Brown spots on the leaves of your Chinese evergreen are one of your plant’s unique ways of revealing an underlying problem. Most issues associated with brown spots on leaves are related to either overly dry or waterlogged soil, or to dry air.
However, there are also other external factors that might also cause leaf discoloration. This guide aims to help you diagnose this problem in your Chinese evergreen and implement the right solutions to bring back your plant’s vigor.
Common causes of brown spots on Chinese evergreen
1. Too much water
Overwatering is a common mistake among plant owners generally, and you could also make this mistake when you see your plants in distress and (wrongly) assume that it needs more water. Brown spots, for example, might lead you to think that your plant is thirsty, when it is actually drowning and suffocating from too much water. As the experts say – overwatering is the easiest way to kill your plants.
Chinese evergreens, like most houseplants, need their soil just damp enough to keep them hydrated. Allowing them to sit in waterlogged soil for prolonged periods cuts off the flow of oxygen to the roots, which will eventually cause the roots to die and start to rot. And, without healthy roots, it is impossible for your plant to absorb the water and nutrients it needs to stay alive.
Wilting leaves with brown spots are probably the most obvious signs of a drowning plant, but if you remove it from its pot, you will also see that the roots have become dark and mushy instead of being white and firm.
This condition is not always caused by straightforward overwatering. Other factors can also contribute to root rot, including densely-packed soil, pots without sufficient drainage holes, and pots that are too large for the plant. All of these factors prevent excess water from draining efficiently, resulting in standing water around the plant’s roots. Continually wet soil, whatever the reason, will decay the roots and the rot will soon spread throughout the plant. The wet conditions are also an ideal breeding ground for fungi, which can further exacerbate the problem.
2. Not enough water
Are you often forgetful about watering your plant because of your busy schedule? Then you may already be familiar with the unfortunate outcome of neglecting a Chinese evergreen for too long. As the soil becomes too dry, the plant’s roots become severely damaged due to dehydration. The ill effects manifest as pale, sad-looking foliage with brown spots all over.
We have mentioned how harmful overwatering is to our Chinese evergreen plants, but so is underwatering. If you are a novice gardener, this might leave you baffled as to exactly how much water is sufficient to keep your Chinese evergreen in top shape. Unfortunately, there are no specific rules that dictate how much water your plant needs, because the frequency and amount of water will depend on factors like the season, your local climate, and the current weather conditions.
The finger test is probably the easiest way to determine when your plant needs water. This is done by using your finger to feel the dampness of the topsoil, down to about an inch or two deep. If the soil feels dry, it is time to water your plant. Another method is to invest in a soil moisture meter, which will more accurately monitor the moisture content of your soil in real-time.
The best practice when watering your Chinese evergreen is to water it enough that you can see excess water flowing out from the pot’s drainage holes. Be consistent about your watering, as irregularity is not good for the plant’s health.
3. Low humidity
Low humidity levels can compromise the health of your Chinese evergreen. Dry air can cause several problems in houseplants, including root and foliar diseases, plant stress, leaf discolorations, and falling leaves. You might also notice the leaves becoming brown and dry due to the lack of moisture in the environment.
Unfortunately, it can be very difficult to control humidity, even in a greenhouse, because it fluctuates with the changes in air temperature. And the drier the air, the faster the plant’s transpiration rate.
Chinese evergreens need about 60 to 70 percent humidity for proper growth and healthy foliage. To achieve this humidity level, you may need to mist the plant regularly or – even better – use a humidifier in the room.
4. Nutrient deficiency
A lack of soil nutrients is another problem you might encounter with your Chinese evergreen. You can tell that your plant is nutrient deficient when it produces deformed leaves with kinked edges, yellow or brown leaf edges, or brown spots on its leaves.
Houseplants all need roughly the same essential macronutrients and micronutrients for healthy growth, and an absence of any of these nutrients can cause various growth problems and diseases.
Some common reasons for nutrient deficiencies in plants are as follows:
- Poor quality soil
- Inadequate fertilizer
- Plant has not been repotted for too long
5. Using tap water with harsh minerals
Using tap water for your plant is not a good idea, because it contains harsh elements that can damage the plant. These include fluorine, lead, chlorine, and bicarbonates, all of which are proven to harm houseplants.
Filtered water is the ideal for houseplants because it is free of impurities and minerals. Although having a home filtration system is the best way to go, there are other, cheaper ways to make tap water safe for your plants.
The most common method is to fill a bucket with tap water and let it sit overnight. This allows most of the elements like chlorine to dissipate naturally.
Carbon-type filters also work well for filtering hard water. However, it is not advisable to use water that comes from a household softener; it is known that the salt in softeners can damage plants.
Another cheap and safe source of water is rainwater. Simply collect the water in buckets when it rains and store it until you need it.
6. Plant stress
Houseplants like Chinese evergreens can suffer stress from various external factors. Although it might not kill your plant right away, continued stress can contribute to a reduced quality of foliage, browning leaves, stunted growth, and decaying roots. Thus, it is important to understand plant stress so that you can grow your Chinese evergreen optimally and prevent unsightly discolorations.
Some common stressors in plants are:
- Repotting or transplanting
- New environment
- Extreme temperature fluctuations and cold drafts
- Soil compaction
- Inappropriate soil pH
- Soil toxicity
Chinese evergreens are happiest when exposed to indirect sunlight. For this reason, they are best grown indoors, and leaving your plant outside under full sunlight can burn the leaves and turn them brown.
Chinese evergreens are native to tropical rainforests, where they thrive under the tree canopy in filtered sunlight. Exposing your plant to indirect sunlight for two to three hours a day should be sufficient to foster proper growth. If you do not have access to indirect sunlight, you can resort to artificial lighting to keep your plants healthy and growing.
8. Pest infestation
Pest infestation is another possible reason your Chinese evergreen’s leaves have developed brown spots. These tiny creatures suck the sap from your plant’s leaves and inject salivary fluids that can kill portions of the leaf. Sucking insects excrete sticky substances that promote the growth of sooty mold and attract ants. Some insects also breed and lay their eggs on the leaves, exacerbating the damage.
If your Chinese evergreen is struggling with a pest infestation, you can use one of the solutions below to bring your plant back to life:
- Clean the leaves with horticultural soap
- Spray neem oil on the affected parts to get rid of the pests
- Mix equal parts water and rubbing alcohol, and use mixture this to remove the pests from the leaves and stems
Can Chinese evergreens recover from brown spots?
The good news is that your Chinese evergreen should bounce back to health quite easily with the right care and preventative measures. If you see brown spots on its leaves, identify the cause, prune the affected leaves, and begin correcting the problem. Keep in mind that the most common causes of brown spots are inappropriate watering and lack of humidity, so make sure to check those first.
Additionally, the color of the soil’s surface alone might not tell you the whole story. As mentioned, it is recommended to use a moisture meter device to keep track of your plant’s moisture needs, or at least use the finger method to determine whether you have dry or waterlogged soil.
Wrapping it up
One of the reasons that Chinese evergreens are so popular is that they are very low maintenance – a novice grower should find this beautiful plant easy to care for with minimal effort. However, this does not mean that long-term neglect and inappropriate care will not harm your plant eventually.
Brown spots on the leaves of your Chinese evergreen are an obvious sign that your plant is now well and needs a bit more attention. You will need to identify the problem in order to address it correctly and, provided you act in time, your plant should bounce back to health very soon.
Image: istockphoto.com / Adehan Ahmad