not following the best practices for how to transplant your agave results in transplant shock. This is when the plant goes into stress, which can cause it to wilt and/or the leaves to yellow. 

How to Fix Transplant Shock 

If your agave plant has gone into shock after it has been repotted, check the drainage of the new pot. Are there sufficient drainage holes so the soil doesn’t become waterlogged and your plant dies? If not, add a few more drainage holes to the pot. 

If you’ve relocated your newly repotted agave, then check the temperature and humidity in the new area. If the temperature isn’t suitable for your agave, move the succulent back to where it was growing before. 

If there are any dead or yellow leaves, remove these. This will make space for new growth. 

Monitor your agave every day. Ensure it doesn’t need water or more sunlight. Sometimes a transplanted agave needs a few days to recover from the stress of being transplanted. It will eventually thrive. 

Not Enough Sunlight 

If your agave doesn’t get a minimum of six hours of sunlight every day, then a lack of light could be a reason for the leaves turning yellow. Without sufficient light, the succulent can’t make chlorophyll and photosynthesize. As a result, the leaves yellow because there isn’t enough chloroform.   

How to Fix a Lack of Sunlight 

If you think a lack of natural light is the cause for your agave leaves turning yellow, then move the plant to a spot where it can soak up more sun. For indoor agaves, move them to a west or south-facing window. 

Humidity

While agaves prefer hot temperatures, generally above 100℉, these succulents can tolerate cooler temperatures down to 60℉. Low temperatures may create moisture on the topsoil, which encourages fungi and pest infestations to take root. 

A warm environment where there is a lot of humidity in the air or where agaves may be densely planted with no air flow causes the same issue with infestations. These infestations cause a shortage of nutrients and water supply for your agave and the leaves yellow.    

How to Fix Humidity for Your Agave 

After checking the temperature and finding that the temperature is too low or it is too humid, relocate your agave to a better area. 

Also ensure there is sufficient ventilation around the agaves so humidity can’t easily build up around the plants. This may mean transplanting some agaves. 

Pest Infestations

Pest infestations like the agave snout weevil and sap-sucking insects like spider mites, aphids, and mealybugs can cause your agave leaves to discolor. 

How to Fix Pest Infestations 

Firstly, check your agave for pest infestations and identify which pest you are dealing with. Then buy the appropriate insecticide and spray your plant leaves – both the upper and lower portions – and around the base of the agave.

Why Are the Bottom Agave Leaves Turning Yellow?

Here are the reasons why the bottom leaves of your agave are turning yellow: 

Root Rot 

If the roots of your agave are rotting, they can’t absorb the nutrients or water needed for growth. As a result, the agave leaves start to yellow. 

A common reason root rot occurs is overwatering. Besides yellow leaves, your agave will also start to wilt and can die within a few weeks if the root rot isn’t treated timeously.  

How to Fix Root Rot 

Check if root rot is indeed the cause of your agave leaves yellowing and the plant wilting. You can gently remove the agave from the soil, clean away excess soil from the roots, and check what the roots look like. If the roots are soft and brown, it is root rot. 

Cut away all the dying and dead roots and any dried or discolored leaves. Ensure there is a balance between how many roots are left in comparison to how big the plant is. You want to ensure that the roots can handle the leftover healthy leaves, and if not, then prune some more leaves.  

Spray the healthy roots with an antifungal solution and then repot the agave into a new pot and new potting soil. 

Crown Rot

Crown rot occurs because of overwatering, excess humidity, pathogens like the bacterium Erwinia and fungus Fusarium in the soil, or after the agave snout weevil starts eating and injecting bacteria into the plant. 

When crown rot starts to set in, the lower parts of your agave will start to yellow and then eventually brown. The leaves will wilt and the agave will die. 

How to Fix Crown Rot 

If you catch crown rot early, spray your agave with fungicides like neem oil or thiophanate methyl and prune any damaged leaves that show lesions or chew marks.

For severe crown rot, dig up your agave and remove all the soil around the roots. Prune the whole crown and any rotting areas. If there is any agave left, spray it with fungicide and replant in a new location. Sterilize the soil the agave was planted in before planting a new plant in it.   

Why Are My Agave Leaves Turning Brown?

If your agave leaves are turning brown, one of these reasons could be the culprit: 

Sun Damage or Leaf burn 

If your agave receives a lot of bright sunlight or your area experiences a heatwave, then brown spots will appear on the leaves. These are leaf burns, the equivalent of sunburn. 

The brown spots damage the aesthetic look of the plant and they leave a permanent mark on your agave’s leaves. Eventually, the leaves will die and fall off as new leaves grow.    

How to Fix Agave Leaf Burn

When you notice that your agave is getting leaf burn, move it into the shade. 

If you want your agave to stay in direct sunlight, then it is best to slowly acclimate the plant and gradually increase the sun exposure the agave gets.

Not Enough Water

Your agave’s leaves can turn a crispy brown when it doesn’t get enough water. The leaves will brown and shrivel up when they are damaged by the sun and the soil is too dry because of the heat. 

How to Fix Underwatering of Your Agave 

This would seem like an easy solution, right? Simply water your agave. Let the water make its way to the roots so it can be absorbed and your agave should perk up. 

Then make sure you follow the correct procedure for watering your agave: let the topsoil dry thoroughly before watering your agave. 

Just a quick tip: it’s much easier to save an underwatered agave than it’s to save an overwatered one, so when in doubt, rather give your succulent less water than too much.  

Fungal Leaf Spot

If you see black or brown spots on your agave leaves, your succulent is most likely suffering from anthracnose, or fungal leaf spot. The fungal spores are distributed via the air or water that splashes. 

If your agave is in an area that is humid or very shady, then it’s at a higher risk of fungal leaf spot.  

How to Fix Fungal Leaf Spot 

Immediately isolate your agave to prevent the fungus from spreading to your other plants. Move your agave to a spot where there is more sunlight. 

Prune the infected leaves and throw them away using a garbage bag. Lastly, apply a fungicide to your agave to prevent the fungal leaf spot from recurring.

Author

My name is Dan and I am the owner of this blog. I have been tending to the garden ever since my parents moved to a home with a large garden when I was a teenager. Gardening takes time and patience. Let me show you the way to a beautiful backyard.