I have some sunflowers, that I want to put in pots, whats the best size?
Also, should I just pot on into the next suitable size container for the seedlings or just pot in its final pot?
Does the packet say what variety they are and how tall they grow? When I grew them in pots they kept blowing over on windy days, so I would suggest you weight the pots. If they are tall ones I would want the pot to be at least 50cm wide.
I would plant them up now.
This year I have sown Dwarf sunflowers as I want to put them into pots. These don't grow very tall so I hoping they will be ok in pots. I got the seeds from Lidls and they are growing on very well. I usually pot mine into the next size container when they are still seedlings then when they are big enough I put them into their final pots. Good luck.