Aloe vera is a tough, semi-tropical plant that comes from North Africa and the SW Arabian Peninsula. It can survive in very harsh conditions. It can grow in poor soils in hot, dry, sunny places with little water, but it can also handle dappled sun or part shade, which means it can be grown successfully indoors near a window that lets in lots of natural light.
When grown outdoors, Aloe vera plants will flower. Around early spring, they have clusters of yellow or orange tubular flowers that hang down from a long stalk that grows from the middle of the plant. They tend not to flower when grown indoors as houseplants.
Aloe vera is a popular houseplant known for its medicinal properties. This succulent plant is easy to grow and care for, thriving with minimal water and sunlight. However, despite its low maintenance nature, aloe vera plants can develop issues that lead to yellowing leaves.
Common Causes of Yellowing Aloe Vera Plants
There are several key reasons an aloe vera plant may start to turn yellow. Identifying the cause is crucial to restore your plant’s health.
Overwatering
Too much water is the most common cause of yellow aloe vera leaves. As a succulent aloe vera stores water in its thick fleshy leaves. It prefers infrequent but deep watering. Overwatering causes root rot, preventing the roots from taking up nutrients and water. The saturated soil also lacks oxygen. Without oxygen reaching the roots, the plant cannot transport moisture and nutrients to the leaves, leading to yellowing.
To avoid overwatering, allow the soil to completely dry out between waterings. Only water when the top few inches of soil feel dry to the touch. Make sure the pot has drainage holes and well-draining soil to prevent waterlogging.
Underwatering
While aloe vera doesn’t need frequent watering, allowing it to completely dry out for too long can also cause yellowing leaves. If the soil dries out completely, the roots don’t get enough moisture to supply the leaves. This leads to dehydration and yellowing.
Check soil moisture by sticking your finger into the pot. Water thoroughly when the top few inches feel dry. Don’t wait until the leaves start drooping from dehydration.
Sudden Environment Changes
Aloe vera thrives on consistency. Any sudden changes in temperature, sunlight, or location can shock the plant, causing stress and yellow leaves. For example, moving an indoor aloe vera outside during summer can sunburn the leaves. Temperature drops during winter can also damage the leaves.
When making any changes to light or temperature conditions, do it gradually over 7-10 days. This gives the plant time to adapt without going into shock.
Cold Temperatures
Aloe vera is a tropical plant that prefers temperatures between 55-80°F. Prolonged exposure to temperatures below 55°F can turn leaves yellow. The cold damages the plant’s cells, causing yellow, mushy leaves.
Keep aloe vera away from drafty windows during winter. Move outdoor container plants to a sheltered location safe from frost. Consider moving plants indoors or using a greenhouse if temperatures drop too low outside.
Poor Drainage
Aloe vera needs soil that drains quickly. Dense potting mixes or containers without drainage holes hold too much moisture, leading to saturated roots. The roots are unable to access oxygen, preventing them from taking up water and nutrients. This starves the leaves of moisture and nutrients, causing yellowing.
Use a porous potting mix made for cacti and succulents. Add perlite or gravel to regular potting soil to improve drainage. Make sure the pot has drainage holes at the bottom.
Nutrient Deficiencies
Lack of key nutrients like nitrogen and iron can cause aloe vera leaves to turn yellow. Nitrogen deficiency typically affects lower leaves first. Iron deficiency typically causes new leaves to yellow while the veins remain green.
Use a balanced houseplant fertilizer to provide aloe vera with essential macro and micronutrients. Fertilize in the growing season from early spring to summer.
Sunburn
Too much direct sun can scorch aloe vera leaves, turning them yellow, brown, or reddish. Native to tropical, arid regions, aloe vera thrives on bright, indirect sunlight indoors. Direct sunlight through a window can sunburn the leaves.
Place aloe vera near an east or west-facing window for bright, gentle light. Filter harsh sunlight with a sheer curtain. Rotate the plant daily to ensure even sun exposure.
Pests
Sucking pests like spider mites, mealybugs, and aphids can drain moisture and nutrients from aloe vera. Their feeding activity causes stippling, discolored spots, and yellowing leaves.
Check for tiny bugs on the undersides of leaves. Wipe leaves with a damp cloth to remove any visible pests. Use neem oil or insecticidal soap to get rid of infestations. Isolate affected plants to prevent spreading.
Diseases
Fungal diseases like root rot, leaf spot, and soft rot can cause aloe vera leaf yellowing. Overwatering and poor drainage encourage fungal growth. Inspect leaves and roots for signs of infection like black, mushy spots. Improve watering practices and use fungicides to treat diseases. Discard severely infected plants to prevent spreading.
