Fungi belong to a group of organisms in their own right, being neither plant nor animal. They are very important to other living things. For example, some species help tree roots get nutrients from the soil, and others recycle dead and decaying matter like wood. Some types of fungi parasitise plants and animals. Some fungi, like the beautiful wood shank fungus that grows in holes in the trunks of living trees, can live with their host for many years. Other fungi, like the more dangerous types of honey fungus, can kill plants. For most of the year fungi are present as string-like mycelium, which usually lives underground. Mushrooms are usually the only part we see. Their fruiting bodies send spores into the air to settle in new places. Mushrooms come in a variety of beautiful shapes and sizes.
There are an amazing 15,000 species of fungi and wild mushrooms in the British Isles. They can be found in many places, but most of the time they are in woodlands, fields, and grasslands. You might even find some growing in your own garden!
Fungi are ubiquitous in gardens and play a vital role in the ecosystem. While some fungi are beneficial others can become problematic and infect plants. Accurately identifying the types of fungi in your garden is crucial for effective management. In this comprehensive guide, we will explore the most frequently encountered fungi in gardens and provide tips for prevention and treatment.
Powdery Mildew
Powdery mildew is one of the most common fungi found in gardens. It manifests as a white or gray powdery coating on the leaves, stems, and flowers of affected plants. The fungus thrives in humid, shaded environments. Powdery mildew often infects lilacs, roses, phlox, squash, cucumbers, and other plants. To treat powdery mildew, improve air circulation around plants and avoid overhead watering. Organic fungicides containing neem oil or sulfur can help control infections.
Downy Mildew
Downy mildew is another frequent fungal culprit in gardens. It appears as yellowish patches or spots on the upper sides of leaves, often with gray fuzz on the undersides. Downy mildew favors moist conditions and commonly impacts basil, roses, grapes, cucumbers, and cole crops. Prevent downy mildew by spacing plants properly for good air flow. Copper-based fungicides applied at the first sign of infection can treat existing infections.
Rust
Rust fungus is easy to identify by the reddish-orange spots it creates on leaves, stems, and flowers. Roses, snapdragons, geraniums, and hollyhocks are prone to rust. The fungus thrives in wet, humid weather. Improving air circulation and pruning infected parts of the plant can help manage rust. Fungicides containing sulfur or neem oil work well for treatment.
Leaf Spot
Leaf spot fungi manifest as small, circular spots or lesions on plant foliage. The spots vary in color from black to brown, gray, or tan depending on the causal fungus. Leaf spot impacts a wide range of plants, including roses, cucumbers, tomatoes, squash, and hydrangeas. Avoid overhead irrigation and promptly remove diseased leaves to prevent spread. Fungicides applied early can treat existing infections effectively.
Damping-Off
Damping-off is a common soil-borne fungal disease that infects seeds and seedlings, causing them to rot and collapse. It thrives in wet poorly drained soils. To prevent damping-off use sterile soilless seed starting mix and avoid overwatering. Let the soil dry between waterings. Fungicide drenches can help reduce damping-off infections.
Slime Molds
Slime molds appear as colorful, gelatinous masses on plant surfaces, mulch, or soil. They feed on decaying organic matter and are not parasitic to live plants. Slime molds may look alarming but are harmless. Simply hosing them off plants or improving drainage often provides adequate control.
Mushrooms
Mushrooms and toadstools popping up in gardens are fungi. Most are beneficial, helping decompose organic matter. Avoid eating wild mushrooms unless positively identified. Puffballs, morels, chanterelles and oyster mushrooms are edible species sometimes found in gardens. Poisonous mushrooms like the death cap should be removed carefully to avoid touching them.
Wood and Root Rotting Fungi
Fungi like armillaria, honey fungus and phytophthora infect woody plant roots and stems, causing cankers, dieback and root rot. They spread through soil and survive on dead wood. Avoid wounding tree trunks and keep mulch from touching stems. Remove dead trees and roots as these provide food for the fungi. Fungicides applied as soil drenches can suppress infections.
