For many years I grew in pots and was very successful. My in ground raised beds I just dumped black kow into my raised beds nothing fancy and my peppers did great. I would say they grew slower in the ground but by the time they were putting on serious peppers and some were ripening they were just as large as they were in pots.

As for trough like pots I grew two plants in one, my biggest headache was it kept tipping over and unless its a really really large one its not worth it.

Good luck.

I only grow in pots. Plants in pots are easy to control and maintenance when they have problems.

I garden a little north of Concord NH so I'm a zone colder. I grown all my peppers in the ground but my beds are built using the lasagna method. Each spring I top off the beds with a layer of composted horse manure. I usually add additional fertilizer to the planting hole - maybe an organic mix like Cheep Cheep. We have a high water table. Doing lasagna beds is like a raised bed without lumber. They are best built the season before planting because they will settle/compost a lot over a winter. I never use Miracle Gro products since I can usually get free or almost free contents for my lasagna beds. You could remove the soil from your beds and do a base of composting materials. Try reading up on hügelkultur beds, too. You can start with tree branches to build mounds. I think the advantage of beds of any kind is you don't walk on them which helps compact them and you don't need a tiller. Sometimes I have a pretty fresh lasagna bed so I make a hole in which I add composted manure and soil so I can plant something like a transplant or a large seed like squash. When I transplant my peppers, I water well with a liquid fish/kelp fertilizer mixed with water. I may repeat a couple of times while the plants are getting established.

I grew some of my peppers in a high tunnel so due to the plastic roof, plants don't get much rain water except what maybe a little bit on the sides (sides are rolled up during the summer). This soil is drier than outside. We probably had similar amounts of rain to what you had. I don't think there's a big difference in how the plants responded to the rain or lack of it in the high tunnel. The high tunnel also heats up a lot with typical day time temps in the 90s.

I know a lot of pepper lovers like pots but I'm also concerned about how much fertilizer leaches out of pots during rainy weather. I've been in gardens where cucumbers in pots were noticeably less healthy than those in a nearby raised bed. I grow a couple of tomato plants in pots. They always need more water and more fertilizer. Was it really wet feet that held your peppers back or the need for more nutrients? I don't think there's enough using any one type of soil or fertilizer. Some of the lasagna layers are kitchen scraps. We have lots of worms that we didn't have before. What's your worm population like?

Good luck this next planting season.

People here grow chilies in the ground, and some of them get huge in two or three years, but we are in a frost-free zone. I don't know what the cold tolerance for chilies is, but I do know that they thrive with heat (I don't get much of that here) and survive well with cool (not freezing) temperatures, once established. I was unaware that some chilies could go dormant in the winter.

Right now I'm just trying to get seedlings repotted. I always seem to have trouble getting seeds started properly.

Lars, in his planting zone he would have to bring potted peppers indoors for the winter. There is information about cutting the plant back but I don't think it is necessary unless you have a pepper with a long maturation period such as the Caribbean seasoning types. But, I grew some in NH that had 100 days to maturity that were successful by starting seeds in February and keeping plants healthy until they could be planted outside around May 30.

I grow most of mine in double sub-irrigation 5 gallon buckets