In addition to being unsightly on an otherwise blemish-free lawn, worm casts provide ideal sites for weed development, encourage turf diseases, and disrupt playing surfaces. They are also known to attract moles. Worm casts are easily smeared when the lawn is walked on or mowed, resulting in slippery ‘pancakes’ of earth, under which the grass will deteriorate.
Worm casts are produced mainly in the autumn, typically from September to October, and in the spring, from March to early May, when the soil is moist and reasonably warm. They may also be found in winter if the weather is sufficiently mild. At these times the worms are closer to the surface; when the soil is cold and / or dry the worms go deeper into the soil, with a reduction in worm casts the result.
Although worm casts can be removed by sweeping the lawn, this is only practical if the casts are dry and the area in question is not too large.
Pesticides for the control of worm casts are no longer available to home gardeners. However, Four Seasons Lawn Care can apply a professional product that will control the worm casts, by deterring worms from being active in the top inch or so of the lawn. The treatment does not harm the worms, and they are able to continue their good work in the garden, e.g., by aerating the soil. We hold the necessary Certificate of Competence to use professional products.
The treatment is usually applied in early spring and autumn. Please ask if you would like further details.