Toadstools in newly turfed lawns

"What are they?" Toadstools are the fruiting bodies of the class of fungi known as basidiomycetes. There are over 13,000 species of this class of fungus. The vegetative part of the fungus lives below ground, feeding on dead plant material and speeding the process of its decay. This breaking down of dead material occurs throughout nature and allows the release of nutrients to feed living organisms. When the ideal environmental conditions occur the fungus reproduces by producing spores in the toadstools. These are of course above the surface of the ground and allow wind dispersal of the spores.
"I didn't have toadstools in my old lawn so where did they come from?"
When the soil is being prepared ready for the new turf to be laid buried organic debris is disturbed and bought up to the surface. The spores are triggered when the conditions are ideal i.e. mild and wet causing a flush of toadstools. Eventually, when the supply of nutrient in the turf is used up and the fungus dies out, no more toadstools are produced. Invariably they do not recur in the year following laying.
"Do they damage the turf?"
No. The fungus is not a "disease" and is quite distinct from those fungi, which cause "fairy rings" in the turf. In fact by breaking down dead material they are benficial.
"Are they poisonous to children and pets?"
The small brown toadstools which occur most frequently in new turf are not poisonous. However, we would not recommend eating any wild toadstool or mushroom unless a positive identification has been made by a qualified person.
"Can they be controlled?"
Since they are composed mainly of water toadstools soon shrivel up and disappear when brushed with a stiff brush/besam broom or removed with the lawn mowings.
In our experience the flush of small brown toadstools which occur in summer following laying of the turf is not repeated in succeeding years, although occasional toadstools will be produced from time to time - as in any lawn.