Earthworms and your lawn
Earthworms and your lawn
Benefits - and challenges - of earthworms for your lawn
Earthworms – fascinating creatures belonging to the phylum Annelida – are not just a part of your lawn’s ecosystem, they are the backbone of it. With their long, segmented bodies, these invertebrates are the unsung heroes that keep your soil and lawn healthy
Earthworms are beneficial for lawns in many ways. Their burrowing activities create channels in the soil that help to aerate it, allowing air and water to reach the roots of plants. This, in turn, promotes healthy root growth and nutrient uptake, leading to healthier and more robust plants. Earthworms also break down organic matter in the soil, which helps release nutrients essential for plant growth.
Earthworms on sports surfaces
Like any other creature, earthworms have downsides in managed sports fields, golf courses, and fine-cut home lawns. Some examples are:
Casting: Earthworms leave small mounds of expelled soil on the surface, known as castings or worm casts. These castings can interfere with the smooth surface needed for activities like golfing or playing field sports. These mounds can cause wear on expensive specialised mowing equipment during the colder months in particular. It’s often the number one reason people raise their HOC (height of cut) during the colder months and switch to traditional rotary mowing.
Soil disturbance: The constant movement of earthworms can disturb the soil structure, affecting drainage and aeration in ways that are detrimental to the health of the turf. This is particularly the case in sand profiles where earthworms burrow up from the soil beneath and create tunnels that contaminate the sand profile with soil.
Surface unevenness: The burrowing activity of earthworms can cause unevenness and bumps in the turf surface, making it uneven for activities that require a flat, smooth playing surface.
How does the professional turf industry manage worms?
If you are experiencing problems with earthworms, there are several things you can do to mitigate the damage. In New Zealand, several products used in the professional turf industry are sold as organic fertilisers. These are not marketed as worm control, but it’s well known that they control worms. These products are normally based on Tea Saponin and come in liquid or granular form.
Home lawns
It’s important to note that while earthworms can be a problem under certain circumstances, they are generally beneficial and should be encouraged whenever possible in home lawns. Increasing your mowing height in late autumn could be the simple solution over winter.
