My little prairie plot (25 x 100 ft.) is in its fifth year. I have finally found someone to burn it but I wonder if the timing will be okay. We are adjacent to city land that is going to be burned sometime between April 12 and May 7, so my prairie plot can be burned at the same time. If they are here towards the end of that time, will that still be helpful and not harmful to my plants (native forbs and grasses)? I have a lot of non-native grass and clovers that I'd like to knock back.