Pineapple is easy. Just use any three to five gallon container. Whatever you like. The first one I grew is two years old. It's in a five gallon container with three mini roses. Its three foot wide and at least a foot tall. We only get one month of summer - August so it's starting to get a growth spurt as the weather hits 80. Hoping for my first homegrown pineapple this year. I have a bunch of first year ones in three gallon containers and they're getting more sunlight and double the size in a few months. Just bought a couple and placed them in a 20 gallon container with herbs and strawberry.

I had a similar experience last year with my peppers. They did miserably in the raised bed, and really well in the containers. Tomatoes in containers also out performed my raised bed ones. I was using MG potting mix in the containers . But I had the opposite experience with cucs. They did better in the raised bed. My tomatillos also did amazing in the raised bed. I realized this year (before starting my Year 2 veggie garden) that the reason for this inconsistency was 1) watering, 2) fertilizing and 3) my raised beds were new (triple mix, mannure, top soil).4) planting temps I was over watering everything. Basically not letting soil dry out a bit. Which caused a lot of problems. I didn't think I needed to fertilize the raised beds, because I figured the manure and organic granular fertilizer was enough. I didn't realize these things take time to break down and become available for plants. I planted my peppers/tomatoes in the raised bed too soon and they were stunted. I also used SFG method and cramped the tomatoes in the raised bed way too closely, resulting in some bacterial and fungal issues. So there was a lot of learning from Year 1 to Year 2 for me. My conclusion last year was that containers were better than the raised bed and my plan was to max out on containers this year. After some research and thanks to the helpful folks on this board, I was able to properly time my planting and water when needed. So far, I am having excellent growth and yields from both the raised beds and the containers. My plan is to move over exclusively to raised beds next year.

How large is the plastic grower's pot? When I do this, I just invert another plastic grower's/nursery pot inside the decorative container and rest the planted pot on top. I try to scale the size of the growing pot to fit pretty closely to the decorative pot diameter, so it looks like it is actually planted in the decorative one. But for long term plantings I tend to plant directly into the larger glazed pot - most of my trees are planted like this and they do get moved around......a lot :-)) It's a bit of an effort but very doable and I am getting to be a old thing!! In my climate there is little concern about heat or cold damage to anything grown in a container with a few minor exceptions. A lot depends on what you are growing but a zone 7 shouldn't pose many concerns. And a pot-in-pot planting will afford a greater degree of insulation than just direct container planting.

I think that what "look" you are going for will drive both the container and furniture choices. Right now you have a limited palette dominated by green, with texture creating the interest. If you want to continue that calm feel and the outward forcus toward the river, then any planters should continue the palette of green, white or gold (not sure what color the hostas have) with the plants and gray/black with the furniture and the pots themselves (if any) also in that range. If your goal is to add more energy to the scene with the perennial plantings providing the frame, then choose furniture items and pots that include other colors that really pop. I don't think I would add just a little color or pastels; I would want one of the extremes. For the second scenario, the pots would be needed, but for the first, more limited palette, it would depend on the furniture chosen, both style and amount. You don't want that arrangement to look cluttered or busy. I know that's you didn't ask about this, but I find the tall things by the river to be disruptive to the view. Can whatever function they serve be accomplished with something shorter or something mounted in the trees?