Did you know that every given square foot of soil has between 900-3,000 dormant weed seeds?!
If you're tilling a lawn that's been mowed for years, chances are your weed seed count will be on the lower end. The first pass can be done at the deepest depth of 4-6", with a shallower tilling of just 2-3" the following times.
If your area has been an old field that has grown and seeded itself for years, expect plenty of weed seeds in the soil. In this case, it is best to shallow till 2-3” deep two or three times over the course of several weeks rather than till deeply. Allow 2-3 weeks between each soil turning, so the weed seeds have time to germinate before you till. Then, remove the weeds, plants, roots, and debris before sowing.
Avoid any temptation to dig deeper than recommended: the deeper you dig, the more dormant weed seeds you'll turn up onto the soil’s surface, where they can sprout faster than your wildflowers.
Careful rototilling works well for three reasons:
- It opens the soil and allows a "soft" space for emerging flower plants;
- It creates a good seedbed for germination and promotes good "seed-to-soil" contact; and,
- it removes almost all the existing grasses and weeds which would otherwise compete with your seedlings.