So these inexpensive, pre-made trellises, from a big-box store, seemed perfectly decent to try. They're made by a company that has redwood in its name, but these are probably stained redwood color!
I'll be improving the soil beneath the three new trellises tomorrow, and planting more pole beans, cucumbers, and maybe a twining squash.
Eventually, we'd like to have permanent trellises on the side of the apartment building, but that will require a bit more investment and work!
