I was wondering if one of these sunflower seedlings would take and carry on growing successfully if I transplanted it into another pot, or do I need to be ruthless and get rid.
yes , if you transplant those seedlings they will grow successfully in another pot or in ground too. they grow happily without much fuss. when I grew them some of them grew taller than 10 feet in height.
No problem, just pot up........
west central Scotland
I would pot them too - but not in anything too big - maybe a 4 inch pot just now. Anything much bigger and they can get a bit lost until the root balls are big enough to support the top.
It's a place where beautiful isn't enough of a word....