Alocasia Leaves Turning Yellow: 13 Causes and Solutions

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The Alocasia plant is one of the most magnificent plants on the planet, but it is also temperamental. Even with our best efforts, their leaves sometimes turn yellow.

In most cases, what causes Alocasia leaves to turn yellow is overwatering. Other possible causes are poor-draining soil, inadequate light, low humidity, nutrient deficiencies, lack of warmth, fungal diseases, pest infestation, and more.

This post explores the most common causes of Alocasia leaves turning yellow and provides tips for fixing them. Ideally, you will be able to bring your Alocasia back to full health in no time if you catch the problem early and only have a few yellow leaves on your plant.

Why Are Alocasia Leaves Turning Yellow?

1. Overwatering

Overwatering is often the culprit for yellowing leaves on Alocasias. Check the soil immediately and review your watering routine. Despite their preference for moist soil, Alocasias are susceptible to overwatering.

If you believe your plant is overwatered, you should:

• Unpot the plant gently and examine the roots: they should be white, firm, and earthy-smelling. Brown, squishy, and foul-smelling roots indicate rot. Ensure that all infected parts have been removed and then repot them with fast-draining, dry soil.
• Remove the yellow leaves from the plant and transplant it into soil that is drier.
• Check your plant every two days to see if it is improving.
• Water the plant again after about a week.

Alocasia Plant Watering Tips

• Let the soil dry out for about three inches before you water it.
• It is important to water evenly so that all parts of the soil are saturated.
• Check whether you are watering the plant appropriately by sticking your finger into the soil.
• Ensure that your Alocasia pot has a drainage hole, so water doesn’t accumulate at the bottom. Water the soil thoroughly and drain out any excess water.

There are Alocasia species that prefer dry soil between waterings, and there are others that prefer moist soil. Keep an eye on the plant and water it according to its needs.

Maintain a regular watering schedule for your plant. By being consistent, you can avoid flooding or droughts. Putting off watering or watering your Alocasia inconsistently can lead to overwatering or underwatering.

Consider investing in a moisture meter like the one below for your Alocasia and other plants as well. Moisture meters are useful for checking the moisture levels of soil to ensure that they are within the ideal range.

2. Water Quality

Heavy metals in unfiltered water can interfere with the growth of your plants. Water from the tap may have calcium and magnesium in it, which cause a white powdery layer to form on the soil’s surface. The excess salts can cause dehydration of the roots.

A The Ohio State University expert states that excess salts can lead to stunted growth, dried roots, and yellow leaves.

Alocasia plants do not tolerate contaminated or heavily mineralized water. As a result, the tips and edges of the leaves will turn brown, and yellow leaves will start to appear.

Make sure you chemically neutralize tap water with some de-chlorinator drops before using it. Try switching to purified water or rainwater if the yellowing leaves persist.

3. Soil Type and pH

Continuing our discussion of watering, keep in mind that any yellowing can be caused by poor soil conditions. For this reason, you should use soil that is porous and well-draining, and prevent overwatering from stressing your plants.

There is no better soil mix for Alocasias than an Aroid mix. Its ideal soil contains lots of amendments, including bark and perlite, for fast drainage. We recommend a soil mix consisting of 60% coco husk and bark, 20% soil, and the remainder a mixture of horticultural charcoal, perlite/vermiculite, and sphagnum moss. Make sure the soil does not have any rocks as this could damage your plant’s corms.

To increase the soil’s ability to hold water, you can add peat to the mixture. However, depending on your particular Alocasia, peat might hold too much moisture if it makes up a large percentage of the medium.

Besides this, Alocasias require a good pH in their soil. Acidic soil is ideal for these plants, with a pH between 5.5 and 6.5. Any pH higher than this can damage the plant’s health, which can result in yellowing and browning.

It is the pH of the soil that determines the availability of nutrients to plants; no amount of fertilizer can help your plants if they’re planted in soil with an incorrect pH. To find out what your soil’s pH level is, you can purchase a soil test kit like the one below. Most products come with recommendations on additives for adjusting the pH to ideal levels.

Your soil must also be enriched with organic matter to provide your plants with the nutrients they need. A lack of organic matter in your soil can cause your plant to yellow because it lacks nutrients.

4. Light Exposure

Lighting issues are commonly responsible for the yellowing of Alocasia leaves. Due to their natural habitat in the tropical shade, Alocasias are sometimes described as low-light plants, but forest shade, compared to most indoor environments, is quite bright. When indoors, Alocasias prefer to be close to a bright south-facing window while protected from direct sunlight.

