What Causes White Leaves on Plants? (Causes & Solutions)

My Pothos and Philodendrons were doing fine a month ago, but since last week the deep green leaves have started whitening on the edges.

To make matters worse, a few of them dried up and abruptly became solid white. If it sounds scary, remember this could happen to any houseplants.

Generally, Plant leaves turn white mainly due to diseases like powdery mildew, downy mildew, ring spot, sun scorch, and over or lack of nutrients. Poor water quality, Edema, alkaline soil (wrong pH), and pest infestation are other plausible reasons.

White spots on plant leaves
Plant leaves turn white due to different causes, such as powdery mildew, pest infestation, sun scorch, improper watering, etc.

Therefore, whitening foliage is not unique to any plant or gardener.

Remember, bad growing conditions and excess of anything will affect a plant’s health, leading to foliage discoloration.

Read on to discover the causes of houseplant leaves turning white and their solutions.

Is it Normal for Plants’ Leaves to Turn White?

Expecting to see beautiful green or colorful foliage is one reason why plant lovers care for houseplants. Seeing unusual hues on plant leaves, such as white, is quite unusual.

Remember, healthy houseplants are unlikely to exhibit whitening leaves unless affected by external factors.

Hence, seeing whitening leaves on plants is not normal and may indicate an underlying problem.

White spots on cucumber leaves
Witnessing white spots on leaves is common in popular houseplants.

In fact, your houseplant is already under severe duress when they begin showing whitening leaves.

The discoloration of plant leaves is mainly caused by wrong growing conditions and external factors like pests infestation, improper fertilization, improper watering, and diseases.

You would either witness these changes at the top-most leaves or bottom leaves. In any case, they are suffering.

Therefore, you should look for visible signs, including chlorosis, browning, hollow spot on foliage, sickly structure, or leggy growth.

Many of these common signs will accompany leaf whitening, but sometimes they will not.

However, please do not lose hope because it may be an excellent time to assess your plant and determine what may be affecting them.

Why are the Leaves of my Plant Turning White?

As previously mentioned, the plant leaves would turn white for many reasons.

Sometimes, the plant edges may turn white, while the half or entire leaf surface may change color other times.

Let us look at possible reasons for the plant leaves turning white and their solutions.

1. Powdery Mildew

Powdery mildew is mainly caused by Podosphaera xanthii, which may lead to white powdery leaf spots.

These white spots would appear as dots all over the single or multiple leaves, which may give an impression of solid white foliage.

Therefore, many gardeners call it white leaf syndrome.

powdery mildew on leaves
Powdery mildew is the most common cause of whitening leaves.

However, this problem is not usual. Any plant is susceptible to fungus infestation, especially Podosphaera xanthii, which causes powdery mildew.

Remember, powdery mildew thrives in humid conditions with moderate temperatures (65 to 80°F), such as during summer. 

Similarly, plants kept in shady locations and with infected species may also result in powdery mildew.

Do not worry yet; powdery mildew does not kill your plants, but you should treat it on time to prevent further damage.

Solutions

  • Start quarantining the plant and move it to a warm location with ample direct/indirect sunlight.
  • Make a spray of 1/4 teaspoon baking soda with 1 quart of water and spray weekly to remove the infection.
  • Otherwise, apply neem oil over the infected plant to treat and prevent further infection.
  • If none work, use fungicides containing copper sulfate and hydrogen peroxide to eliminate powdery mildew.
  • As a preventive measure, move your plant to a sunny location to allow condensation and dry dew quickly.
  • Improve air circulation by spacing the plants and keeping them around well-ventilated areas.
  • Use a room air humidifier to maintain an ideal humidity level around the plant.

2. Sun Scorch

Sun scorch is the primary reason the plant leaves will drastically change color from deep green to white.

Scorch, scalding, or burn will occur from keeping the plants exposed to the sun for significant hours each day.

If your houseplant is not used to absorbing direct sunlight, it may falter under intense sun, leading to excess transpiration.

Brown spots are the first signs of sun scorch, gradually developing into white patches.

Therefore, you can tell whether your plant is suffering from sun scorch.

It is commonly seen in summer when the sunlight is intense, and the temperature may rise over 90°F.

The recently transplanted plant will often suffer scalding due to denying the plant enough time to harden.

