Lawn Care in Summer

Whether the summer brings a heatwave or a downpour, your lawn has a lot to contend with. We show you the most effective ways to protect it.


How to water your lawn when temperatures are high


Watering your lawn is one of the most important maintenance measures to consider all year round, and particularly in summer when there is often little natural rainfall. As a rule of thumb for lawn care, you need to supply approximately 20 to 25 l of water per square metre per week – depending on sunlight, heat levels and wind.


How much water does my lawn need?


If you’re an amateur gardener, you’ll need to use more than you probably expect. In general, lawn maintenance in summer means supplying each square metre of your lawn with 20 to 25 l. However, it’s important to remember that overwatering your lawn can also be harmful, as it displaces air from the pores in the soil – which can cause root rot. Take a sample from your soil and have a sniff of it: if it smells bad or is grey-blue in colour, it’s highly likely to be waterlogged, suffocated and in need of care.


Tips for watering your lawn in summer

  • Once a week is enough for watering in your summer lawn care schedule, using approximately 20 l of water per square metre each time. This amount should be varied to account for the specific site and weather conditions.
  • Clay soil: clay-rich soils are prone to baking hard in summer, so may need a little additional care. If your soil cannot absorb the full volume given in one go, water more lightly but twice in quick succession (or on the next day), and then don’t do it again for a week.
  • Make sure you are watering evenly. When taking care of your lawn, the last thing you want is for summer heat to cause dry patches – you can use a soil moisture meter to check that the lawn is sufficiently hydrated all over.
  • Do your watering in the early morning or late evening, as strong, direct summer sun can scorch a damp lawn.
  • If you have trees, shrubs or hedges growing around your lawn, increase the amount of water you give it.
  • In the extreme heat that can occur at midsummer, your lawn needs extra care: increase your watering frequency to two to three times a week, in the early morning or in the evening.
Close-up of a well-cared-for green lawn in sunshine


Checking the moisture of your lawn


In a dry summer it becomes an even more important part of your lawn care routine to know that the lawn is getting enough to drink. If you don’t have a moisture meter to hand, you can check by placing a number of jam jars in various locations in your garden: there should be around 2 cm of water in all the jars after rain or watering, if the grass has received enough. From this, after some trial and error you will be able to gauge water needs perfectly so your lawn need never be stressed by the summer heat, and you can give it the right care just when it needs it.

Another method is to insert a strong blade or spade into the ground to extract a sample of soil to a depth of around 10 cm, in several places; in a well-watered lawn, in summer the deeper soil should be damp (not wet) and the top 1 to 2 cm should feel dry – it should never be the other way around. If the sample is damp on top and dry underneath, the water is not getting to where it’s needed.


Common mistakes in summer lawn maintenance


When it comes to watering in summer, the most common mistake is doing it both too frequently and insufficiently deeply each time. Many people have a schedule for lawn care that involves giving their lawn a light watering every evening during the heat of summer – but this causes longer-term problems. That’s because it is mainly lawn thatch that gets dampened if you do this, along with just the top few millimetres of soil in the best-case scenario; over time the grass responds by concentrating its roots close to the surface of the soil, making it particularly vulnerable to summer stress. Another effect is that lawn thatch will quickly build up and start to dominate, because it prevents any moisture from reaching the soil underneath – so the lawn keeps drying out. The lawn is now unhealthily “addicted” to moisture, and after just a few summer days of not watering, it will quickly turn yellow and need extensive care, as well as being much more susceptible to fungal diseases.

Common mistakes in summer lawn maintenance


When to mow your lawn in summer


Your grass is at the top of its game in early summer as it comes out of spring, and so it will be bursting with strength and growth. That means your lawn care schedule can certainly include mowing every four to seven days when summer begins. In fact, such regular mowing encourages your lawn to grow more densely, by stimulating the grass to develop new side shoots – though keeping the grass at the right height is actually more important than the frequency of mowing.


What lawn height is best in summer?


