Myth: Lawns are poor for wildlife and must be replaced with flowering meadows
 
Lawns are the largest habitat type in most private gardens and all parks.  In London, back garden lawns cover 33% by overall area, and 41% of the vegetated area1. In Sheffield, they were estimated to cover 60% of the total garden area2, so it is clearly worth making sure they pay their way for wildlife. However, lawns are also important for human exercise and enjoyment, especially in a household with growing children, so some compromise is needed. Conventional lawns have been described as “biological deserts”3 , but is this fair?
 
Lawn biodiversity
Because most people mow the lawn regularly, they are not aware of the remarkable plant diversity it may support.  The BUGS project made a detailed study of 52 garden lawns in Sheffield4 and found a total of 159 plant species, which averaged over a third of the total number of plant species in each garden. 20 grass and 14 moss species were present, the rest were “forbs”, non-grass herbaceous plants. Quadrats showed that the grasses covered 84% of the area.
 
Nearly 34% of the species were only found once, and the larger the area surveyed, the more species were discovered.  Many of the less commonly found species would not normally be able to grow to set seed in lawns, so their presence showed continual colonisation by imported seed or runners. Lawns had a modest number of very common species, well adapted by creeping or rosette growth, and lots of less common ones, showing similar trends to semi-natural grasslands.
 
.
 
 
Relaxing mowing and introducing plug plants can help shift a typical lawn into something closer to a meadow, but you will need to keep working at it.  Another and easier approach is to create a cornfield flower patch which looks a bit like a meadow and is flower-rich and is very attractive to pollinators and people alike. They are sown as a grass-free mix into bare garden soil but will need to be weeded and re-sown at the end of every year.
 
We will be creating pages on this site about lawn, meadow and cornfield patch management, but for now your best source of summary information is Adrian Thomas’s excellent book “Gardening for wildlife”8. Another highly recommended book is James Hewetson-Brown’s “How to make a wildflower meadow”9 which also introduces the new technique of laying wildflower turf.
 
 
References
 
1.  Smith, C., Dawson, D., Archer, J., Davies, M., Frith, M., Hughes, E. and Massini, P., 2011. From green to grey; observed changes in garden vegetation structure in London, 1998-2008, London Wildlife Trust, Greenspace Information for Greater London, and Greater London Authority.
 
2.  Gaston, K.J., Warren, P.H., Thompson, K. & Smith, R.M. 2005. Urban domestic gardens (IV): the extent of the resource and its associated features. Biodiversity and Conservation 14, 3327-3349.  Available here
 
3.  https://www.theguardian.com/lifeandstyle/shortcuts/2019/apr/24/why-you-should-turn-lawn-into-wildflower-meadow
  
4.  Thompson K., Hodgson J.G., Smith R.M., Warren P.H. and Gaston K.J. 2004. Urban domestic gardens (III): composition and diversity of lawn floras. J. Veg. Sci. 15: 371–376.   Available here
 
5.  Gibson, C.W.D.,  Hambler, C. and Brown, V. K. (1992).  Changes in Spider (Araneae) Assemblages in Relation to Succession and Grazing Management. J. Appl. Ecol. 29:132-142  Abstract here
 
6. Watson CJ, Carignan-Guillemette L, Turcotte C, Maire V, Proulx R. (2020) Ecological and economic benefits of low-intensity urban lawn management. J Appl Ecol. 57:436–446. Abstract here
  
7.  Lerman, S.B., Contosta A.R, Milam, J. and Bang, C.  (2018)   To mow or to mow less: Lawn mowing frequency affects bee abundance and diversity in suburban yards. Biological Conservation 221: 160-174 Abstract here 
  
8.  Thomas, A. (2017) Gardening for Wildlife. Bloomsbury Natural History pp 146-155
 
9.  Hewetson-Brown J. (2016) How to make a wildflower meadow Filbert Press Ltd.
 
 
 
Page written by Steve Head: Reviewed by Ken Thompson
The message for gardeners is that typical lawns are much richer in plant species than they realise. If they were to relax mowing, lawns would rapidly change in character as the supressed scarcer species were able to grow up.   For animals in lawns, the picture isn’t so clear.  BUGS didn’t sample lawns in isolation, but over the whole picture of diversity only sawflies showed a strong positive relation to lawn area, but the numbers of solitary wasps and harvestmen also correlated with lawn area.  We know lawns support root-feeding beetles and moths, ants and spiders, but some serious ecological sampling would be very useful, especially linked to patterns of mowing.
 
Improving lawns for wildlife
 
It is generally accepted that letting all or part of a lawn grow longer will allow more creatures to make a living, although perhaps limiting its use for human exercise. Butterflies like the meadow and hedge brown need longer growing grass as caterpillars and are easily attracted to gardens by leaving some lawn patches unmown. On the other hand, some solitary bees will nest in short grass but not in long grass, while the opposite may be true for bumblebees. In agricultural contexts, more spider species live in more structurally diverse (i.e. longer) grassland5. We need more studies on the optimum length to cut garden lawns to enhance animal biodiversity.  A global review of only 14 relevant published works confirmed that plants and animal diversity is reduced in intensively managed lawns, while “pests” – dandelions, ragwort and beetle larvae increased6.   One study in the USA showed that intermediate levels of mowing intensity were best for bees, allowing flowering without compromising access to the flowers7.
 
