Published On:
November 15, 2023

Understanding Mould on Plants: Causes and Solutions

Many individuals, particularly millennials, have turned to indoor plants as a hobby and stress reliever, especially during times of isolation at the peak of the COVID-19 pandemic. This surge in interest is attributed to the therapeutic and aesthetic benefits of nurturing indoor plants, as well as the need for connection to nature during periods of isolation.

It's thus important for these plant enthusiasts to keep their plants healthy and away from diseases like root rot and fungal diseases for optimum plant growth.

In this article, we aim to delve into the world of fungal growth as a plant disease, the reasons behind mould growth, the most susceptible plants, common types of fungi, differentiation between mould and powdery mildew, treatment and prevention strategies, and when to seek professional help.

Fungal Growth as Plant Diseases

Fungal growth on plants is a widespread problem that can lead to devastating consequences if left unattended. The presence of mould and powdery mildew on plants is often indicative of an underlying issue that needs to be addressed promptly.

These fungal diseases can stunt the growth of plants, weaken their immune systems, and even lead to their untimely demise. Therefore, every gardener must understand the nature of these diseases and how to effectively combat them.

Why Do Moulds Grow On Plants?

Moulds thrive in environments that offer the perfect combination of moisture, warmth, and organic matter. When these conditions are met, mold spores can germinate and colonise the surfaces of plants, leading to the formation of unsightly mould colonies. It's essential to recognise that the presence of mould on plants is often a symptom of an underlying issue rather than the primary problem itself.

Excessive moisture, poor air circulation, and overcrowding of plants can create an ideal breeding ground for mould. Furthermore, stressors such as nutrient deficiencies, physical damage, and environmental fluctuations can weaken the plants' natural defences, making them more susceptible to mould infestations.

Most Susceptible Plants to Mould Growth

While mould can potentially affect a wide range of plant species, certain plants are inherently more susceptible to mould infestations. These plants may possess characteristics that make them more vulnerable to the environmental conditions conducive to mold growth, or they may be predisposed to specific fungal diseases.

Regardless, identifying the plants that are most at risk of mould growth allows us to proactively implement targeted preventive measures and provide them with the care they need to thrive.

Tender ornamental plants, such as roses, zinnias, and begonias, are often prone to powdery mildew due to their lush foliage and susceptibility to stress. Additionally, fruit-bearing plants like squash, lettuce, cucumbers, and melons are highly susceptible to mould infestations, especially when grown in humid climates or crowded conditions.

Common Fungus Types that Grow On Plants

Fungi are a diverse group of organisms that can manifest in various forms on plants, each presenting its own set of challenges and treatment requirements. Understanding the characteristics and behaviours of common fungus types is essential for effective identification and management of plant diseases.

White Mould

White mold, also known as Sclerotinia, is a fungal disease that can affect a wide range of plants, including vegetables, ornamentals, and even trees. This type of mould typically appears as fluffy white growth on the affected plant parts, often accompanied by a soft, watery rot. White mould thrives in cool, humid conditions and can spread rapidly, posing a significant threat to the affected plants.

Black Mould

Black mold, or sooty mold, is a common fungal disease that manifests as a dark, velvety growth on the surfaces of plants. This type of mould often develops in conjunction with honeydew-producing insects such as aphids, scales, or whiteflies. While black mould does not directly invade plant tissues, it can obstruct photosynthesis and weaken the overall health of the plants.

Powdery Mildew

Powdery mildew is a widespread fungal disease that affects a broad spectrum of plants, including ornamentals, vegetables, and fruit trees. This type of mould presents as a powdery white or grey growth on the leaves stems, and flowers of infected plants. Powdery mildew thrives in warm, dry conditions and can spread rapidly, especially in crowded or poorly ventilated environments.

Differentiating Moulds and Powdery Mildew

Distinguishing between moulds and powdery mildew is essential for accurate identification and targeted management of these fungal diseases. While both moulds and powdery mildew are fungal, they exhibit distinct characteristics that set them apart.

Moulds typically appear as fuzzy or woolly growth on the surfaces of plants, ranging in colour from white to grey, brown, or black, depending on the specific type of mould. These colonies can spread rapidly and may produce spores that contribute to the further propagation of the disease.

Powdery mildew, on the other hand, presents as a powdery white or grey coating on the leaves stems, and flowers of infected plants. Unlike moulds, powdery mildew does not typically form fuzzy growth or produce conspicuous spores. Instead, it creates a powdery residue that can be easily dislodged from the plant surfaces.

Can Moulds and Powdery Mildew Spread to Other Plants?

Moulds can spread to other plants through various means, including airborne spores, physical contact, and the transfer of contaminated tools or hands. Additionally, environmental conditions conducive to mould growth, such as high humidity and poor air circulation, can facilitate the spread of the disease among nearby plants.

