Those toadstools, puffballs, earth-stars and other fungi springing up now can alarm gardeners. Digging out fungi or applying fungicides is futile and counterproductive, as fungi are vital for soil fertility and plant health, and support creatures including beetles, woodlice and worms, which in turn feed frogs, birds and other garden wildlife.
Potential harm to children and pets is not borne out by experience. However, where pets or young children might eat them, sweeping up and disposing of fungi in the compost bin or green waste is a sensible precaution.
Only a very few are significant garden problems that have to be managed – the honey-coloured toadstools of honey fungus, lawn fairy rings and bracket fungi on trees, for example. The rest are welcome in gardens, unlike mildews and other plant diseases. These are called microfungi and release spores without a fruiting body.
New FeatureIn ShortQuick Stories. Same trusted journalism.
Toadstools and other “fruiting bodies” are a small proportion of the total mass of a fungus, the rest being present all year underground, as strands of mycelium, or within wood, for example, living on dead organic matter and sometimes on secretions of plant roots. Once the unseen fungal mass matures, it produces fruiting bodies.
Mycorrhizal fungi live closely with roots in a mutually beneficial relationship, whereby the plant gives the fungus sugars and the fungus acquires water and nutrients, and protects against root pathogens. Truffles, an underground fruiting body, are mycorrhizal. Almost all plants except brassicas are potentially mycorrhizal.
Soil-dwelling fungi are also ubiquitous, permeating the ground with their strands and binding soil minerals into lumps that improve soil texture and plant growth.
Fungi multiply and spread by spores rather than seeds. Toadstools and other fruiting bodies release masses of tiny airborne spores, which spread widely and are triggered into growth by warm, wet spring weather or rain after a dry period.
Fairy rings on lawns are caused by various fungi, only one of which kills grass (Marasmius oreades). It first stimulates the grass, resulting in a bright green circle, but then kills the grass, followed at times by a ring of toadstools. Other fairy ring fungi don’t harm the grass and even seem to stimulate it. The toadstools can be collected or picked up by the lawnmower if they displease.
Fungi loves wood and bark (Photo: Tim Sandall)
Wood and bark chip mulch support numerous fungi that colonise the woody substrate, digesting the unpromising wood by clever chemistry, turning it into plant food and soil improver. Research by the RHS has shown that honey fungus is not promoted by commercial mulches. To be sure, burn any honey fungus-affected material in your garden rather than shred it for use as mulch.
Tiny toadstools can also be a “feature” of peat-free potting composts, supported by the wood fibre component, but again they are not associated with any harm to plants or gardeners.
Fungal growths on trunks and branches of trees and shrubs are usually associated with dead wood. Coral spot is a common example that can infect living wood, usually because the tree is sickly, but mostly affecting dead shoots and pruning stubs. Bracket fungi are formed by fungal growth in the heart of trees rotting the timber. Eventually the tree is so weakened that it topples. This can take some years and, where bracket fungi are seen, a qualified arborist can advise on the risks and fell if required.
Boosting fungi populations by sustainable gardening techniques including mulching, limiting digging, making log and stick piles of prunings, leaving fallen leaves to rot and tolerating toadstools is a powerful, and fascinating, way to enhance garden wildlife.
Comments are closed.