Mowing your lawn is something you will do many times throughout the course of the gardening year and with that in mind it is useful to have an idea as to how long your grass should be, given the variety of different grasses available and the seasons in which they will grow.
The most important aspect of mowing your lawn is not to cut the grass too short.
Cutting the grass too short leads to poor root growth and that in turn leads to poor leaf growth. Leaving your grass at a reasonable length is a good way of preventing rough grasses such as crabgrass taking hold.
The rule of thumb is not to remove more than one third of your grass’ height in any one mowing. The best way to achieve this is to mow your lawn – in the summer months for example – once every three to four days – this allows for regrowth and ensures that as you cut the lawn back you are not cutting away too much and stunting its growth.
Below are a list of the most common grasses to be found in gardens in the United Kingdom and their recommended cut lengths:
- Bluegrass – When it reaches 7.5 cm cut back to a height of 5 cm
- Ryegrass – When it reaches 7.5 cm cut back to a height of 5 cm
- Fescue – When it reaches 7.5 cm cut back to a height of 5 cm
- Tall Fescue – When it reaches 7.5 cm cut back to a height of 5 cm
- St Augustine – When it reaches 7.5 cm cut back to a height of 5 cm
- Buffalo Grass – When it reaches 7.5 cm cut back to a height of 5 cm
- Bermuda – When it reaches 5.5 cm cut back to a height of 3.25 cm
- Zoysia – When it reaches 5.5 cm cut back to a height of 3.25 cm
- Centipede – When it reaches 5.5 cm cut back to a height of 3.25 cm
During periods of dry weather it is advisable to cut your grass slightly longer so that it allows the soil beneath it to retain water, longer grass ensures that it takes longer for the sun in dry spells to evaporate the water content in the soil, thus allowing it to last longer in conditions where it may not be possible to water it such as in the event of a hose pipe ban.
When cutting the grass at any time of the year it is important to remember that although the grass looks healthy and may well be healthy, the cutting of the grass has a definite effect on the root system beneath the soil so special care must be taken to ensure that the grass length is conducive to sustaining healthy roots.
When you have mowed your lawn it is wise to scarify it and remove as much of the dead clippings as possible so as to avoid a build up of Thatch, which – as we have discussed already – can lead to fungi and other lawn diseases.