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Why is the base of an orchid turning yellow and what to do about it?

Maria Popova, florist
Last reviewed: 19.01.2025

Orchids are stunning plants that attract attention with their beautiful flowers and graceful leaf shapes. However, sometimes there is a problem when the base of an orchid starts to turn yellow. In this article, we will examine the causes of yellowing in detail and suggest ways to solve this problem.

The base of an orchid is turning yellow: main causes

Yellowing at the base of an orchid, where the leaves connect to the pseudobulb or stem, can be caused by various factors, such as improper care, unfavorable environmental conditions, or diseases. To address this issue effectively, it's essential to identify the root cause and take appropriate action. Below are the main causes and solutions.

Natural leaf aging

Cause:

Orchid leaves naturally age, turn yellow, and die off over time. This typically affects the lower leaves.

Symptoms:

One or two older leaves turn yellow at the base, while the rest of the plant remains healthy.

What to do:

No action is necessary if the rest of the plant looks healthy.
Once the leaf completely dries out, gently remove it to prevent rot.

Overwatering

Cause:

Excessive watering or water stagnation in the substrate creates ideal conditions for root and base rot.

Symptoms:

The base becomes soft and mushy.
A foul odor may be present.
Roots turn dark and appear mushy or brittle.

What to do:

Remove the plant from its pot.
Thoroughly clean the roots of old substrate.
Trim away damaged roots and base tissue with a sterile tool, cutting slightly into healthy tissue.
Treat the cut areas with activated charcoal or a fungicide.
Repot the orchid in fresh, well-draining substrate.
Avoid watering for 5–7 days to allow cuts to heal.

Insufficient or excessive light

Cause:

Lack of light weakens the plant, potentially causing yellowing at the base.
Excessive light, especially direct sunlight, causes burns.

Symptoms:

With insufficient light: pale leaves and stunted growth.
With excessive light: dark brown or yellow spots with dry edges.

What to do:

Move the plant to a location with bright, indirect light.
If the window receives too much direct sun, use curtains or blinds for shading.

Low air humidity

Cause:

Low humidity, especially during the heating season, can lead to tissue dehydration and yellowing at the base.

Symptoms:

Yellowing is accompanied by dryness at the base edges and leaf wrinkling.

What to do:

Maintain air humidity at 50–70%.
Use a humidifier or place a tray with water and pebbles near the plant.
Avoid placing the orchid near heating devices.

Cold stress

Cause:

Exposure to low temperatures or drafts.

Symptoms:

The base and leaves turn yellow and lose firmness.
Wet or dry patches may appear on the leaves.

What to do:

Relocate the plant to a location with a temperature of 68–77°f (20–25°c).
Avoid drafts and placing the orchid near air conditioners or open windows.

Diseases and infections

Cause:

Fungal or bacterial infections often develop in conditions of overwatering or poor ventilation.

Symptoms:

Yellowing is accompanied by dark spots, soft areas, or a slimy coating.
The base may rot.

What to do:

Remove infected parts with a sterile tool.
Treat the plant with a fungicide or bactericide suitable for orchids.
Improve air circulation and reduce watering frequency.

Mechanical damage

Cause:

Injuries sustained during repotting or accidental handling.

Symptoms:

Only the damaged areas turn yellow, and the issue does not spread further.

What to do:

Cut away damaged parts with a sterile tool.
Treat the cuts with activated charcoal.
Handle the plant carefully during care and repotting.

Nutrient deficiency

Cause:

Lack of magnesium, nitrogen, or iron can cause yellowing at the base.

Symptoms:

Leaves first become pale and then yellow at the base.

What to do:

Use balanced orchid fertilizers containing micro- and macronutrients.
Fertilize every 2–3 weeks during the active growth period.

Preventing yellowing at the orchid base

Proper watering:
- Water only when the substrate is completely dry.
- Use soft, filtered, or settled water.
Optimal lighting:
Provide bright, indirect light.
Avoid direct sunlight exposure.
Maintain humidity levels of 50–70%.
Check the roots and base regularly to detect issues early.
Repot the orchid every 2–3 years into fresh, well-draining substrate.
Humidity control:
Regular inspections:
Appropriate substrate:

The base of orchid leaves is turning yellow: causes and solutions

Yellowing at the base of orchid leaves can be caused by natural processes, improper care, or diseases. Identifying the exact cause is essential for addressing the issue. Below are the main factors that lead to yellowing at the base of leaves and how to resolve them.

Natural aging of leaves

Cause:

Orchid leaves have a limited lifespan and naturally yellow and die off over time. This typically affects the lower leaves.

Symptoms:

Yellowing starts at the base and affects one or two lower leaves.
The rest of the plant remains healthy.

What to do:

This is a normal process, so no action is needed.
Remove dried leaves only after they completely detach from the plant to prevent rot.

