The short answer to this question is – as often as possible!!
Rain and wet ground can make mowing tricky, so it’s important to mow your lawn whenever the weather is good. And take every chance you get – it only takes one week of rainy weather on top of a week you could have mowed the lawn but didn’t, for your lawn to quickly get out of condition.
Of course, it depends on the weather and dampness of grass and soil whether or not you mow your lawn:
When the ground is wet, try waiting until the afternoon and check again – often times, the ground will be dry enough later in the day to be mowed.
If the ground has been very wet, or the weather has been particularly cold (or dry, for that matter!), cut the grass on a higher setting as growth is likely to be slow.
When the grass begins to grow more quickly, the set the mower to cut lower down.
And remember to watch for turns – often the edges of gardens can be wettest, so you want to make sure to lift your mower so that pressure is reduced on more vulnerable ares.
So what happens when the weather turns very warm? Being May, we know this could happen any moment (although it’s a chilly 11deg today!). But when the weather does become more consistently hotter and drier, you need to think about retaining moisture in the soil.
Do do this, mow your lawn as high as possible, by adjusting the setting on your mower. Longer grass protects the soil by creating a protective barrier between the sun and wind, thus prevents excessive drying and keeps the soil moist. It also keeps the soil underneath cooler (this is why it’s so lovely to go barefoot in the garden in summer – it’s actually great for cooling us down!).
Grass – much like much vegetation – is nearly all water, so if you cut the grass too short, you will remove a lot of water. Not to mention that the longer the grass, the more dew it collects. In May we often have cooler nights still, so dew can really increase at night during this month – think of it as cost and labour free watering for your lawn.