I have a plant in my outside garden that produces purple/blue flowers that open in the morning and close at night. It also is spreading very quickly. I am trying to figure out what the plant is and how I can control it from spreading. It has deep hard roots.
Hard to say without a picture but it sounds like it might be morning glory. If it is among your garden plants you’ll have to pull/dig it out. If it is not, you can spray it with Kleen-up plant killer. Remember though that that spray will kill any plant it touches and should never be used in a vegetable garden. Always read and follow the directions on the package. If you can bring a bit of the plant to the garden center, we can ID it for you.