There are few plants that can’t be grown in pots, at least for a short time. The evidence is that we go to garden centres and buy plants in pots all year round. But plants in pots have limited root-run, need constant attention and care with watering and feeding and may get too big for their pots. Most will need moving into larger pots after a while. We also probably want plants in pots, which will probably be in conspicuous places in the garden, to look good for as long as possible. So there are some plants that I would not put in pots. These include rhubarb, which is just too hungry and needy, and peonies, which are really not happy in pots.
But, I hear you say, you can buy peonies in pots! Hoisted by my own petard! Well, actually, no. Peonies are grown in the ‘field’ and then lifted and potted for sale. The same is true of roses (except some miniatures and patio roses). They are budded in the field, grown and then dug up, the roots trimmed and sold in growth. Actually growing them in pots would cost too much.
So, back to the roses in pots. Roses will grow in pots but with some caveats. It is best to grow short or ‘patio’ roses rather than large cultivars. You must use pots with wide tops and straight sides so you can repot them, which will be needed every year or two years. This may be to move them into larger pots in the first few seasons and to root prune and refresh the soil in subsequent years. This involves removing the plant from the pot, when it is dormant, chopping off the lower third of the roots and replacing fresh compost in the base and scraping away and replacing some of the top compost.
And speaking of compost, you must use a soil-based compost such as John Innes No 3. Roses are heavy feeders and they will need liquid feeding while they are in growth too. And lots of water, of course.
Plants in pots are likely to be more stressed than plants in the ground so always choose a variety that is less prone to disease.
I was prompted to write this because of a recent question about planting two climbing roses in pots either side of a front door, trained up trellis. Climbing roses always pose a special problem because it is difficult to repot a climber if it is tied to a trellis! Most climbers are too vigorous and ‘needy’ to do well in pots for long but ‘patio climbers’ such as ‘Laura Ford’ are suitable. These tend to have slender, twiggy growth and to produce leaves and flowers from the base. Most climbing roses will be bare at the base unless very carefully trained, and that is not very desirable in a potted plant in a prominent position.