Witnessing large green Dieffenbachia leaves marked with stripes, dots and colored veins turning yellow untimely, especially during active growing seasons, can sadden anyone.
Therefore, pay attention to the sudden yellowing of Dieffenbachia leaves and treat it early before it turns unmanageable.
Table of Contents Show
Is Dieffenbachia Yellowing Leaves Natural?
Some yellowing of foliage in Dieffenbachia is natural if the plant is aging or a variegated type.
You can tell it is the natural discoloration when the new growth on the top is unfazed, but the bottom leaves are yellowing.
Like any other plant, Dieffenbachia will shed its old leaves to encourage new ones by sending energy toward new growth.
Therefore, seeing yellowing and dropping bottom leaves is usual in summer when the plant is vigorously growing.
Cut them off using a sanitized pruning shear to help your plant channel energy toward new growth.
Other than aging, yellowing and dropping leaves hit an alarming bell!
What Causes Yellow Leaves on Dieffenbachia? (Reasons+ Solutions)
Also known as Dumb Cane, Dieffenbachia is a tropical flowering plant from Mexico and South America that thrives in a warm and humid climate.
It does well indoors in lots of indirect light, with warm temperatures, regular watering, fertilization, and ample humidity.
If any of the above factors goes awry, your Dieffenbachia plant leaves will begin changing color.
1. Water Stress
Often caused by overwatering, water stress is the main reason behind yellowing leaves.
It occurs when excessive watering keeps the potting soil wetter for an extended period, causing the heavy-looking pot and soggy soil.
The waterlogged soil will drown the plant roots, resulting in reduced airflow (oxygen) and nutrients to the roots.
Without an exchange of ample oxygen and nutrients, your Dieffenbachia leaves will succumb to distress and start changing color.
Therefore, be wary of the water stress risk in spring and summer, when the plant usually needs a heavy water intake.
Similarly, the poor draining soil will also lead to water stress problems, which is often seen with the wrong or older potting soil.
- Start with drying the potting soil by cutting back on watering.
- Identify any root rot problem by sliding out the plant and prune the infected ones.
- Put the pot out in the sun to dry before replanting it.
- Otherwise, consider replacing the old soil with a well-draining substrate.
- Once replanted, set it in a warm location with indirect sunlight and water only when the yellowing decreases.
- As a preventive measure, water your plant only once a week by thoroughly soaking it and removing excess water from the drip pan.
2. Drought Condition
Drought conditions often instigated by underwatering and extreme temperatures may also lead to chlorosis in the Dieffenbachia plant.
The drying out of the soil will choke the roots of oxygen and nutrients, gradually killing them.
Similarly, the topsoil will also look lighter and cracked when severely underwatered.
On the other hand, extreme temperatures, ranging above 90°F, will dry out the soil and lead to leaf transpiration (loss of water).
You would notice yellowed and crispy leaves, sometimes accompanied by the browning of the tip and edges.
- Start pruning off excessively yellowed, crispy, and browned leaves to channel the energy toward healthy growth.
- Dieffenbachia is pretty resilient, so resume watering to fix drought conditions quickly.
- Thoroughly water the pot and let it sit until the soil has soaked before removing the excess water from the drip pan.
- Alternatively, you can submerge the pot in a water container for half an hour to allow the soil to soak naturally.
- Approach bottom watering to allow the plants to drink from the bottom for up to 24 hours, along with watering over the soil.
3. Temperature Stress
Dieffenbachia is a tropical plant thriving in a warm, humid climate with temperatures between 60-80°F.
Therefore, the drop in temperature may not fare well with Dieffenbachia leaves, where it will begin witnessing yellow, drooping leaves.
It is more commonly seen with plants grown in the garden or a container kept outside.
Those grown near the draft window during fall and winter or below the air conditioner may also witness cold stress.
- Immediately move your plant indoors and place them under LED growing light.
- Place the heating mat under the pot or use plastic insulation to induce heat around the plant to avoid further cold damage.
- Prune off severely yellowed and droopy leaves to conserve the plant’s energy for the coming days.
