As my wife has had MS for years now, even getting into our small garden requires a considerable effort. So although the borders are densely planted, we have about fifteen roses in ceramic pots on the patio. These sit on "pot movers" so I can easily re-arange them in order that she can see the best in their turn from her chair in the lounge
I created a small circular bed in the centre of the garden. At the moment there's a sambucus in a big container in the centre, surrounded by three azaleas which will eventually hide the container. When they flower, I can change it for a Conference pear, or a Stellar cherry, which are in similar tubs presently on the small patio behind the shed.
I bought these cheap wooden containers quite some time ago. They just happened to fit nicely either side of our tea-house steps. I painted them to match.They are supposed to have solid wooden bottoms. But that would lead to rot. So I removed them and replaced them with two 2" wooden rails along the length of each. Three ten inch plastic pots fit in nicely. In the summer they sit on plastic saucers. In the winter I upturn the saucers so water drains away. I used to swop lilies for dahlias in them during the year, but it became a bit of a bother, so now they have hebes that have flowers for a considerable number of months.
These are our "tree azaleas" they too are in ceramic pots and sit on round paving stones set in the lawn. If it's likely that there may be some very cold weather in winter they can be quickly moved into the shed.