Solutions

  • Move your plant from the sun, especially the south-facing window or patio, into indirect sunlight.
  • Prune the heavily affected leaves so the plant can redirect the energy toward healthy growth.
  • Check soil moisture and water accordingly. Otherwise, submerge the pot in a water tub to let in the steam.
  • Wait a few weeks and hold back on fertilization until the problem subsides to prevent further damage to the leaves.

3. Low Lighting Condition

Keeping houseplants in low light will affect the chlorophyll production process, leading to the loss of natural leaf color.

There are mainly two factors that would cause leaf whitening.

  • Fewer hours of sunlight each day
  • Low lighting intensity

The extensive low lighting condition will also affect its food production, causing pale leaves.

Remember, plants require enough sunlight and in right intensity to thrive. Therefore, subjecting them to partial or low light will cause massive leaf discoloration.

Sunlight for mini watermelon peperomia
Low sunlight may cause the plant leaves to turn white.

The plant in dire need of light will also elongate its branches to reach the sunlight. This will be your telltale sign.

Here are a few plant types and their light requirement.

Light RequirementPlants
Bright Indirect (1000-2000 foot candles)Kentia palm, African Violet, English Ivy (Hedera helix), White Bird of Paradise, Chinese Evergreen (Aglaonema), Peace Lily (Spathiphyllum)
Medium Light (250-1000 foot candles)Spathiphyllum, African Violet, Begonias, Boston Fern, Croton
Low Light (50-250 foot candles)Snake plant, Dracaena, ZZ Plant, Spider plant, Lucky Bamboo, Arrowhead

Solutions

  • Immediately move your plant to direct or partial sunlight, depending on its nature and requirement.
  • Remove the leaves and leggy branches to redirect the energy toward healthy growth.
  • Place them in east or south-facing windows where they will get significant lighting.
  • Ensure that they get at least 6 hours of sunlight each day.
  • Move them under LED grow light (200W) for 10 to 12 hours a day if it is cold outside.
  • Check the soil moisture using a soil moisture meter before watering to ensure healthy root condition.

4. Edema (Oedema)

Edema (Oedema) is another concerning factor for plants, as excess water intake may lead to a sudden shock, resulting in flower leaves turning white.

This condition mainly occurs when you overwater your plant after depriving it for an extended period.

Image represents edema on the Peperomia leaves
Plant leaves show edema due to overwatering and over-fertilization by forming bumpy blisters on the leaves.

The roots can only take up as much water as the leaves can transpire, leading to cell rupture and damage.

They go into shock, affecting the leaves and leading to burnt white blotches or soaked patches that look unsightly. Luckily it is relatively easy to fix edema.

Solutions

  • Allow the soggy soil to dry a bit before watering again.
  • Let it re-adjust to the watering schedule to help it recover.
  • Trim off the heavily damaged leaves to redirect the plant’s energy toward healthy growth.
  • As a preventive measure, follow a strict watering schedule or check the soil moisture level before watering.
  • Avoid growing small plants in the larger pot; transplant it to an appropriately sized pot where the roots will take up only enough water.
  • You should water houseplants once or twice a week in spring and summer, depending on its need. 

5. Nutrient Deficiency

Every plant requires an optimal amount of essential nutrients to attain healthy growth and structure.

Depriving the plant of nutrients, especially macro, micro, or trace minerals, may lead to a sickly plant.

Here is what the lack of essential nutrients does to your plant.

NutrientsEffect on Leaves
NitrogenLower and older leaves turn completely yellow and later turns brown before dropping.
PotassiumThe margin of leaves turn yellow and then brown looking as if burned.
CalciumNew leaves turn yellow leading to blossom end rot with chlorotic spots developing along the margins.
MagnesiumLeaf margins of older leaves turn yellow leaving the veins green and shows white to light brown necrotic dots.
IronYoung leaves turn yellow leaving behind green veins, and older leaves nearly whitish with yellow to orange chlorosis.

They take nutrients from regular feeding of optimal NPK formula, homemade organic compost, or naturally decaying matter.

Remember, the soil or plant would not produce nutrients by itself, requiring external feeding.

Therefore, the plant will fail to produce chlorophyll or use sunlight for food production due to a lack of nutrition.

