IanL,
In my opinion yes a soilless mix is best. With that being said my Mother started all her
seeds in garden soil for many years. That is all she had when she started
seeds in the 30's and never switched. The thing is she developed a method that worked and stayed with it. I also start tomato
seeds direct in the garden. But I'm also very sandy here so soil drains well.
Now to your question. First do you have any extra
seeds you can start in a
seed starting mix? If so I would start some in it and see how the others do. If not and you can find the
seeds it would probably be best to move them. I'm also assuming you don't have a lot of
seed starting experience so I would move them if at all possible. MG works well for me but any good
seed starting mix would work. Just my opinion. Jay