Fruit and Vegetable Fungi
Several fungi infect fruits and vegetables, manifesting as fuzzy mold, spots, or rots. Grey mold, black spot, anthracnose, early blight, and botrytis are some examples. These fungi thrive in wet conditions. To prevent infections, promote airflow, use drip irrigation, apply mulch, and avoid crowding plants. Remove weeds and infected material promptly. Fungicides applied preventively can protect crops.
Ornamental Plant Fungi
A wide range of fungi affect ornamental plants, especially in wet weather. Black spot on roses, iris leaf spot, hollyhock rust, hydrangea leaf spot, and verticillium wilt on shrubs are some common examples. Improve drainage, avoid overhead watering, and prune out infected parts to manage these diseases. Applying appropriate fungicides at the first sign of infection is recommended.
Properly identifying fungi is the first step toward effective treatment. Always examine plants thoroughly and look for diagnostic symptoms. Promptly address infections by improving cultural practices and applying organic or chemical fungicides. With vigilance and integrated pest management techniques, gardeners can minimize the impact of harmful fungi on their plants.
Shaggy ink cap (Coprinus comatus)
Cap: 5-15cm wide, pale, woolly scales, bell-like then conical.
Stem: tall (up to 20cm) and narrow.
Gills: white, then pink, then dissolving to drip black ‘ink’.
Edibility: edible, tasty when young (before ink), but if consumed with alcohol produces mild poison.
Sulphur tuft (Hypholoma fasciculare)
Cap: 4-8cm across, convex, or domed, bright sulphur yellow with orange tints and a brown centre.
Gills: yellow, then green and brown.
Stem: long and fibrous. Sprouts in large tufts, with often hundreds of caps, from tree stumps and logs.
Edibility: inedible.
12 Mushrooms That Grow In Your Yard
FAQ
What are the best fungi for garden soil?
Is fungus in the garden good or bad?
How do you identify fungus on plants?
What are the 10 soil fungi?
What are the different types of Garden fungi?
Fungi can manifest in various forms, including spots, patches, discolorations, powdery coatings, or mold-like growth on plants and soil. Some common types of garden fungi include powdery mildew, downy mildew, rust, leaf spot, and damping-off disease.
Are fungi bad for the garden?
Common types of fungi include fairy ring fungus (Marasmius oreades), which grows in lawns and causes no damage, and jelly ear fungus (Auricularia auricula-judae), which grows on dead wood, particularly elder. However, as mentioned above, some fungi can be bad for the garden. These include honey fungus, which can kill plants, shrubs and trees.
Where can fungi be found in a garden?
In the garden, the tiny fungi (under 1/4 inch tall) are usually found on the surface of soil that has been enriched with manure, sawdust or wood chips. They can also be found on old boards used to edge garden beds and on wooden plant labels and stakes. The fungi are usually spread in manure, but some species may contaminate seed mixes.
What are the most common garden fungus issues?
With that in mind, here are eight of the most common garden fungus issues. Powdery mildew is one of the easiest to figure out in terms of garden fungus identification, mostly because it looks exactly how you’d expect: like someone has coated the leaves of your plant with a fine dusting of powder.
Do fungi kill plants?
Since these fungi live only on decaying plant matter, they do not harm living plants. In the garden, the tiny fungi (under 1/4 inch tall) are usually found on the surface of soil that has been enriched with manure, sawdust or wood chips. They can also be found on old boards used to edge garden beds and on wooden plant labels and stakes.
Why is identifying garden fungi important?
Identifying garden fungi is a critical step in maintaining plant health and ensuring the vitality of your garden. I am well aware that fungi can lead to fungal diseases which can be detrimental to both ornamental and edible plants. Quick identification and proper treatment can prevent the spread of disease and the potential loss of plant life.