Iron deficiency will reduce the plant’s metabolism and turn its leaves yellow with white spots.

Similarly, white spots on the leaf’s upper portion may indicate manganese deficiency.

Solutions

  • Start with assessing the nutrition requirement of your plants and how often they should be fed, especially to combat leaf whitening.
  • You can easily buy the commercial formula from the market with appropriate NPK ratios such as balanced (1-1-1), 10-8-12, 30-28-30, etc.
  • Follow the manufacturer’s guidelines when applying the solution; whether to dilute the solution with water.
  • Feed the plant every one or two weeks or monthly in spring and summer with a liquid solution.
  • Spray the pellets once every three months for the granular formula (slow-release formula).
  • Water accordingly to allow the nutrients to spread across the potting soil.
  • Strictly reduce fertilizing in fall and winter when the plant goes into dormancy.

Read more about fertilizing different houseplants and treating over/under-fertilization

6. Alkaline Soil (Wrong pH)

The wrong soil pH level, a significantly higher pH level, will prevent the plant from taking essential nutrients from the soil.

Most indoor or outdoor potted houseplants will thrive in acidic, slightly acidic, or neutral soil pH levels (5.0-7.0).

For instance, Azaleas, African violets, Gardenias, Philodendrons, Anthurium, Monstera, and hydrangeas thrive in acidic to slightly acidic soil.

Anything above 7.0 pH level (alkaline) will prevent the plant’s feeder roots from quickly absorbing nutrients, choking it off plant food.

The more alkaline the soil is, the harder it gets for plants to absorb nutrients.

There are a few reasons why the potting soil will turn alkaline.

  • Lack of proper fertilizing
  • Introduction of calcium or magnesium carbonate in the soil
  • Using hard water that usually contains lime
  • Overwatering will leach off nutrients from the soil
  • Stale or old soil is less likely to absorb nutrients

Therefore, you should amend your soil to turn it acidic, according to your plant’s pH need.

Moisture meter
You can use a soil moisture meter to measure the moisture and pH of the plant soil.

Solutions

  • Introduce organic matter into the soil by amending it with organic compost such as worm casting, bone meal, fish meal, etc.
  • Amend the potting soil with sphagnum moss or coffee grounds to drastically lower the pH level.
  • Alternatively, add elemental sulfur, iron sulfate, or aluminum sulfate, which often come in soil amenders or fertilizers, into the soil.
  • Transplant the plant into a fresh potting mix amended with organic compost or other organic matter.
  • Use a soil pH meter kit annually to check the soil’s acidity level or when transplanting in a fresh potting mix.

7. Poor Water Quality

Using poor quality water for houseplants will invite many different problems, sometimes leaf bleaching.

By poor quality water, we meant water rich in hard minerals such as chlorine, fluorine, chloramines, and other bicarbonates.

Regularly watering the plant with this type of water will lead to mineral buildup in the soil. Any mineral buildup is terrible as it prevents roots from absorbing nutrients and oxygen.

One of the earliest indicators is water stains on the plants and wilting.

Although unusual, some plant leaves will witness bleaching or whitening with chalky calcium deposits.

Therefore, experts advise avoiding using hard water such as tap or mineral water for watering the houseplants.

Solutions

  • Consider wiping the chalky deposit on leaves with an acidic mixture like lemon water or vinegar water.
  • Consider transplanting it in a fresh potting mix for severely damaged plants immediately.
  • Use collected rainwater, snow melts, and filtered and distilled water for indoor houseplants.
  • As a preventive measure, avoid using mineral or tap water in the future.

8. Pest Infestation

Although rare, the houseplant infected with pests such as mealybugs and spider mites may witness white sticky substances on the leaves.

Many sap-sucking insects feed on the plant leaves, leading to visible damages such as spots, holes, boils, and white substances.

Different pests in plants
Pest sucks out plants’ nutrients and leaves behind brown and white spots on leaves.

Mealybugs and spider mites are a few common pests that may invade your houseplant.

MealbugsSpider Mites
Mealybugs are wingless insects that appear as white cottony masses on leaves.Small spider like insects will reside on the undersides of leaves where they spin protective silk webs.
They suck sap and release a white sticky substance over the leaves, resembling cotton.Entire leaves get covered in webs of spiders and pale shiny yellow or white marks will appear.
Spider Mite

Houseplants are prone to different pests’ infestations like scales, whiteflies, aphids, and bugs.

