Loosening and turning over the soil is useful for managing weed populations, but tilling should be performed with caution. Tilling may simply rotate weed seeds. Hartzler explains the advantages of tilling.
“It provides a clean start for the crop and simplifies weeding. It can bury a lot of seeds at depths where they are unable to successfully establish. This can be a real benefit if a lot of seeds were produced the previous year and are laying on the surface,” he said.
However, dormant weed seeds may be brought back to life with tilling.
“Seeds buried more than three to four inches deep are much more persistent since there is a lot less biological activity at this depth. The next time the garden is tilled, some of them will be brought to the surface where they can germinate,” Hartzler said.