 
Part of Steve Head's lawn.  It has been left un-mown in key areas for a couple of years, and a number of flower species have appeared, helped with some plug planting.  You can see cowslip heads and yellow rattle in the foreground. 
 
Keeping the rest of the lawn mown helps make the long grass look intended rather than just untidy.
If you relax mowing, you will find some flowers soon appear, such as dandelions, clover and daisies, and others that also support pollinators.  Keeping a mown area around the edges and creating tidy paths through the long grass keeps it looking neat.  It is well worth trying some wildflower plug-plants in places where the grass won’t grow too long.  Cowslip is pretty tough and will spread.  You can also sow yellow rattle onto the cut grass in late autumn.  This annual is semi-parasitic and reduces the competitive growth of grass.
 
Wildflower meadows
 
These have become exceedingly fashionable among television and magazine pundits. There are few things more beautiful than a rough country meadow full of wild flowers in season, and unfortunately, they have become extremely rare.  However, there is real confusion in many people’s minds as to what a “meadow” is.
 
A true meadow is a permanent community of many species of grasses and perennial flowers but needs human intervention to survive without changing through time. Meadows are established by cutting and/or grazing, over many years. Having one would be a dream for most wildlife gardeners, but in the short term, establishing one is very challenging, mainly because typical garden soils are so fertile that grasses will outgrow and smother the flowers you are trying to encourage. If you can’t produce a low fertility area (for example by removing 10cm or more of fertile soil to expose subsoil, you really should not bother starting one from scratch.
 
This shows a neighbour's close-mown lawn.  It doesn't have very many flowers in it except suppressed buttercups, but those earth patches are mounds of excavated soil made by solitary ground-nesting bees of the genus Anthrenes.  In the early summer the lawn is alive with busy adult bees. 
 
If the owners allowed the lawn to grow long, the bees would have to nest elsewhere, so having some variety of lawn management is a really good thing.
A flower-rich true meadow on artificially raised ground near the river Thames. The soil is gravelly and drains readily, and is infertile.  The meadow is managed by cutting, and has many plant species including orchids, and marbled white and small blue butterflies.
Myth: Lawns are poor for wildlife and must be replaced with flowering meadows
 
Lawns are the largest habitat type in most private gardens and all parks.  In London, back garden lawns cover 33% by overall area, and 41% of the vegetated area1. In Sheffield, they were estimated to cover 60% of the total garden area2, so it is clearly worth making sure they pay their way for wildlife. However, lawns are also important for human exercise and enjoyment, especially in a household with growing children, so some compromise is needed. Conventional lawns have been described as “biological deserts”3 , but is this fair?
 
Lawn biodiversity
Because most people mow the lawn regularly, they are not aware of the remarkable plant diversity it may support.  The BUGS project made a detailed study of 52 garden lawns in Sheffield4 and found a total of 159 plant species, which averaged over a third of the total number of plant species in each garden. 20 grass and 14 moss species were present, the rest were “forbs”, non-grass herbaceous plants. Quadrats showed that the grasses covered 84% of the area.
 
Nearly 34% of the species were only found once, and the larger the area surveyed, the more species were discovered.  Many of the less commonly found species would not normally be able to grow to set seed in lawns, so their presence showed continual colonisation by imported seed or runners. Lawns had a modest number of very common species, well adapted by creeping or rosette growth, and lots of less common ones, showing similar trends to semi-natural grasslands.
 
 
Part of Steve Head's lawn.  It has been left un-mown in key areas for a couple of years, and a number of flower species have appeared, helped with some plug planting.  You can see cowslip heads and yellow rattle in the foreground. 
 
Keeping the rest of the lawn mown helps make the long grass look intended rather than just untidy.
 
The message for gardeners is that typical lawns are much richer in plant species than they realise. If they were to relax mowing, lawns would rapidly change in character as the supressed scarcer species were able to grow up.   For animals in lawns, the picture isn’t so clear.  BUGS didn’t sample lawns in isolation, but over the whole picture of diversity only sawflies showed a strong positive relation to lawn area, but the numbers of solitary wasps and harvestmen also correlated with lawn area.  We know lawns support root-feeding beetles and moths, ants and spiders, but some serious ecological sampling would be very useful, especially linked to patterns of mowing.
 