The height to which you cut the grass is a key factor for great lawn care results, and it needs to be adjusted as temperatures increase. The higher the summer heat, the longer you should keep the lawn, mowing to 4 to 5 cm in sunny positions, and keeping it at 5 to 7 cm in shadier areas. At the same time, take care to avoid cutting off more than a third of the height each time you mow, in order to prevent unattractive scorch marks and blemishes on the lawn. Always use sharp mower blades and ensure that the ground is dry.


STIHL multi-mowers offer superb cutting precision


If you’ve neglected the lawn care for a while by the time summer arrives, you may need to mow the grass in multiple passes, initially using the highest possible cutting setting and then a lower one. All STIHL multi-mowers feature a convenient cutting height adjustment option so that you can set the right cutting height for your lawn.

A large area of green grass with tall trees in the distance, a dry stone wall in the background, and a rustic wooden fence in the foreground


How to feed your lawn in summer


By the start of summer, the nutrients from the spring fertiliser application have almost been used up. To best care for your lawn through the season of boisterous football matches and barbecues, we recommend you fertilise again at the start of summer. In fact, even lawns that don’t see this sort of traffic can benefit from a vitamin boost right now, as frequent early-season mowing means many of the nutrients in the grass will be lost in the cuttings, which puts a lot of strain on the soil in the long term. That’s why it is so important to return vital nutrients to the lawn in summer, and the best way to do it is by applying a mineral lawn fertiliser.


The right summer fertiliser


When choosing the right fertiliser for your summer lawn care, it needs to contain these essential ingredients for keeping your soil and lawn healthy:

A grassy plot with a treehouse, green garden table and chairs, and mature trees in the background
Active ingredient Description
Potassium (K) Increases pest resistance, regulates plants’ metabolism
Phosphorus (P) Supports chlorophyll formation during photosynthesis and ensures that the lawn is a vibrant green colour
Magnesium (Mg) Supports chlorophyll formation during photosynthesis and ensures that the lawn is a vibrant green colour
Calcium (Ca) Encourages cell division and therefore the regeneration of all parts of the plant. Stimulates lawn growth
Nitrogen (N) Encourages cell division and therefore the regeneration of all parts of the plant. Stimulates lawn growth

It’s important for these minerals and nutrients to be present in the appropriate concentration; alongside plenty of nitrogen for growth, magnesium and calcium are required at higher levels to ensure that your lawn can withstand both extreme heat and summer storms.


Lawn care tips for feeding your lawn in summer


  • Get the feeding in early. You should ideally fertilise your lawn in June to prepare it for the hot summer ahead.
  • Promote dense growth by using slow-release fertilisers; with these, the grass grows slowly through the summer but becomes thicker and more resilient.
  • Use a sprinkler system – this makes it easy to water the lawn generously but carefully after fertilising.


Summary: Lawn care in summer

  • Water liberally once a week, at a rate of at least 20 l per square metre
  • Flattened patches of lawn may indicate insufficient hydration
  • Take care to regularly check your lawn’s moisture levels and adjust watering requirements accordingly
  • Mow your lawn at least once a week in summer, reducing the length of the grass by a third each time
  • The grass should be cut to around 5 to 7 cm high
  • Fertilise your lawn in June to prepare it for peak summer heat


How often should you feed a lawn in summer?

In summer you should feed your lawn once, quite early in the season to prepare it for midsummer high temperatures. June is generally a good time to apply a specially formulated mineral fertiliser.

What height should the lawn be cut to in summer?

The height the lawn should be cut to in summer is between 4 and 7 cm; the exact height depends on whether the lawn is in a shady position or exposed to the sun. During hotter weather, keep the grass cut slightly higher, as this makes it more resistant to heat stress by encouraging deeper roots.

Can you scarify a lawn in summer?

You should not scarify a lawn at the height of summer. If it’s not too hot in late August, the grass may recover well after scarifying, however we recommend waiting until even later in the year, or ideally scarifying in spring. The grass needs to be in growth and the soil not too dry.

How often should you water a lawn in summer?

How often you should water a lawn in summer depends on the weather, with once a week generally sufficient, though when temperatures are really high it could be as often as 3 times a week. Use 20 to 25 l per square metre, and remember that watering less thoroughly but more often makes your lawn vulnerable to stress.