Q. I have a bumpy, uneven lawn and I’m told that top dressing will help sort it. Can I do it now and what do I need?A. Top dressing can be done in autumn and spring. You can order a large quantity of top dressing soil online to be delivered, such as Rolawn, or buy it in 25kg bags. If you are smoothing the lawn you can apply at 3 to 4 kilos per square metre but don’t smother the grass, keep 75% of the leaf exposed.