Similarly, powdery mildew can easily spread to neighbouring plants through airborne spores and physical contact. As the disease progresses, it can produce a vast number of spores that are carried by the wind, potentially infecting surrounding plants and perpetuating the cycle of infestation.

How to Treat and Control Powdery Mildew and Mould On Plants

Effectively treating and controlling powdery mildew and mould on plants requires a multifaceted approach that addresses the underlying causes of the diseases and targets the specific characteristics of each fungal infestation.

Cultural Practices

Implementing cultural practices that promote plant health and reduce the likelihood of fungal diseases is a fundamental aspect of disease management. Proper site selection, adequate spacing between plants, and appropriate watering practices can create an environment that is less conducive to mould and powdery mildew growth. Additionally, removing and disposing of infected plant parts can help prevent the spread of diseases within the garden.

Fungal Treatments

Fungal treatments can be effective in managing powdery mildew and mould infestations. These treatments work by disrupting the fungal growth and preventing the spread of the diseases. Here are some common household remedies that can be used to treat powdery mildew and mould on plants:

Environmental Modifications

Modifying the growing environment to reduce favourable conditions for fungal growth is an integral part of disease control. Improving air circulation, reducing humidity, and providing adequate sunlight can help create an inhospitable environment for mould and powdery mildew. Additionally, avoiding overhead watering and watering plants at the base can minimise moisture accumulation on the foliage, reducing the risk of fungal diseases.

When to Ask for Professional Mould Removal Services

In some cases, the severity of mould infestations on plants may necessitate the intervention of professional mould removal services. While proactive management and preventive measures can effectively control many instances of mould and powdery mildew, certain situations may warrant the expertise of professionals to mitigate the impact of the diseases.

Severe mould infestations that have extensively compromised the health and appearance of the plants may require the expertise of professionals to assess the extent of the damage and implement targeted remediation strategies.

Singapore mould removal services, such as that offered by Nimbus Homes, can offer specialised treatments, such as chemical applications, physical removal of dead or diseased foliage, and environmental modifications, to effectively address severe infestations in your home. We also offer Singapore professional cleaning services that can complement these mould remediation efforts and keep your homes spotlessly clean.

How to Prevent Powdery Mildew and Mould Growth On Plants

Preventing powdery mildew and mould growth on plants is a proactive and essential aspect of plant care that can significantly reduce the occurrence and impact of fungal diseases. By implementing targeted preventative measures and maintaining a vigilant approach to plant health, we can create an environment that minimises the risk of mould infestations and promotes the flourishing of our garden.

Make Sure that Indoor and Outdoor Plants Get Enough Sunlight

Ensuring that indoor and outdoor plants get enough sunlight can help prevent powdery mildew and mould growth on plants. UV light, particularly UVC light, is effective at breaking down the DNA of mildew and mould in the early stages of growth.

Maintain Good Air Circulation

Maintaining proper air circulation around plants is crucial for preventing powdery mildew and mould growth. Adequate air circulation deters powdery mildew by reducing relative humidity and creating a more uniform climate, which inhibits the conditions in which powdery mildew thrives.

It's important to space plants appropriately and keep them away from walls and fences to ensure good air circulation, as this helps reduce the risk of powdery mildew and mould development by creating an environment that is less favourable for their growth.

Water Plants Appropriately

Proper watering techniques such as using soaker hoses and watering deeply can help prevent the development and spread of powdery mildew, which thrives in hot, wet conditions. Watering plants appropriately can prevent powdery mildew and mould growth by avoiding overhead watering, which can wet the foliage and potentially splash soil-borne fungi onto leaves.

Opt for Resistant Plant Varieties

Choosing plant varieties that exhibit resistance to powdery mildew and mould can significantly reduce the likelihood of disease development. Many plant species offer resistant cultivars that have been specifically bred to withstand fungal diseases, providing an added layer of protection for our garden.

Monitor and Maintain Plant Health

Regular monitoring of plant health and addressing any signs of stress or disease promptly can prevent the escalation of powdery mildew and mould infestations. By maintaining optimal growing conditions, providing adequate nutrition, and addressing any environmental stressors, we can bolster the natural defences of our plants and reduce their susceptibility to fungal diseases.

Implement Preventive Treatments

Proactively applying preventive treatments, such as horticultural oils, a natural fungicide, and cultural modifications, can create an environment that discourages fungal diseases. These treatments can be especially beneficial in high-risk environments or during periods of environmental stress, providing an additional layer of protection for our plants.

Final Words

Understanding the complexities of mould growth on plants and the nuances of powdery mildew is an invaluable asset for every gardener. By delving into the causes, susceptibility factors, treatment strategies, and preventative measures, we can equip ourselves with the knowledge to combat fungal diseases and protect our plant's health and beauty. With a proactive and informed approach, we can create an environment that minimises the risk of mould infestations and fosters the thriving of our garden.