I read that they prefer sandy soil with little nutrients. I have also heard people say to use compost, fertilizer, etc. I'm growing mine in 3 gal buckets and I'm wondering if I should use some sort of fertilizer in the soil or not? Thanks
Short answer is yes, you need fertilizer... Long answer is you need to check out the container garden thread because there is a lot more to know about it than anyone here can touch on. People like tapla have studied this stuff for us, to make it easy on people like us. If you really want to have a long term jalapeņo pot then theres where you start...
Should I use some sort of potting mix or liquid fertilizer or what?
Plants in containers will leach nutrients faster than plants in the ground, so you definitely should fertilize. You want something that doesn't have a high N (Nitrogen) content or you'll get lots of green and little fruit. A fertilizer with higher P (Phosphorous) and K (Potassium) numbers will be good. Personally, I use homemade compost at planting time then fertilize with fish emulsion as a foliar feed every week to two weeks (depends on the plant). I garden in raised beds so they are sort of containers;o)