How often should you mow the lawn? This question has been the subject of heated debate for years. Whilst advocates of short grass favour aesthetics and ease of use, naturalists consistently emphasise the importance of taller plants for insects and other organisms. An interdisciplinary team from the Jagiellonian University spent three years searching for the right balance. The research was conducted on the grounds of the Jagiellonian University’s 600th Anniversary of the University’s Restoration Campus in Kraków. What did they find?
72 plots and thousands of observations
In 2023, 72 research plots were established on the Jagiellonian University’s Third Campus, where different mowing frequencies were applied. Some areas were mowed once a year, others several or a dozen times, and some were left untouched for up to two years. As the season progressed, the differences between the individual plots became increasingly apparent. The researchers analysed the composition of the vegetation, the abundance of insects and other invertebrates, the activity of soil organisms, as well as temperature and humidity conditions. The research also covered bacteria, fungi and soil quality, including the presence of heavy metals and petroleum-derived substances. This made it possible to observe the effects of different methods of maintaining green spaces under real-world conditions.
How often should you mow the lawn?
The research findings indicate that mowing too frequently reduces biodiversity. On lawns mowed six to 12 times a year, there was a marked decline in flowering plants, and with them, shelter and food sources for many insect species. There were fewer bees, butterflies and grasshoppers, amongst others. Effects were also observed beneath the soil surface. Regular cutting of vegetation weakened the activity of soil organisms, including earthworms responsible for maintaining soil fertility. In addition, the exposed soil heated up more quickly and retained moisture less effectively, which affected the functioning of the entire small ecosystem of the plot.
Ticks after mowing
One of the most frequently cited arguments in favour of frequent mowing is the fear of ticks. However, the results of the experiment proved to be more complex. Ticks were found in plots with very different vegetation heights, ranging from areas mowed monthly to sites left almost entirely untouched by humans. The researchers emphasise that the number of observations was limited, so the subject requires further analysis. The results so far suggest, however, that regularly cutting the grass does not guarantee a reduction in the presence of ticks. A short lawn therefore does not act as an effective protective barrier.
How often should you mow the lawn? Preferably less often
Experts point out that completely abandoning mowing is also not beneficial for the soil. Under such conditions, individual plant species, including invasive ones, may gain the upper hand, leading to a decline in biodiversity. A moderate approach yields the best results. Scientists recommend mowing less frequently, ideally no more than once a month, and leaving parts of the area untouched by human intervention. This mosaic of patches with varying plant heights creates suitable conditions for many groups of organisms. The findings of the research were used to create the online application “To mow or not to mow?”, which helps users make decisions regarding the maintenance of green spaces and explains the interrelationships within urban ecosystems.
Source: uj.edu.pl
Read also: Flower meadows| Ecology|Greenery|City|whiteMAD on Instagram
