Posted: 28/06/2016 at 22:30
I just put my hand over the soil with the stem between my fingers, turn the pot upside down and gently slip the pot off from the roots to see if they're ready to re-pot. Usually you can see roots appearing in the holes at the bottom of the pot too when they are ready. To overwinter, I only water them when the top inch of compost is completely dry (stick a finger in to tell) and then only enough to dampen the soil. In the spring there will just be a (hopefully) green stem left with some dead bits. Cut the brown bits off and water them. Don't water again until you see signs of growth. At that point I take them out of the pots and shake off most of the old compost and repot them into damp fresh compost. It doesn't always work but after a mild winter like the last one you can get an amazing head start.
They do well in smaller pots, much better than tomatoes would. You'll get less fruit per plant of course but in the case of chillies in particular that isn't a big deal as a little can go a long way!