Q.Can dead grass be a good thing?
I live in Ottawa, Canada (zone 5a). My grass lawn died entirely last year and as the snow melts, a muddy brown messy is being unearthed. This year, i am planning to have flower gardens in place of the lawn. I am wondering about what prep to do to the area. It has been recommended to me to remove the dead grass and bring in fresh soil. But I wonder if the dead grass, after a winter under snow, might make suitable compost if I leave it instead. What should I do to prepare my yard for a flower garden at this point?
I am a first-time gardener so please expect my knowledge base to be less than you are imagining.
Grass that inexplicably dies needs investigation before you proceed. Do you have a severe grub infestation? Is there any chance of a toxin in the soil? Does the area drain poorly? Is the pH way out of whack? Making sure there isn't an underlying problem is step one. Step two is to get a soil test. You can't know how to improve your soil without knowing what the current soil is like. Correcting deficiencies or off-kilter pH is much easier when done before planting. If you are growing flowers from seed, rake the dead grass first. You can use it as mulch after the plants emerge. If, while raking, you see evidence of emerging grass that will have to be removed. Flowers have a wide range of requirements; there is no one-prep-fits-all for flowers. Many gardeners add several inches of compost and peat moss, either dug into the entire bed or into the planting hole and surrounding area. Some plants, lavender being a good example, must have sandy, loose, dry soil. Adding peat moss is likely to kill lavender roots because it keeps soil damp too long. Cluster plants together that prefer dry soil so you can easily avoid over-watering them. If you are growing native plants, no peat moss is needed. These plants have adapted to the soils in your area. So please start with an investigation into what killed the grass so the same doesn't happen to your flowers. You may find one of the 2 links helpful for soil testing in Canada. https://foodsecurecanada.org/sites/foodsecurecanada.org/files/guide_for_soil_testing_2013.pdf
http://www.omafra.gov.on.ca/english/crops/resource/soillabs.htm