- As a preventive measure, keep a digital thermometer beside the plant pot to check if the temperature drops below 55°F.
It may take 2-3 weeks before the cold-stressed plant can recover fully.
4. Extreme Light
Dieffenbachia leaves exposed to direct sunlight for a longer duration will witness bleached leaves or sun scalding.
Similarly, some yellowing with browning tips is the common determinant of the extreme lighting problem.
Therefore, they will grow best in a location with indirect or diffused sunlight received for 6-8 hours a day.
- Move your plant from under the direct light source to an area with diffused sunlight, such as a shaded patio, window, or doorway.
- Start with removing overtly damaged foliage with excessive yellowing, bleaching, or browning.
- Provide a medium to bright light, usually found in the east-facing window, with about 2 hours of early sunlight.
- When placing it at the south-facing window, keep it at least 3 feet away.
Move it to a bright, warm spot around the house in fall and winter, where it can rest throughout dormancy.
5. Low Humidity
The drop in humidity level would often lead to transpiration, leaving the foliage dry and yellowed.
You would mostly witness the top of the leaves yellowing and wilting and gradually browning with a crispy texture.
Likewise, the browning and crispy texture also highlight the issue with low humidity and extreme temperature.
Your plant is more likely to experience humidity stress when moved from high humid area to a low one, like moving from a nursery or greenhouse to your home.
- Start with removing severely damaged leaves to redirect energy towards healthy growth.
- Gather your houseplants together to boost the humidity level in the air naturally.
- Otherwise, install a room humidifier to boost the humidity level to the desired level.
- Moving the plant to humid areas like the kitchen or bathroom may also help.
- Mist your plant leaves using a plant mister during the hot or summer days to keep the leaves moist.
6. Malnutrition Problem
The malnourished plant usually exhibits discolored foliage, lanky stem growth, and smaller leaves.
Some other signs of nutrient deficiency in Dieffenbachia include:
- Interveinal yellowing of foliage
- Shortened internodes
- Unusual coloration (red, purple, or bronze)
You would witness yellowed foliage in a plant that has not been fertilized in a while or has not been repotted for years.
Similarly, the plants grown in soil substrates like peat moss and perlite would require frequent fertilizing to boost the number of microorganisms.
- Start fertilizing your plant with a complete 20-20-20 formula and repeat the process every 3-4 weeks.
- When using a water-soluble fertilizer, ensure to dilute it to half-strength by mixing it with water.
- Alternatively, you can use organic and homemade fertilizers rich in macro and micronutrients.
7. Pests and Diseases
The most significant drawbacks of growing tropical plants at home are pests and diseases.
Dieffenbachia is no different as it attracts many kinds of sap-sucking bugs like scale, mealy bugs, and spider mites.
These sap-sucking insects would feed on leaves and stems, leaving them weak and discolored, so the yellowed leaves with small holes and brown edges may indicate infestation.
Similarly, the faulty growing condition may push the tropical plant to an extreme, often leading to fungal and bacterial infestation.
Bacterial leaf spots and wilt are common in the Dieffenbachia plant, generally caused by the Erwinia carotovora pathogen or severe drought.
You will also witness dark left spots, yellowed or tanned spots, and yellowing lower leaves.
Besides, rot invited by overwatering may lead to fungal infestation on the roots, leading to mushy root growth and yellowing of bottom leaves.
- Start with quarantining your plant for treatment, and do not reintroduce it for at least another two weeks.
- Remove the infected leaves and stems by pruning them with a sterilized gardening shear.
- For root rot, slide the plant prune off dark, mushy roots and apply some fungicide before transplanting in a fresh potting mix.
- Next, wash the plant with a soapy water solution to remove the traces of pests and pest eggs.
- Alternatively, you can rub Neem oil or commercial horticultural oil over the plant to effectively treat them.
- For more than one infected plant, spray them with commercial houseplant fungicide
Some yellowing of Dieffenbachia leaves natural with age and seasonal change.
However, beware of excessive yellowing foliage and other troubling signs mentioned in this article.
An early diagnosis and treatment will help recover your plant before things get out of your hand.