1. Choose a smaller variety if possible....i could not get hold of the smaller variety when i sow this.....got this seed from Tesco...no idea from which variety...my next carrot in pots project would be from Paris Market variety & the Purple Dragon variety...insyaAllah...
2. Choose a deep container to give em space to grow...mine is more or less 1 foot long..
3. Grow them in well draining potting media..u can read the links that i've shared below for more information on growing carrots in containers
because i'm too lazy to type...:P.
4. Pray a lot if u're an amateur gardener like me....LOL :P This is actually my 2nd attempt growing carrots... i've tried to grow carrots before....but i've failed miserably...because i feed those seedlings with way too much fertilizer after growing em in pots....this results in healthy carrots leaves with really tiny root...LOL :P
Read here for more info on growing carrot in containers :-