I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
You did things right when you put in the beds. I am now having to wonder where that grass is coming from. Roundup works well so I doubt what you sprayed is coming back. Perhaps there are some grass seeds in the mulch. Anyway, I suggest you try a product with fluazifop or imazaquin as the ingredient at these are grass killers that are not as toxic to most broad leaved plants such as shrubs and flowers. This will prevent you from having to pull the new grass. I think you will be able to get things back in control much easier this way.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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