Brown Spots on Dracaena Leaves (Causes and Treatment)

Dracaena is one of the favorite foliage plants both for indoor and outdoor settings. Its varying shades of green, painted with stripes of white, yellow, or cream, make the plant highly attractive.

That’s why seeing brown spots appearing on the leaves is a huge disappointment. You’re on the right page if you’re having trouble with the same problem. 

Dracaena leaves develop brown spots because of poor growing conditions such as excess light, temperature stress, humidity, and poor air circulation. Some biotic stresses caused by pest infestation, bacterial leaf spots, fusarium leaf spots, and rust also lead to the same problem.

To know how each cause affects your plant, keep reading and learning the important facts you must remember to treat the brown spot problem.

How to Identify Dracaena Brown Spots

Brown spots appear differently in dracaena leaves. Depending on the agent that causes the brown spots, it will vary in its degree of brownness, size of the spots, and its location in the leaves. 

Some brown spots appear on the young leaves while others can be found on the mature leaves alone. Brown spots may also appear on the margins of each leaf or at the tips. 

There are tiny brown spots while there are those that enlarge over time. Some spots are water-soaked.

The colors of the spots may range from being light brown to reddish-brown to brown-black. 

What Causes Brown Spots on Dracaena Leaves? 

There are several possible reasons why brown spots appear on the leaves of your dracaena.

Most of them are triggered by stresses that are caused by poor environmental conditions and some are due to wrong practices. 

The following are the most common reasons why brown spots develop in the leaves of your beloved dracaena:

Excess Light

Light carries in it an amount of energy used by plants in photosynthesis, an important metabolic process.

The varying light levels also affect the appearance of the dracaena plants, especially the ones with variegation. 

With so much exposure to light, the excess energy harnessed can possibly stay in the plant cells. (Sources: Science Daily)

It will then produce reactive oxygen species that will easily react with the molecules inside the cells. This leads to damage and death of the plant cells. 

How to Treat:

Dracaena needs bright but indirect light. If its current location is receiving intense light, remove it there and place it somewhere shaded. Different varieties require different shade levels. 

If no other location is suitable, just put a sheer curtain in between the window and the plant to add protection. 

Temperature Stress

Extreme changes in temperatures cause stress in plants. The ideal temperature range for dracaena is between 65 and 90°F (18 to 32°C).

If the temperature rises above the limit, the plant will develop iron chlorosis. 

Likewise, exposure to cold temperatures of 35°F will cause serious damage. Prolonged exposure to 55°F temperature will also do the same.

Abrupt and sustained unfavorable temperature conditions can damage certain cell parts and functions. 

How to Treat: 

If you’ve noticed that the plants are responding negatively to the changes in temperature, find ways to lessen the impact of the stress.

If it’s too hot, use a cooling fan or air-condition to lower the temperature. Misting will also help alleviate the hotness. 

When it’s too cold, insulation will help add warmth to the plant. It will protect the dracaena from frost damage as well.  

Humidity

Dracaena plants need high humidity for the best growth. If you’re keeping it in a place that’s too dry, then it must be the reason why brown spots appear in its leaves.

Inadequate humidity will lead the plant to easily lose water and leaves curl.

This article discusses all the possible causes and solution of dracaena leaves curling.

How to Treat:

Mist around your dracaena every morning especially when the air is too dry.

Morning is the best time to mist because we want the excess moisture to evaporate before the night time comes.

This will prevent the growth of disease-causing pathogens. You may also set up pebble trays under your tropical plants including dracaena.

The water in the tray will help increase the moisture in the air around your plant.

Poor Air Circulation

Plants also need fresh air just like humans do. When your dracaena gets stuck in a poorly ventilated room, it will encounter trouble.

One is, if the room is damp, the lack of airflow will contain that dampness for a prolonged period. 

We know that a damp environment invites a lot of diseases. Pathogens grow and multiply when this condition is permitted. 

Solution

Open the windows to allow air to flow. If you have an exhaust fan, turn it on so that the suspended air can get flowing.

Space out your plants from one another so that they have enough breathing room. 

Pruning your plants is also a good way to lessen the overcrowding. That way, more air will penetrate into the spaces.