As the seasons change, Alocasia’s leaves can become pale and yellow as the sunlight rays become less intense. You may want to consider moving your plant from a moderately lit location or adding a grow light if you notice pale growth.

Alocasia plants’ leaves turn yellow when inadequate light is available, but they can also turn yellow when excessive sunlight is present. Yellowed or brown foliage as well as scorched or bleached leaves indicate excessive exposure. The best solution is to place your plant in an area with indirect sunlight, but the light fills the entire room. You can also use sheer curtains as a quick fix!

5. Temperature Shock

During periods of low temperatures, alocasia leaves turn yellow and decline. According to research, the houseplant enjoys a warm environment. An alocasia thrives best between 65°F and 85°F (18°C and 29°C).

Cool indoor temperatures may deprive your Alocasia of the heat it needs to thrive. Several varieties are difficult to manage indoors because of their strict preference for the warm side of the spectrum. A heating pad can be used to keep the plants’ roots warmer than room temperature.

Due to its inability to withstand frost, the plant suffers at temperatures below 55°F (13°C). When your alocasia leaves turn yellow during winter, it is an indication that there isn’t enough warmth to support them.

Also, make sure the temperature does not fluctuate too rapidly or widely. Therefore, do not place your plant near an air conditioner or heater.

6. Low Humidity

Humidity is often overlooked when caring for houseplants, but a lack of it can cause Alocasia leaves to turn yellow. As a tropic native, Alocasias thrive in high humidity. While they are capable of growing at lower humidity levels, the ideal humidity level for them is 60%.

An Alocasia plant that is exposed to low humidity levels will develop yellow leaves with brown margins. Consequently, all the leaves will turn yellow. This is more pronounced in winter as heating and reduced ventilation make the air much drier. Therefore, when the heating is on, you should up the humidity even more rigorously.

To increase the humidity in your Alocasia, follow these simple steps:

• If there is good lighting, place your plant in the kitchen or bathroom where the humidity is higher.
• Mist the plant. However, make sure there is sufficient ventilation as wet leaves are prone to rot.
• In moderately humid climates, group your Alocasia plant with other tropical plants.
• Place your plant on a pebble tray filled with water.
• If you do not live in a tropical climate, consider using a humidifier for your plant.
• Give your plant a rinse. This also helps remove dust and pests from the leaves.

7. Nutrient Deficiency

Despite not being the most common cause, if the soil is not changed or fertilized for a prolonged period of time, Alocasia can be starved of minerals and vitamins (particularly nitrogen). It is important to feed these houseplants regularly every two to four weeks during the warmer months. During this time, their growth is brisk. If there is nutrient depletion, they can retire older leaves to save resources.

If you suspect a plant lacks nutrition, don’t simply feed it more. Depending on the nutritional deficiency the plant has, choose the appropriate fertilizer. The following tips may help:

• Yellow veins on the leaves indicate magnesium and sulfur deficiencies. Using Epsom salt and manganese sulfate before watering will help treat this.
• In mature and older leaves, uniform yellowing in the veins indicates nitrogen deficiency. Watering it with nitrogen-rich fertilizer can help treat it.

For gentler transitions, set up a regular feeding schedule: if you haven’t been fertilizing, set one up; if you have already been fertilizing, increase the amount a little.

A liquid fertilizer that penetrates the root ball and soil is the best way to fertilize. Be sure to dilute the fertilizer to one-half the label recommendation and water your plants prior to fertilizing. In contrast to chemical fertilizers, organic fertilizers do not need to be diluted and are less likely to burn sensitive roots.

Keep an eye on the foliage for a few weeks after application. Then, if there is no improvement, return to the plant’s original feeding regimen and see if there are other factors contributing to the problem.

Continue feeding the correct dose if you see an improvement in the plant’s color or vigor. If there’s no improvement, don’t keep increasing, as you might overfertilize it.

Related Post:
100+ Alocasia Varieties With Names and Pictures

8. Fertilizer Burn

Feeding an Alocasia too much can be dangerous. Symptoms include burnt edges and tips of the leaves. If the roots of the plant are burned by fertilizer their leaves will yellow and die.

Slowly adjust your established feeding regimen and observe how the plant responds. Spring and summer are the best times to feed; winter is when to stop fertilizing.

It is possible for the soil to become contaminated with residual salts after overfertilization. A good practice is to flush the soil mix when you water, or at least once a month. Make sure to thoroughly soak the soil and let the excess water drain out.

9. Pests Infestation

Plants are plagued by insects no matter what their circumstances are. There is nothing these little pests love more than to make plant lovers’ lives difficult.

