I bought two jalapeno plants from my nursery and they are in the same pot. I live in the Northeast (like you). I have soooo many of them now. They just grew! I just put potting soil in the pot, and water them. There have been a few days when I forgot to water them, but they are resilient and have produced lots of beautiful, green guys
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I think my pot is about the same size as yours as well.