Get them in the pot now. Mine are already over a foot high, and yours will be ok.

They will be fine in a pot,Lizziebee..I grew some in pots for the first time last year,and they are above the soil again now....not as tall as Cammomiles yet,but I'm much further north..I put a stake next to each one ,and I planted three to a biggish pot.as they grew really big,and were tending to lean over..they definitely needed some support..

Thanks for your answers, I have planted them in a pot and 2 were sprouting anyway, so time they were in.