Improving lawns for wildlife
 
It is generally accepted that letting all or part of a lawn grow longer will allow more creatures to make a living, although perhaps limiting its use for human exercise. Butterflies like the meadow and hedge brown need longer growing grass as caterpillars and are easily attracted to gardens by leaving some lawn patches unmown. On the other hand, some solitary bees will nest in short grass but not in long grass, while the opposite may be true for bumblebees. In agricultural contexts, more spider species live in more structurally diverse (i.e. longer) grassland5. We need more studies on the optimum length to cut garden lawns to enhance animal biodiversity.  A global review of only 14 relevant published works confirmed that plants and animal diversity is reduced in intensively managed lawns, while “pests” – dandelions, ragwort and beetle larvae increased6.   One study in the USA showed that intermediate levels of mowing intensity were best for bees, allowing flowering without compromising access to the flowers7.
 
 
This shows a neighbour's close-mown lawn.  It doesn't have very many flowers in it except suppressed buttercups, but those earth patches are mounds of excavated soil made by solitary ground-nesting bees of the genus Anthrenes.  In the early summer the lawn is alive with busy adult bees. 
 
If the owners allowed the lawn to grow long, the bees would have to nest elsewhere, so having some variety of lawn management is a really good thing.
If you relax mowing, you will find some flowers soon appear, such as dandelions, clover and daisies, and others that also support pollinators.  Keeping a mown area around the edges and creating tidy paths through the long grass keeps it looking neat.  It is well worth trying some wildflower plug-plants in places where the grass won’t grow too long.  Cowslip is pretty tough and will spread.  You can also sow yellow rattle onto the cut grass in late autumn.  This annual is semi-parasitic and reduces the competitive growth of grass.
 
Wildflower meadows
 
These have become exceedingly fashionable among television and magazine pundits. There are few things more beautiful than a rough country meadow full of wild flowers in season, and unfortunately, they have become extremely rare.  However, there is real confusion in many people’s minds as to what a “meadow” is.
 
A true meadow is a permanent community of many species of grasses and perennial flowers but needs human intervention to survive without changing through time. Meadows are established by cutting and/or grazing, over many years. Having one would be a dream for most wildlife gardeners, but in the short term, establishing one is very challenging, mainly because typical garden soils are so fertile that grasses will outgrow and smother the flowers you are trying to encourage. If you can’t produce a low fertility area (for example by removing 10cm or more of fertile soil to expose subsoil, you really should not bother starting one from scratch.
 
A flower-rich true meadow on artificially raised ground near the river Thames. The soil is gravelly and drains readily, and is infertile. 
 
The meadow is managed by cutting, and has many plant species including orchids, and marbled white and small blue butterflies.
Relaxing mowing and introducing plug plants can help shift a typical lawn into something closer to a meadow, but you will need to keep working at it.  Another and easier approach is to create a cornfield flower patch which looks a bit like a meadow and is flower-rich and is very attractive to pollinators and people alike. They are sown as a grass-free mix into bare garden soil but will need to be weeded and re-sown at the end of every year.
 
We will be creating pages on this site about lawn, meadow and cornfield patch management, but for now your best source of summary information is Adrian Thomas’s excellent book “Gardening for wildlife”8. Another highly recommended book is James Hewetson-Brown’s “How to make a wildflower meadow”9 which also introduces the new technique of laying wildflower turf.
 
 
References
 
1.  Smith, C., Dawson, D., Archer, J., Davies, M., Frith, M., Hughes, E. and Massini, P., 2011. From green to grey; observed changes in garden vegetation structure in London, 1998-2008, London Wildlife Trust, Greenspace Information for Greater London, and Greater London Authority.
 
2.  Gaston, K.J., Warren, P.H., Thompson, K. & Smith, R.M. 2005. Urban domestic gardens (IV): the extent of the resource and its associated features. Biodiversity and Conservation 14, 3327-3349.  Available here
 
3. https://www.theguardian.com/lifeandstyle/shortcuts/2019/apr/24/why-you-should-turn-lawn-into-wildflower-meadow
  
4.  Thompson K., Hodgson J.G., Smith R.M., Warren P.H. and Gaston K.J. 2004. Urban domestic gardens (III): composition and diversity of lawn floras. J. Veg. Sci. 15: 371–376.   Available here
 
5.  Gibson, C.W.D.,  Hambler, C. and Brown, V. K. (1992).  Changes in Spider (Araneae) Assemblages in Relation to Succession and Grazing Management. J. Appl. Ecol. 29:132-142  Abstract here
 
6. Watson CJ, Carignan-Guillemette L, Turcotte C, Maire V, Proulx R. (2020) Ecological and economic benefits of low-intensity urban lawn management. J Appl Ecol. 57:436–446. Abstract here
  
7.  Lerman, S.B., Contosta A.R, Milam, J. and Bang, C.  (2018)   To mow or to mow less: Lawn mowing frequency affects bee abundance and diversity in suburban yards. Biological Conservation 221: 160-174 Abstract here 
  
8.  Thomas, A. (2017) Gardening for Wildlife. Bloomsbury Natural History pp 146-155
 
9.  Hewetson-Brown J. (2016) How to make a wildflower meadow Filbert Press Ltd.
 
 
Page written by Steve Head: Reviewed by Ken Thompson