Overwatering

Cause:

Excessive watering causes water to stagnate in the substrate, leading to root rot and yellowing of leaves.

Symptoms:

The base of the leaves becomes soft and yellow.
Roots appear dark, soft, and may emit a foul odor.

What to do:

Remove the orchid from its pot.
Gently clean the roots of the old substrate.
Trim away any damaged roots with sterile tools.
Treat the cuts with activated charcoal or cinnamon.
Repot the orchid in fresh, well-draining substrate and refrain from watering for 5–7 days.

Underwatering

Cause:

Insufficient watering causes the orchid to draw moisture from its leaves, leading to yellowing and dehydration.

Symptoms:

Leaves lose firmness, appear wrinkled, and turn yellow at the base.

What to do:

Water the orchid by immersing the pot in lukewarm, soft water for 15–20 minutes.
Maintain a proper watering schedule: water only when the substrate is completely dry.

Improper lighting

Cause:

Insufficient light slows photosynthesis, leading to yellowing leaves.
Excessive direct sunlight causes burns.

Symptoms:

With insufficient light, leaves become pale and yellow.
With excessive light, yellow spots develop and may turn brown over time.

What to do:

Place the orchid in a spot with bright, indirect light.
Use curtains or blinds to filter direct sunlight if necessary.

Low humidity

Cause:

Dry air, particularly during the heating season, can cause leaf dehydration and yellowing at the base.

Symptoms:

Leaf tips and edges may curl and dry out, accompanied by yellowing.

What to do:

Maintain humidity levels between 50–70%.
Use a humidifier, or place a tray with water and pebbles near the plant.
Mist the air around the orchid without wetting the leaves directly.

Nutrient deficiency

Cause:

A lack of nitrogen, magnesium, or iron in fertilizer can cause yellowing at the base of leaves.

Symptoms:

Yellowing starts at the base and spreads upward.

What to do:

Feed the orchid with a balanced fertilizer rich in nitrogen, phosphorus, and potassium.
Use fertilizer at half the recommended strength every 2–3 weeks during active growth.

Fungal or bacterial infections

Cause:

High humidity, overwatering, and poor air circulation promote infections.

Symptoms:

Yellow spots at the base of leaves become soft or slimy.
The leaves may rot and fall off.

What to do:

Remove the affected leaves with sterile tools.
Treat the plant with a fungicide or bactericide suitable for orchids.
Improve air circulation around the plant and reduce watering.

Cold damage

Cause:

Exposure to low temperatures or drafts stresses the plant.

Symptoms:

Leaves turn yellow at the base, soften, and wilt.

What to do:

Move the orchid to a location with temperatures between 20–25°c (68–77°f).
Avoid placing it near open windows or air conditioning units.

Prevention of yellowing at the base of orchid leaves

Proper watering:
- Water only after the substrate has completely dried out.
Adequate lighting:
- Provide bright, indirect light.
Humidity control:
- Maintain air humidity at 50–70%.
Regular fertilization:
- Use orchid-specific fertilizers with essential nutrients.
Disease prevention:
- Inspect the plant regularly and treat any issues promptly with fungicides or bactericides.

The base of an orchid has rotted: what to do?

If the base of an orchid has rotted, it is important to act quickly. This usually occurs due to improper watering or using a substrate that is too dense and poorly aerated. Rot at the base is a serious problem, as it can quickly spread to the entire plant.

Orchid is rotting at the base, what to do? The first step is to remove the plant from the pot, cut off all rotten parts of the roots and base. The cut areas should be treated with activated charcoal or a specialized fungicide to prevent further spread of the infection. After treatment, the orchid is repotted into fresh, loose substrate specifically designed for epiphytes, with added bark pieces and sphagnum moss.

The base of an orchid is turning black: causes and treatment

Sometimes, instead of yellowing, you may notice that the base of an orchid is turning black. This can be caused by overwatering or fungal diseases. Why are the roots turning black at the base of an orchid? Usually, the cause is the presence of pathogenic fungi that thrive in excessive moisture conditions.

If the bases of an orchid's roots are turning black, it is necessary to carefully inspect the root system and remove all affected parts. Use sterile tools to avoid introducing infection. After removing all damaged areas, the plant should be repotted and treated with a fungicide.

Leaves of orchid falling off at the base: causes and solutions

The falling off of orchid leaves at the base can be caused by natural aging, improper care, diseases, or stress from environmental factors. Identifying the cause is essential for addressing the issue and preventing further leaf loss.

Natural aging of leaves

Cause:

In orchids, lower leaves have a limited life span. Over time, they yellow, wilt, and fall off.

Symptoms:

Only the lower leaves are affected, while the rest of the plant appears healthy.
Leaves turn yellow gradually without spots or deformation.

