Q.will poppies take over garden
Will my poppies eventually take over the grass in the garden? I have gorgeous poppies – lots of them, more every year. I also have lots of ugly grass growing between all the poppies. Eventually, the grass is taller and the poppies are dormant, and it all just looks bad. How can I get rid of the grass without hurting the poppies? We moved into this garden, it’s not one I planted, so I’m really not sure what to do other than to dig it all up and re-plant next year, but I really, really, don’t want to do that!
Weeds among poppies can be an issue, especially in your case where it was not cared for.
Poppies will spread but in your zone 4 garden you will likely lose some each year also, so a takeover is not likely.
You can try planting other flowers among the poppies to help you fill in the garden after the poppies are done.
A ground cover that will help suppress weeds could be quite attractive.
Either way it's some work ahead for you.
Best of luck!
https://www.gardeningknowhow.com/ornamental/flowers/poppy/growing-oriental-poppies.htm