What does rolling your lawn do to soil? Good soil consists of 25% air and 25% water. The rest is organic matter and minerals. The air and water are critical for plant growth. Soil will only have the right amount of air and water if the soil has proper aggregation. Aggregation is that friable lumpy type soil you find in forests.
Rolling the lawn destroys the aggregation and compacts the soil. Compacted soil contains less air and less water, making it much more difficult for roots to grow. Grass grows better without rolling.
The reason most people roll their lawn is because it is lumpy in spring. Frost has caused some soil heaving and moles dig tunnels making the lawn uneven. We want flat grass again.
The best way to deal with high spots is to wait until late spring, or even fall. Then dig out some soil from under the grass in the high spots. This will lower them for a flatter grass. The opposite process can be used for low spots. Use a flat shovel and lift the grass. Then put some soil under it. Add more soil than you think you need since the soil will compact.
Spots that are slightly low can be be top dressed with 1/2 inch of soil. You might have to add more soil every year for a few years to fill the holes left by animals. Don’t add too much soil at once since a thick layer will kill the grass.
Should You Ever Roll?
Rolling can be done directly on the soil when you are first installing grass seed to give you a level bed. But even this will cause compaction.
Some people roll newly laid sod which helps the sod come in close contact with soil so it can make roots.
Both of these applications should be done with a light roller.
Except for these installation steps – don’t roll your grass.
Editor of GardenMyths.com
I live in southern Ontario, Canada, zone 5 and have been gardening a long time. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3, 000 perennials, grasses, shrubs and trees. Yes-I am a plantaholic!