Pest Infestation

Fungus gnats, mealybugs, scales, and thrips are the possible pests that can harm your dracaena and ruin its foliage.

These organisms feed on the sap of the plant tissue by sucking them. As a result, they leave lesions that look like tiny brown spots. 

Light infestation is normally tolerable. Your dracaena will continue to live even with the presence of these organisms. However, if they get out of control, they can be a real pain.

Solution

Manually remove the pests once seen. Eliminate the leaves and stems that are heavily infested. Wash them off using a strong water flow.  

If they continue to persist, spray horticultural oils or insecticidal soap diluted in water. You may also wipe them off using cotton dipped in alcohol. 

Bacterial Leaf Spot Disease

Bacterial leaf spot in foliage plants such as dracaena is caused by bacteria belonging to the genera Erwinia, Xanthomonas, and Pseudomonas.

This disease creates lesions on the leaves of the plant. Some spots are black, yellow, or reddish-brown depending on the type of bacteria that’s present. 

How to Treat:

Immediately pinch off and discard leaves and stems infected with bacterial leaf spots. The earlier you notice the problem, the better. 

Keep the foliage of the plant dry as much as possible. Water the plant in the morning so that there’s enough time for water to evaporate. 

Fusarium Leaf Spot Disease

This disease creates water-soaked spots on the young leaves of dracaena.

The spots tend to enlarge through time, become red or tan in color, and are circled by a yellow halo. Infected leaves can die if severely damaged. 

Fusarium leaf spot is caused by a pathogen named F. moniliforme. The dracaena species that are most susceptible to fusarium leaf spots are the D. marginata, D. marginata ‘Magenta’, D. reflexa ‘Song of Jamaica’ (Pleomele reflexa). (Source: University of Florida/IFAS)

How to Treat:

Eliminate the infected portions of the plant to prevent the spread of diseases. Space out your plants and if possible, isolate your dracaena from the others.

Make sure that there’s enough air circulation and that the foliage is dry most of the time. 

Apply fungicides such as Daconil, mancozeb, or benomyl on the nearby dracaena plants as a preventive measure. 

Rust

Rust can appear as red, orange, yellow, or brown spots located on the inner and lower leaves of the dracaena plant.

It’s a result of a fungal disease that might have infected the plant causing the unpleasant appearance.

When spores of rust are transferred to the plant, they will start spreading to the leaves.

They consume the tissues of the plants in order to live. The presence of rust is not serious harm unless their population gets beyond control. 

How to Treat:

Always check the underside of the leaves and observe for any presence of rust. Prune the infected leaves and discard them properly.

Ensure ample space in between plants to allow good air circulation and reduce moisture levels around the plant.

The growth of pathogens will slow down when the environment is no longer favorable. 

Fertilizer Problem

One of the common culprits why many plants develop brown spots is the overapplication of fertilizers.

Fertilizers are good but only to some extent. If you’re overdoing it, your dracaena plant will suffer.

Fertilizers contain salts that usually build up in the soil through time. These salts will draw away water from the roots of your plant, creating a drought condition. The roots will shrivel because of dehydration.

The damage caused by fertilizers on the roots will impair their function. It will hamper the roots’ ability to transport water and other nutrients up to the plant’s other parts. 

How to Treat:

If the leaves of your dracaena plant start showing brown spots on its tips and margins after you’ve applied fertilizer, leach it off with water. Application of 6” water will remove 50% of the salts from the soil. 

Check the roots to assess if there are serious injuries. If none, you can leave the plant in its pot until it fully recovers. Just withhold the application of fertilizers to allow the roots to heal. 

As a tip, add fertilizers only when the plant needs it. If your dracaena looks vibrant and healthy, then skip fertilizer application. 

Inconsistent Watering

Another reason for the brown spots that appear in dracaena leaves, especially at the tips is inconsistent watering.

This inconsistency can lead to two problems: overwatering or underwatering. 

Overwatering will cause the roots to rot while underwatering will lead to shriveling of the whole plant. Both phenomena show the browning of leaves as a sign. And eventually, your dracaena leave can fall off.

How to Treat:

If the dracaena plant is underwatered, water it immediately. Water the soil deeply and evenly until it’s saturated. Once the plant is quenched, it will return to its turgid appearance. 

