This is what I would do....   The longer they grow together the harder it is to separate so I would act as soon as possible.  I would put a very slow running garden hose beside them and totally saturate the area with water.  Then when all is muddy I would take small garden shovel and start to pull and work them apart, I then would put each  in a pot with potting soil and soil mixture.  Then take all the pots and put on a small trailer that I could manipulate to what they need for a few weeks.  Like pull to shade if too hot, water daily,  maybe miracle grow in couple of weeks and then I would plant the seedlings this fall in final destination.