Defect Avoidance Guidance - Contaminated Topsoil

Here is recent issue our soft landscaping division encountered, how it could have been avoided and what we did to deal with it.

We were recently asked to return and have a look at a garden we landscaped for a house builder client. A fortnight after turfing the rear garden, large weedy leaves started appearing through the turf. After examining the leaves closer, we established they were dock leaves. We undertook some trial holes, digging down to find out where the roots were coming from and we found out they were coming from the sub soil.

What had happened was the original topsoil levels were too low, but that the weed growth, that had accumulated during the construction phase wasn’t cleared or treated prior to new topsoil being applied. This meant the weeds grew healthily through the new topsoil out through the fresh turf.

The method of treating this is by applying a selective weedkiller to the turf. The selective weedkiller, selects the broadleaf weeds such as the dock leaves to kill, leaving the grass behind. As the docks are notoriously strong weeds, it will require several treatments to eradicate the weeds entirely.

This issue could have been avoided by treating the weed growth properly prior to installation of the topsoil.

If you would like assistance with your soft landscaping scheme, please do not hesitate to get in contact.