For overwatered plants, it’s best to withhold water for several days. Check the roots and see how far the injury has spread. Then Repot if needed.

Water Quality

Another factor that can lead to the development of brown spots is using poor quality water.

Some water supplies contain high soluble salts that can damage the roots.

These salts can also accumulate in the leaf margins of the dracaena leading to tip burns.

The cultivars “Warneckii”, “Janet Craig” and “Massangeana” are particularly prone to fluoride toxicity.

If the water you’re using water that contains 1 ppm of fluoride, these cultivars will most likely develop browning in their leaves. 

How to Treat:

Use filtered water if you have a filtration system at home. It helps remove particles and contaminants in the water.

If not available, allow tap water to sit for at least 24 hours to allow the chlorine and fluorine to evaporate. 

As much as possible, save rainwater during the rainy days. It still is the best option for your indoor plants such as dracaena.

How Do You Treat Brown Spots on Dracaena?

Although the problem of brown spots on foliage plants may seem overwhelming, there are always ways in which you can save your plant from the perils.

Here are practical ways to treat brown spots on your dracaena plant.

• Diagnose the real problem. Brown spots are just signs of an inner problem. You must learn how to observe and assess the condition of your plant in order to know what exactly the source of that problem is. 

• Eliminate the leaves that are heavily infected with brown spots. To prevent the spread of diseases, better remove infected leaves once noticed. If the brown spots are not caused by pathogens, you may keep them intact as there’s no danger of spreading the disease. 

• Stop creating a prolonged damp condition. Diseases are most likely to develop when your plant is consistently damp. Let it dry throughout the day by watering only in the morning and by providing good airflow.

Schedule your misting in the morning as well to give time for the excess moisture to evaporate.

• Provide proper lighting. Place your plant in a location with low to medium light. Shade is necessary to avoid leaf scorch. Avoid exposing your dracaena to direct sunlight especially if the intensity is too high. 

• Use good quality water on your plants. Dracaena is highly sensitive to fluorine so make sure to use the filtered one. If not, use rainwater.

Let water drain well from the pot to avoid root rot. Adjust the volume of water depending on the temperature, humidity, and light conditions.

• Apply fertilizer only when needed. Overfertilization is a big enemy of indoor plants. It can instantly kill your dracaena especially if given in high amounts. Remember to dilute fertilizers when used in potted plants. 

Opt for organic fertilizers as a more sustainable option. There are a lot of readily available environment-friendly fertilizers you’ll find in the market. 

• Provide good ventilation. Let the air flow in and out of your home. That way, all the particles, contaminants, and even spores of pathogens in the air don’t remain within the vicinity.

Good ventilation will also help ease the dampness around your plants. Prolonged moist conditions are never good for dracaena.

• Use horticultural oils and insecticidal soap on pests. Most harmful organisms found on indoor plants can be managed by these DIY solutions. No need to apply chemical pesticides. 

It’s recommended that you check on your dracaena regularly to check for any presence of pests. Don’t wait for these organisms to feast on the plant before you notice them. 

• Keep your plant away from drafts. Air conditioners, fireplaces, and cold windows are some locations where you should avoid placing your dracaena. These drafts release extreme temperatures that may stress the plant.

• Use sterilized soil. Disease-causing pathogens are mostly found in soils. They stay there for too long until they find a suitable host. 

If you’re using unsterilized soil, there’s a high chance that your plant will acquire a disease caused by the pathogen present in the potting mix.

You may buy sterilized potting mixes from garden stores or you may create your own.

• Protect your plant from the frost. Dracaena is not frost tolerant. It can easily get damaged by cold temperatures. When you observe that the environment is getting colder and colder, provide insulation on your plant. 

• Keep the humidity high. Dracaena requires high humidity to grow well. Otherwise, it will easily lose moisture and get dehydrated. When plants are always thirsty, they will lose their vigor and turgidity. 

Take good care of your dracaena’s leaves, as they are the plant’s main attraction. Be observant of brown spots and try to identify the cause.

Provide prompt treatment and monitor the plant’s response. Your dracaena’s life is in your hands, so do your best to care for it.

Here is how to transform your Dracaena Marginata into a one-of-a-kind masterpiece with my guide on caring, bending, and shaping techniques. Don’t miss out; read it now!

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