I grew twenty jalapeno peppers in pots in my first year of apartment living, all descended from a pepper I had in my window in college. Any container can be a plant pot as long as you can add drainage holes - I used a lot of milk jugs and soda bottles cut in half, with old takeout trays to catch the drainage water. Soil is cheap (or free if you’re not picky about what’s in it) and I just watered them with tap water. Ten years later I have fewer peppers but I still have one from that lineage, and my spouse has over two hundred plants in pots scattered through our apartment. We use water from the fish tank as fertilizer, and our main expense is a spritzer of insecticidal soap bought every year or two, and thrift store teacups I drill drainage holes in for some of the succulents. Time and the energy to care for plants are probably the biggest hurdles when you’re broke, but money isn’t necessarily a huge barrier. I hope that helps.

i mean tons of people live in houses with massive yards, for them it’s effectively free.