Grass can be really stressed by poor mowing practices! A newly cut lawn looks great and the all-familiar summer smell of shorn grass brings many of us back to our childhoods and those long summer days, but for your lawn, it truly is a stressor.
Cutting your lawn damages and ruptures the elements of your grass plants. Literally shearing off entire sections, the cutting of leaf tissue can cause major loss of water, the introduction of disease organisms into the open “wound”, and the disruption of photosynthesis due to a loss of carbohydrate production.
Mowing height is a compromise between getting the superb looking lawn you want and allowing the grass enough leaf to be healthy. This means you can mow your lawn close but only when optimum conditions prevail; warmth, moderate sunshine, moderate rainfall and adequate fertiliser. This is also when the grass is healthiest and able to recover easily from regular low cutting.
Change these conditions to high-stress ones; heat, drought, cold or constant drenching and your lawn will need high mowing to survive. Having said that, there is no other plant like turf grass that can handle this kind of regular trauma. Being the caring homeowner you are, the natural question is “how can I make this as painless as possible”? So nice of you to ask!
Use the Rule of 1/3 when Mowing your Lawn
The ideal height for your grass will depend on a range of factors including:
- Location – shade/full sun/slope
- Grass Varieties
- recent weather
- Frequency of use
- How it& is used
Your aim should be to cut off less than 1/3 of the grass-blade. With an optimal length of 3 – 5 cm for the average domestic lawn in the UK, this means never allowing your lawn to get long enough where you must cut off more than 1/3 of its length to get it back down to optimal height.
(Quick math question: Your lawn is at 7.5 cm, but optimal height is 4 cm. How much do you mow? No more than 2.5 cm (1/3) at a time. This will bring it only to 5 cm, but that’s OK…wait until it’s at 6 cm and then mow back down to 4 cm.)
If you get lazy at the start of the mowing season while the grass is still active and it gets too long, mowing off more than 1/3 of the turf to get it down to its proper height will have a more negative impact than you think. Root growth will delay as the turf puts all resources into healing the tips leading to decreased or stagnant growth. Allowing this cycle to continue will make your lawn more open to weed, disease and thatch invasions.
Develop a Mowing Strategy
If you know your lawn is going to get away from you due to holidays, extensive rain or mower issues, it’s best to get your lawn back into shape with short, frequent mowing until it gets back to optimal height. If it takes 2-3 cuts in the same period you would have usually mown once, so be it. Your lawns long-term health will be worth the effort.
Mowing Tip: The worst time to mow is in the heat of the day when the sun is at its peak. The intensity only adds to the stress of the mowing, so with that in mind try to mow early in the day or in mid-to-late afternoon.
So What Does This All Mean For My Lawn?
Let the weather and seasons be your guide to mowing heights. Three fingers, just like the ‘W’ of weather can help you remember your mowing heights as follows. Using a low-use ornamental lawn as an example for mowing height:
- Raise height for the start of spring – the first upright of ‘W’ e.g. 4 cm
- Lower the height as things warm in spring – the first bottom point of ‘W’ e.g. 2 cm
- Raise again for summer if dry – the middle point of the ‘W’ e.g. 4 cm
- Lower again as growth picks up in early autumn – the second bottom of ‘W’ e.g. 2 cm
- Raise again for the last few cuts of the year – the last upright of ‘W’ e.g. 4 cm
Guideline lawn mowing heights
- Ornamental lawns with no ryegrass 1 to 2 cm
- Low use lawns with or without ryegrass 2 to 4 cm
- Heavy use ryegrass lawns 2.5 to 5 cm
- Shady areas add 50% to the lawn mowing height
- Slopes dry faster so if possible add 50% to the height
- If you have moss in your lawn mow at least 1.5 cm above moss height
- In times of stress – extremely wet or very hot and/or dry then mow as high as possible
- If in doubt mow high
So Realistically How often?
Mowing by height is undoubtedly the best regime to follow but what does this equate to in a typical year. A typical annual lawn mowing service and edging programme might follow the following regime:
- Winter (December/January/February): “It’s had its last cut of the year” is a phrase we hear a lot when the temperature drops in winter. Although grass is dormant in the colder months it does grow albeit very slowly. Try and do a light high cut (topping) and to undertake any leaf and other debris clearance. This will keep the lawn looking smart, after all, there is no reason to have a ‘scruffy’ looking lawn for one-third of the year.
- March/April: Growth starts in earnest as the temperature rises, increase the mowing frequency to every two weeks.
- May/June: This is peak growth period for grass, further increase the mowing frequency to weekly cuts
- July/August: Mowing frequency will ultimately depend upon the weather.
- If dry and hot, growth will slow and it may be possible to reduce the mowing frequency to every two weeks.
- If we have a wet summer mowing should continue bi-weekly
- Autumn: (September/October/November) Again a lot depends on the weather but mowing frequency is gradually reduced to the point of only three-weekly visits.
A Final Word
“Keep those mowing blades sharp”
A final, final word
If this all seems either too complicated or just a little too much effort Contact Us about our Professional mowing service