Hello Marco, I’ve grown a few peppers in pots at work in Landenberg pa which is very near Longwood gardens. They love standard potting soil amended with whichever goodies you like to add, in black pots in full sun. If you don’t give them tons of fertilizer and start and keep them in smaller pots they will be smaller than in big nursery pots with lots of feed. A nitrate cal mag fertilizer would be better than ammonium type, again to help keep smaller and sturdier. To germinate easier, make the soil hot
. Starting in small plugs, plastic dome covered, in full sun, and even with heat underneath when the sun isn’t out, will help kick them to germinate. Once fall temps start getting below 60, you could move them indoors for overnight, and then indoors with as much light as possible until room temps outdoors are present again. When moving indoors don’t let them be too wet, a little leaf flagging is better than too wet at this time
When I was still living in upstate ny Utica area I’d started an orange bell pepper plant into a rectangular window pot/tray but rainy weather kept it from growing, so I brought it indoors for the winter, and put it back outside when it warmed up again. It lived and made a few peppers next summer. Being in a small pot and not feeding when it was cool/dark helped keep it smaller, along with using cal mag nitrate fertilizers helped prevent too much growth
This last summer at work in big black pots I had newmex green chiles, Cajamarca, shishito, jays peach ghost scorpion peppers growing quite happily.