Posted: 22/03/2013 at 22:01
Hello Kate,all i can say it that I dug up a lot of the lawn for beds last year and I did very little in improving the soil at that point and my plants did really well.
I wouldn't spray any areas, there maybe some good things growing as well. I do use weedkilller, i tend to paint it on selective invastive weeds later in the year. I think these chemicals can have a longer term effect in the soil which affect the plants.