I tried to grow a green pepper a number of years ago, but didn’t succeed very much. The summer in the UK at the time was pretty poor and I didn’t have a green house. Last year my mother succeeded, due to a warmer summer and having a small green house to put it in on colder days. This year we are having a fantastic summer in the UK and I have taken one of my mothers slower growing peppers to see if it will grow any quicker in my garden, as my garden is a bit of a sun trap. I also have a small cheap walk in green house to put it in, if the weather drops.
I will let you know how I go on with growing a green pepper.
Keep the pepper well watered and warm is the advise I will give to you. Ensure that the plant drains through a hole in the bottom and I have used compost to grow it in.
I have also taken the seeds out of a green pepper I purchased, to see if I can grow some green peppers from seed next year.
All the best