'Common' lawn mistake could damage your grass and ruin your garden (2025)

Michael Griffiths, who boasts over 4 million followers on social media, has shared a common lawn mowing mistake that people make - and how it could damage your grass

It's that time of year when those with a passion for gardening are itching to rev up their trusty lawn mowers - but a word of warning comes from one garden pro who warns that an overzealous trim could harm your turf. A recent study pinpointed March as the month most Brits embark on the inaugural grass trim of the year, gearing up for the warmer months.

But for those who haven't yet dusted off the mower, gardening expert Michael Griffiths is advising against "scalping" your grass to ensure a green lawn come summertime. Scalping the lawn, a technique aimed at spurring growth by cutting the grass very short, clears away dead grass, thatch and debris while allowing the soil to heat up more quickly.

It typically involves setting the mower to its lowest notch, but Michael warns that scalping in April could leave your lawn vulnerable to drought and weeds.

On TikTok, where he posts as @themediterraneangardener, the lawn expert warned: "Spring's here, but don't start scalping your lawn.

Try to keep your grass the same height throughout spring and avoid mowing it too short as that can make it more susceptible to drought and weeds, and moss can take hold."

He further advised that the sweet spot for most lawns is about 4cm high, while areas in the shade should be kept slightly longer, between 1-2cm higher.

You can tweak your mower settings accordingly, but Michael recommends holding off on mowing new lawns until the grass reaches at least 5cm in height.

The Royal Horticultural Society (RHS) advises that grass should be maintained at about 4cm tall during spring, autumn, and winter, while in the summer it's best kept at around 2.5cm.

For those with finer lawns, the RHS suggests keeping the grass even shorter, between six to 13mm.

A gardening expert has recommended that it's time to put away your autumn lawn feed, which is high in phosphates, and switch to a nitrogen-rich lawn feed to encourage top growth.

According to Lawn Solutions Australia, nitrogen is crucial for vibrant green grass as it aids in the "formation of proteins that the cells within the grass need to grow".

Michael, another gardening aficionado, shared additional essential tasks for spring, such as feeding and pruning roses to ensure "better blooms", transplanting forced blooms into garden borders, potting lilies and other summer-flowering bulbs, and tackling weeds before they become established.

His followers were quick to engage with his lawn care tips, with one commenting: "Just saw a guy with a nice lush lawn with some good growth absolutely sculpting it to the ground, his mower was struggling. I was wincing."

Michael replied, warning: "Eeeshh - not good. Really common though."

Another follower chimed in with their own advice, cautioning: "Don't go too high in nitrogen though as you'll promote thatch build up. Also a bit of iron to kill off any moss and a light scarify."