Q.redoing my garden
Do I need to kill/remove all the roots from perennials when redoing my garden? My 11-year-old flower garden has gotten way out of control. I have dug up the entire garden, moving the plants I want to keep to another garden for the winter. My question is this: most of my plants were perennials and have spread wildly and widely. When I dug them up, I was left with LOTS of roots in the soil. I have turned the soil with a spade, leaving a lot of them open to the sun but, obviously, lots of them are still buried. I’m afraid if I don’t get rid of them somehow all the perennials will just come back up. Is there a way to remove/kill them all off before I replant or shouldn’t I worry about it?

Digging, pulling and raking is necessary to remove the old roots and clean up the garden.
It certainly can be a lot of work, but the more you remove the healthier the garden will be for the new plantings.
Here is a link with more information.
https://www.gardeningknowhow.com/garden-how-to/projects/removing-existing-plants.htm