However, mealybugs and spider mites are more likely to build white-looking substances on the plant leaves.

Solutions

  • Start with quarantining and dispose of the heavily infested plant.
  • For less damaged plants, pick the visible insects from them and drop them in a soapy water solution.
  • Rub isopropyl alcohol into the affected regions using a cotton ball dipped into the solution.
  • Spraying or rubbing neem oil on the infected part will help treat the infection.
  • Washing the plant with insecticidal soap will also help treat pest infestation.
  • Alternatively, you could use Garden Safe and Ortho Max as chemical options (Follow the manufacturer’s guidelines before applying).

Related Article: How to Identify Insect Eggs on Leaves and Treat Pest Infestation?

9. Plant Diseases

Along with Powdery mildew, some other diseases may also cause white spots on the houseplants.

Ringpsots caused by Neopseudocercosporella capsellae and downy mildew may introduce fungus to plants.

Also known as white leaf spots, ring spots usually appear as a white circle on the leaf when there is too much humidity with warmer temperatures.

On the other hand, downy mildew may appear in cool, humid environments. Several fungus-like organisms Oomycota may wilt the leaves causing white, gray, or bluish patches to appear.

White spots on leaves
Downy mildew leaves small white spots on the foliage.

Solutions

  • Start quarantining the plant to prevent further diseases from spreading to other plants and dispose of badly affected plants.
  • Apply neem oil on the infected parts to treat fungus infestations and repeat the process every week until the problem subsides.
  • Trim off infected leaves and dispose of them safely.
  • Apply fungicides that contain Chlorothalonil and mancozeb to treat downy mildew and benzimidazole fungicide to eliminate ringspot.

Should I Cut Off the white Leaves on Plants?

When your plant is covered with many whitening leaves, the best option will be to remove them immediately.

Removing the white leaves would help redirect the plant’s energy toward new and healthy growth.

However, not all white leaves have to go. It will depend on the severity of the problem.

  • Powdery mildew can be cleared off the leaves without trimming them, and so does most watering problems.
  • Consider immediate removal of badly scalded and pest-infested leaves, which may do more bad than good.
  • Care to sterilize the pruning shear or scissor using 98% isopropyl alcohol before and after use to prevent fungal infestation.
  • Remove white leaves and remove yellowed or browned leaves and leggy growth.
  • Leaves with a few white spots or discolored edges may turn green again, requiring no pruning.

How to Prevent White Leaves on Plants?

Remember, a healthy plant grown in healthy condition is less likely to attract problems.

Therefore, you should ensure to keep the plant’s surrounding healthy and kempt all the time.

Here are some proven tips to prevent white spots on leaves.

  • Start with scheduling watering for each plant in the growing season (spring and summer) and dormancy (fall and winter).
  • Avoid both over and under-watering to prevent the plant from going into stress.
  • Choose the plant location carefully, east or south-facing window and near or a few feet away from the direct light source.
  • Understand each plant’s nutrient requirement and fertilize regularly using the liquid or granular solution.
  • Install room air humidifier to maintain optimal humidity level for indoor plants.
  • Ensure the temperature stays between 50 to 80 degrees Fahrenheit, depending on its nature.
  • Keep your plants cleaner during spring and summer with neem oil, horticultural oil, or a soapy water solution.
  • Trim the bushier, decayed, and old growth in the growing season to allow better air circulation, preventing the risk of pests and diseases.
  • Assess the soil pH level once yearly and amend the soil with compost or fresh soil mix as necessary.
Cucumber leaves white spots
Look out for tell-tale signs of white spots on the leaves, which may look ghastly and unappealing.

Conclusion

Treating whitening leaves on plants may sound challenging when you have grown different species at home.

Instead of looking for quick fixes, consider applying preventive measures to remove the risk of white leaves altogether.

Otherwise, follow this guide to diagnose the problem and effectively treat white leaves on your plant.

Please drop in your comment to let us know whether you faced a whitening leaf problem and the treatments you applied.

Related Article: How to Treat White Spots on Cucumber Leaves?

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