Last year was the first year I grew tomatoes. Overall, it went pretty well, and the plants were reasonably prolific. I haven't started anything for this year, and if I decide to, I know I have to do it soon. Here's my question: I have the pots from last year, with the soil still in them. Do I have to change the soil if I buy new seedling plants, or can I just use the pots with last year's soil? My perennials (mostly herbs, but also a small Alpine strawberry plant, which is already almost fully grown in terms of leaves and some blossoms) are doing fine in their old soil, but I don't know if tomatoes are different.