University Parks gardeners save LMH lawn from insect attack

‘I just wanted to let you know how pleased we are with the works your team carried out for us over the last couple of weeks. Their hard work and attention to detail were very much appreciated, not just by me but by other members of staff who could see the work progressing from their office windows. I received much positive feedback from colleges staff who were pleased to see the works completed so well.’ Kate Hunt, Head Gardener, Lady Margaret Hall


The challenge

University Parks gardeners were ready to help out in autumn 2017 when the lawn of Lady Margaret Hall (LMH) suffered a damaging and unsightly infestation of chafer grubs.

Chafer grubs are a regular threat to lawns across much of Britain. In large numbers they are a very serious problem; they feed on the roots of grass, weakening and killing it, and are also irresistible to animals like birds, foxes and badgers, which rip up the turf to get at them. Milder winters may be making the problem worse, as more individuals survive the cold months to breed anew in spring. To compound this, tighter regulation of pesticides means these can no longer be used.

In autumn 2017, some 1,200m2 of lawn at LMH was showing the signs of chafer grub infestation. The college has its own gardeners but decided to call on the Parks team’s help because as a large team they have the capacity to carry out such a large job quickly, as well as access to specialist machinery such as mini-diggers that allow large amounts of earth to be moved swiftly, tractor-mounted rotovators that let a single person till a large area of ground and box rakes that make it easy to level soil and break up any lumps.

The solution

The Parks team started by digging out and disposing of the affected soil and turf. They sprayed the whole lawn with weedkiller to deal with perennial weeds, rotovated it, raked it flat, compacted it, dressed it with fertiliser and new topsoil and finally re-seeded it with a suitable grass mixture. Most of the grubs were removed with the soil, but even those remaining were set back severely by the disturbance to their environment, particularly since the Parks team left it a week or so between rotovating the area and re-seeding it, enabling birds and other predators to get at the grubs.

They used a mixture of new technology and tried-and-tested old methods – for instance, in levelling and compacting the lawn’s surface they used both modern box rakes and the more traditional approach of raking by hand and then carefully treading the earth down.

The result

The whole project lasted around three weeks in early October 2017 from start to finish – a total of 32 person-days’ work. Unusually good weather meant the newly-sown grass was soon growing strongly and was well established by the following year. Parks staff were in regular contact to provide advice and ensure the young lawn continues to thrive, returning in spring to re-seed any areas of thin growth and carry out the first few mowings of 2018 before handing over to the college staff. LMH staff were impressed by their work and the benefits it has already brought.

This kind of work has been much in demand lately; earlier in 2017 Parks staff re-turfed the main lawn in All Souls College after a chafer grub attack. ‘We have a lot of experience with lawns, with all the work we do looking after them for colleges,’ says Area Supervisor Matthew Currie. ‘Here we were able to use that expertise to help our colleagues at LMH. We’re always looking to improve our lawn care, so we now offer more services beyond just mowing to external customers – for example we can take care of feeding, spiking and aerating, which help lawns stay healthy over the long term. There’s no way to stop chafer grubs completely but the healthier your lawn is, the more chance it has of fighting them off.'

LMH lawn Before and After