What size pots for my toms?

Just a quick question about my tomato plants. I mentioned a few days ago about them not growing in hieght anymore after they had a very quick growth ( more than doubling in hieght in approx a week ).

Could the reason they arent growing anymore be because the pots they're in are too small? The plants are about 18 - 20inches tall and they are in 6" pots.

Thanks

M Clark

What size would the final size ones be?

I remember my girlfriends dad growing tomatos in Cyprus, they were very tall with lots of fruit ( all down to the climate though ) but his were all in pots probably no bigger than 6-8".

M Clark

I use at least 10" pots.