Among the pests that affect Alocasias are spider mites, aphids, scale, thrips, and mealybugs. Those big and juicy leaves are attractive to pests, so be sure to check your plant regularly.

Yellowed and/or mottled leaves are signs of an infestation, which saps the life out of plants. Insects can damage plants in a variety of ways, such as by damaging their cells, causing stems to deform, or even destroying entire plants.

In most cases, you can spot pests by examining the leaves closely. As they often hang out at the stem joints and underside of leaves, we always use a magnifying glass to inspect them. In the event that you find a pest on your plant, do your best to keep it away from the other houseplants in your house. Plants can contract pests if they are too close together, so isolate your infected plant as soon as possible.

Spider Mites

Often, spider mites congregate near leaves’ main veins and weave small webs. If your Alocasia plant is infested with spider mites, spray it with water from a garden hose or use the shower to rinse off the mites. Then, spray isopropyl alcohol, neem oil solution, or insecticidal soap over all the leaves and stems.

Mealybugs

Fuzzy, white spots on the leaves are an indication of mealybugs. If the leaves are infested with mealybugs, use isopropyl alcohol to wipe them. Neem oil and insecticidal soap are also generally effective.

Scale

Rinse your plant and trim out any damaged foliage if your plant is infested with scale. Afterward, spray the leaves and stems with insecticidal soap spray or neem oil solution.

Every four to six days, check the plant and repeat the treatment. You’ll probably have to repeat it a few times to completely eliminate the pests and their eggs.

Maintaining a dust-free environment is one way to prevent infestation. Dusty conditions encourage the growth of certain pest insects. When you wash off or wipe off the leaves frequently, you prevent bugs, promote better circulation, and reduce stress on the plants.

10. Fungal Diseases

The yellow color of Alocasia leaves can be caused by bacterial and fungal diseases.

Among the most common diseases that affect Alocasia plants is root rot. It is caused by overwatering the houseplant. Roots that are damaged usually smell foul and have brown patches. The rotten roots should be cut off with sterilized shears.

Yellow patches also appear on the leaves and stems of Alocasia plants when they suffer from rust, a fungal disease. There are times when the whole leaf turns yellow and falls off. Plants are susceptible to rust when their leaves are damp.

Fungicides are the best way to combat fungal diseases. Several products are available on the market, and we have good experience with Bonide 775 Copper Fungicide:

Here are some tips to prevent bacterial or fungal disease:

• Make sure the plant is not exposed to excessive humidity.
• Increase air movement in the area where the Alocasia plant is located.
• Pruning and propagating should be done with sterilized tools and gloves.
• Avoid overhead watering or misting the plant if there is poor air circulation.
• Keep the area around the plants clean by removing any fallen leaves.

11. Dormancy

Dormancy can be triggered by sudden and dramatic changes in the environment, for example from the greenhouse to your home. During this adaptation process, the leaves may turn yellow and die off. If this happens, it may be beneficial and ideal to move an Alocasia plant to a new site. In some cases, changing the location of the distressed Alocasia plant will cause it to respond to yellow leaves.

If your Alocasia has become dormant, you should keep the soil on the drier side. After that, you can water it adequately. After some months, the dormant Alocasia plant will grow again.

12. Transplant Shock

When a plant suffers transplant shock, it withers, fails to thrive, and develops yellow leaves. Wilting leaves after transplanting can be caused by how you handled the plant when repotting. Transplant-stressed Alocasias can be cured, but recovery will take time and care.

The occurrence of transplant shock in plants is almost unavoidable. However, you can minimize transplant shock in some cases with these methods:

• Water your Alocasia plant thoroughly after transplanting.
• Keep the rootballs moist when transplanting.
• Try not to disturb the roots too much.

Following are some solutions that may be helpful if the Alocasia has suffered transplant shock and has yellowed leaves:

• Make sure the soil is kept moist by watering it regularly.
• Ensure proper drainage for the Alocasia plant.

13. Natural Aging Process

In the case that none of the above factors apply to your Alocasia, natural aging could be the explanation.

There will always be occasional yellow leaves on your Alocasia, even if it receives adequate light and is correctly watered. The Alocasia plant, like most houseplants, occasionally drops its oldest, lowest leaves, which turn yellow before falling off. Often, this occurs when a new leaf is emerging.

Nothing you are doing wrong is causing this. This is totally normal. It isn’t a big deal if only one or two leaves turn yellow every few months. In general, as long as your Alocasia keeps putting out new, healthy leaves, it should be fine.

Nevertheless, we recommend that you monitor how often the leaves deteriorate and fall so that shedding doesn’t increase. Try looking at the reasons above again if you find that more leaves are turning yellow in order to determine what is causing this.