What to do:

This is a normal process and does not require intervention.
Remove fully dried leaves by hand or with a sterile tool to avoid rot.

Overwatering

Cause:

Excessive watering or waterlogged substrate can lead to root rot, causing leaf loss.

Symptoms:

Leaves yellow, become soft at the base, and fall off.
Roots appear dark, mushy, and may emit a foul odor.

What to do:

Remove the plant from its pot and inspect the roots.
Cut away any rotten or damaged roots with a sterile tool.
Treat cut areas with activated charcoal or cinnamon.
Repot the orchid in fresh, well-draining substrate.
Reduce watering frequency; water only when the substrate is completely dry.

Underwatering

Cause:

Insufficient watering causes dehydration, prompting the plant to shed leaves to conserve moisture.

Symptoms:

Leaves become wrinkled, limp, and fall off.
Roots appear dry, white, or gray.

What to do:

Soak the orchid pot in lukewarm water for 15–20 minutes.
Water the plant regularly, ensuring the substrate does not completely dry out.
Maintain air humidity at 50–70%.

Low humidity

Cause:

Dry air, especially during the heating season, can stress the plant and lead to leaf loss.

Symptoms:

Leaves lose firmness, yellow at the base, and fall off.
Leaf tips may dry out.

What to do:

Increase air humidity using a humidifier or a tray with water and pebbles.
Regularly mist the air around the plant, avoiding direct water contact on the leaves.

Insufficient lighting

Cause:

Inadequate light slows down photosynthesis, weakening the plant and causing leaf loss.

Symptoms:

Leaves become pale, soft, and fall off.
Growth slows down.

What to do:

Move the orchid to a bright location with indirect light.
Use grow lights during the winter months if natural light is insufficient.

Over-fertilization

Cause:

Over-fertilizing leads to salt buildup in the substrate, damaging the roots and stressing the plant.

Symptoms:

Leaves yellow at the base and fall off.
A white residue may appear on the substrate and roots.

What to do:

Flush the substrate with lukewarm water to remove excess salts.
Reduce fertilizer concentration to half the recommended dose.
Fertilize only once every 2–3 weeks during active growth.

Root issues

Cause:

Damaged or rotted roots cannot absorb water and nutrients effectively, leading to leaf loss.

Symptoms:

Brown or black roots, sometimes mushy or brittle.
Leaves become soft and fall off.

What to do:

Inspect the roots by removing the plant from its pot.
Trim any damaged roots with a sterile tool.
Treat cuts with activated charcoal or cinnamon.
Repot the orchid in a fresh, well-aerated substrate.

Sudden temperature changes or drafts

Cause:

Exposure to cold drafts or sudden temperature fluctuations stresses the plant, causing leaves to fall off.

Symptoms:

Leaves become watery, yellow, and fall off.
Often occurs after transport or environmental changes.

What to do:

Place the orchid in a stable environment with temperatures between 68–77°f (20–25°c).
Avoid placing the orchid near open windows, air conditioners, or heating vents.

Diseases (fungal or bacterial infections)

Cause:

Overwatering or poor ventilation can lead to infections.

Symptoms:

Leaves yellow with soft, wet spots near the base.
May emit an unpleasant smell.

What to do:

Remove infected leaves with a sterile tool.
Treat the plant with a suitable fungicide or bactericide.
Improve air circulation around the plant.

Aging of the plant

Cause:

As orchids age, their leaf production slows, and older leaves fall off.

Symptoms:

Gradual reduction in new leaf production.
Older leaves yellow and drop naturally.

What to do:

Focus on overall care, including proper watering, fertilization, and lighting.
Remove dried leaves to encourage new growth.

Appearance of orchid keikis at the base

Not all changes at the base of an orchid are due to problems. Sometimes orchid keikis (baby plants) appear at the base — these are young shoots that can grow into full-fledged plants.

How to separate a keiki at the base of an orchid? When the keiki reaches a size of 5-7 cm and develops roots, it can be carefully separated from the mother plant and potted separately.

Summary and care recommendations

If the base of an orchid has turned yellow or the leaves of an orchid are turning black at the base, do not panic. It is important to carefully monitor the plant's condition and take timely measures to correct the situation. Key recommendations:

Control watering: avoid overwatering or drying out the substrate.
Maintain optimal conditions: light level, temperature, and humidity should be within the recommended range for orchids.
Treatment and prevention: at the first signs of rot, use fungicides and treat cuts with activated charcoal.
Regular feeding: use specialized orchid fertilizers to avoid nutrient deficiencies.

Thus, with proper care, many problems such as yellowing of orchid leaves from the base or rotting of the orchid base can be avoided. The main thing is to maintain a balance in care and pay close attention to changes in the plant's condition, so that you can respond to emerging difficulties in a timely manner.