So I've been gardening for about 15 years now...mainly as a container gardener, and a bit of gardening done in a 'real yard with dirt'. But most of my experience is with containers.
While I know containers have their own unique needs (more frequent watering, and extra protection for the plant/roots during the colder months), aside from that, I'd always been of the understanding that most anything that can grow in a traditional dirt yard can also be grown in a container. But that you may need to do a bit of pruning now and then...of the visible plant...of the root ball...and providing extra soil ammendments...potting-up as needed....so that the plant is happy in its container.
And indeed, I've successfully grown a number of perennials in pots...blueberry shrubs... hydrangea... Japanese maple, etc.
This past fall I bought a bareroot Rosa Setigera. Come this past Spring, I noticed that while other gardeners in the area (with DIRT yards) ...I noticed that all their rose bushes were in full bloom, my Rosa Setigera barely had any leaf growth, never mind flower buds or flowers. The response I received about this was for the most part that 'this is NOT a plant that can grow in a pot'. (I took that comment to imply that THAT was why I was not seeing any new growth...that my putting it in a pot had already ruined any chances for survival/new growth...) However, a few other people explained to me that this type of rose blooms later in the year than traditional rose shrubs, and that maybe I just needed to wait a bit more. That said however, they also told me it may take a few years for me to see actual FLOWERING.
Sure enough, about a month or two after other traditional rose shrubs around me had flowered, my Rosa Setigera suddenly TOOK OFF like a plant in the tropics. While the plant is in a large pot (maybe 18" in diameter, and 16" high) and has a trellis to support the bulk of the growth.... the plant is already starting to 'take over the pot'.
Perhaps THIS is really what folks were getting at previously when they said this plant is NOT intended for pots.....not so much that this plant would never be off to a good start in a pot, but that.... it is way too prolific a grower to be able to be contained or happy in a pot, for very long?
I'd really hate to 'give up' and admit defeat on this plant but.... does anyone know if there are any 'tricks' to my having this thrive in a large planter? ...say if I were to constantly cut back the growth and/or the root ball? Or would that just be an endless battle/chore?
I'd hate for the plant to die and all, because it's so rapidly outgrowing the pot. (I'm also now seeing evidence of what appears to be 'mildew' on some of the leaves... see photos....). Should I just give up on it now, and gift the plant to someone with a real DIRT yard, and while the plant still has a chance to survive?