Begonias are beautiful houseplants from the Begoniaceae family. They bring new life to the dull and dark corners of a house. I have my begonia plant on my office desk. This plant is easy to care for because it does not need much maintenance. But begonia leaves turning brown is a common problem in all varieties of begonias.

This is an alarming situation you need to take quick action to solve the issue. Or you will lose a beautiful foliage plant.

Overwatering, underwatering, nutrient deficiencies, low humidity, and pest infestation result in begonia leaves turning brown. All these problems have simple solutions. First of all, you need to identify the cause then follow the solution given in this post. 

Because in this article, I will cover all the possible causes that can cause brown crispy leaves in begonia with their solutions.

Watering is the main cause that turns beautiful begonia leaves into brown color. Underwatered begonia loses the water stored in the leaves. Due to lack of water, the begonia leaves turn into brown color.

To avoid this condition, you need to learn the best watering methods.

Begonias need moist soil but they do not want soggy soil. Therefore, try to avoid overwatering because overwatering results in soggy soil.

Then the soil becomes unable to circulate fresh oxygen and due to lack of fresh air plant roots start rotting.

Root fungus completely destroys the up-taking system of the plant and the plant becomes water-deficient and nutrient deficient. Both these conditions turn green begonia leaves into yellow and brown crispy colors.

How to water dehydrated begonias?

To water begonias, you need to check the soil conditions. If the soil has good moisture, then wait until the top 2 inches get dry.  Then give water from the top without wetting the plant leaves. This should be your regular watering routine.

To water dehydrated begonia you need to immediately give moisture to plant roots. For that reason, bottom watering is the best option.

First of all, fill the sink with water and then put the plant in a water-filled sink without the bottom tray (saucer). When water touches the bottom hole, the soil immediately starts absorbing water. This way the water quickly reaches the plant roots. After 5 minutes take the pot out of the sink and check the top few inches of the soil.

If the top few inches are dry then give some water from the top. Your plant will shortly produce new beautiful fresh leaves.

But here you need to cut the brown crispy parts of the leaves to encourage new growth. Old brown leaves will not turn green again at any cost. Brown leaves mean that part of the plant leaves is dead. They are also called dead leaves.

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Low humidity causes brown leaves in begonias

Begonia needs room humidity above 45%. If it drops below, they feel uncomfortable and their leaves start losing moisture.

This means you need to keep eye on the room humidity. You can do so with the help of a Hygrometer. This is the device that is used to monitor the humidity of a place.

Set the minimum percentage of air moisture and it will trigger an alarm when it drops below the set value.

To increase the room humidity,

Firstly, you should adapt traditional methods like grouping the plants. In this method, you put all your plant pots in a single place. This creates a humidity bubble around the plants and increases the actual room humidity.

The second method is using a humidity tray. Fill the tray with fresh water and add small pebbles. Then place your plant in it. Make sure the water level remains below the bottom draining hole of the plant pot.  Or the soil will absorb the tray water and this causes overwatering issues.

The last and most effective option is using electric plant humidifiers. They are specially designed for plants and are less expensive than regular room humidifiers.

begonia leaves problems

High intense sunlight

Begonias are native to tropical jungles. This means they do not need high-intensity light. The direct sun rays are highly intense and sharp. When you expose your plant to direct sun rays. They damage the plant tissues and this causes brown spots on begonia leaves.

The first sign of sunburn is brown leaf tips because they are the softest part of the plant. Once you see the brown tips immediately change the location of your begonia plant.

Begonia leaves turning brown and crispy due to extremely bright light is a rare condition.

To prevent light burn place your begonia in indirect bright light. Or install a curtain on a sunny window to filter the direct light.

Low temperature

Begonia is a tropical plant so it needs warm weather to grow. But it can also tolerate a little bit of cold. Maintain the room temperature above 60 degrees F for the good health of begonia leaves.

Begonia leaf problems start when the temperature drops below 55 degrees F.

Because the cold temperature directly damages the begonia leaf cells. When they get damaged the plant becomes unable to synthesize properly. The leaves absorb light energy in a low amount and result in unbalanced photosynthesis.

To avoid temperature-related problems in begonia plants. Move them to a warm place in the winter months. Also, install a room temperature monitor device and make records of temperature.

This way you will know when the room becomes cold and the plant starts to suffer.

Begonia plant diseases cause browning of leaves

If everything is perfect, all the growing requirements are complete. Then the brown begonia leaves problem may be because of pests and diseases.

Pests like aphids and mealybugs suck the plant juice. The plants lose their stored glucose and have no food left to grow. This is the number 1 reason for plant deaths in the USA.

These pests are small in size and often found on unhygienic begonias. Pests are commonly found on the undersides of the leaves. Check the leaves carefully and if you see the signs of pest infestation. Immediately pour some rubbing alcohol on cotton and wipe both sides of the leaves.

The rubbing alcohol will kill the pests and also their colonies and eggs.

Note: The use of rubbing alcohol on plants is 100% safe and has no negative effects in any form.

For serve infection, wash your plant with insecticidal soap. You will not need to use commercial pest control sprays. Because begonias are small and soft foliage plants. They will not tolerate the harsh chemicals of commercial pesticidal sprays.

begonia spotted leaves

Root fungus

Root rot results in begonia leaves turning brown and crispy if not fixed on time. The fungus developed in the plant pot starts destroying the root ball.

Yellow leaves, wilting and weak plants are the few early signs of root problems. You will also smell an unpleasant scent from the base of the plant due to root infection.

How to solve root rot in begonias?

Follow the below steps to save your plants.

  • Lose the soil and gently take out the plant from its pot.
  • Remove the soil from the roots with hands or cotton.
  • You will see the damaged part of the roots.
  • Take the sterilized shears and cut the infected parts.
  • At a time, you can cut 40% of the roots.
  • Then throw the soil and wash the plant pot with soap and dry it.
  • Now put new soil in the plant pot and plant your begonia in it
  • Do not give water for 24 hours after that you can start slowly
  • Put the plant in bright light and give some water.
  • Your plant will show signs of weakness and will recover in 7 days.

Fertilizing mistakes

Accidental excessive use of fertilizers causes browning of begonia leaves. Begonia only needs light liquid fertilizers only a few times per year.

Nutrient supplements are only required to boost plant health not to speed up growth.

Anything excessive is deadly for plants.

Therefore, fertilize your begonia only in their active season (spring and summer). Stop fertilizing on winter days.

How to recover overfertilized begonia?

  • Take the plant out of its pot.
  • Remove the soil from the root ball
  • Place the plant on the newspaper
  • Now take the pot near the water tap and rinse the soil.
  • Let the tap ON for 10 minutes or until you see clear water coming out the bottom hole.
  • Then close the tap and let the pot in the sink for 15 minutes to drain the extra water.
  • Then plant your begonia back in the same pot in the same soil.
  • You should complete this entire process in less than 60 minutes.

NOTE: To make the soil dry you can take it out of the pot and spread it over the newspaper. This way the soil will get dry quickly and you save time.

This is all about the begonia brown leaves and their solutions. If you have more questions or your begonia is in another problem. You can write us and send us images of your plant. We will reply ASAP.