How to Treat Yellow Leaves on Aloe Vera
Once you’ve diagnosed the cause of yellowing, take prompt action to restore your aloe vera’s health. Here are some tips:
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Adjust watering to allow the soil to partially dry out between waterings. Water less frequently but thoroughly.
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Move the plant to a location with bright, indirect light. Slowly increase light exposure to prevent sunburn.
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Keep indoor aloe vera plants away from cold windows and drafts during winter. Move outdoor containers to a sheltered location.
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Repot in a container with drainage holes and well-draining potting mix.
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Fertilize with a balanced houseplant fertilizer to provide key nutrients.
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Inspect for pests and diseases. Isolate and treat any infestations.
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Prune off badly damaged yellow leaves using a sterilized knife or shears.
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Allow time for the aloe vera plant to recover and produce new healthy growth after treatment.
Preventing Future Yellowing
With proper care, you can keep your aloe vera thriving with vibrant green leaves. Follow these tips to prevent yellowing:
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Water only when the top inches of soil are dry. Avoid overwatering.
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Use a porous potting mix to prevent waterlogging. Add perlite if needed.
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Fertilize during the growing season to provide nutrients.
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Give bright, indirect sunlight indoors. Rotate the plant to prevent one-sided growth.
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Keep indoor temperatures above 55°F in winter. Shelter outdoor plants from frost.
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Inspect regularly for pests and remove by hand or use organic treatments.
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Repot every 2-3 years using fresh potting mix. Trim off any crowded growth.
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Acclimate plants slowly before moving to new lighting conditions or locations.
With the right care, your aloe vera will reward you with lush, vibrant evergreen leaves. Pay attention to its needs, and you can enjoy this easy-care succulent for many years.
The Symptoms of an Unhealthy Aloe Vera Plant
When Aloe vera plants are subjected to unfavourable conditions, they may show some of the following signs:
- As time goes on, the leaves lose their green color and turn straw yellow, then light brown.
- Leaf tips darken and dry out.
- Leaves dry out and wither.
- Leaves become soft and mushy, and begin to rot.
A pair of unhealthy Aloe vera plants that have been overwatered and exposed to sudden cold weather.
What Makes Aloe Vera Plants Unwell and How to Prevent It
Plants become stressed when they are put in situations they don’t like and start to show signs that they aren’t healthy.
What are the conditions that can stress Aloe vera plants?
Aloe vera plants lose their leaves when they get too much water. The leaves will turn yellow, brown, and eventually rot away.
Testing for overwatering is quick and easy:
- You can use a garden hand trowel to check if the soil is wet if the plants are in the ground.
- If plants are in pots, pick the pot up and feel how heavy it is. If it feels too heavy, it means that the growing medium is full of water.
Aloe vera plants don’t need much water. If they’re growing in containers, water once a week in summer and once every two weeks in winter. All tropical and subtropical plants don’t like too much water when it’s cold, as it rots their roots.
What about rainfall?
If you grow Aloe vera outside in pots or containers, don’t leave them out in the rain during the winter. Instead, put them somewhere that will protect them from the rain. They do best next to a sunny house wall where the roof hangs over and keeps them dry in the rain. I have pots of aloe vera growing against a west-facing wall. The winter sun warms the wall in the afternoon and raises the temperature around the plants at night.
If you plant aloe vera in the ground and it rains, the plants will be fine as long as the soil drains well in the winter. Soils that are heavy in clay should be amended before planting. The soil in the planting area needs to be mixed with compost (about 25% by volume) to make it drain better.
Can the size of pot make a difference?
If you put too much soil in a plant’s pot, it can become too wet. All succulents, including aloe vera, need to be grown in soil that drains well. You shouldn’t use garden soil in pots because it turns into mud when it gets wet! Even if you use potting mix, which drains well, if the pot is too big for the plant, its small roots won’t be able to soak up all the water, and the growing medium will stay too wet for a long time. This has the same effect as overwatering on the plant.
Aloe vera plants like to be snug in their pot and have a lot of roots, so when you move them, only move them up to the next size pot and not into a pot that is too big for them. Give the plant around 3-4 cm (1-1 ½”) of space all round the sides in the new pot. Transplant Aloe vera plants every two years to freshen to growing medium and aerate the roots.
My Aloe Vera Plant is Turning Yellow
FAQ
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Should I cut off yellow aloe leaves?
What does an underwatered aloe look like?