For renters: to pot or not to pot
If your garden isn't yours, don't despair. You have two options: the first is pure altruism: plant what you like, and reckon that your successor will reap the benefits of what you sowed. The second is more selfish, but no less wise: plant whatever you want, but do it in pots. Then, when you move, your garden goes with you. We have done this successfully for almost four years, and when we go, so too do many of our much-loved pots and plants. And when people think of pots, they think of little pots spilling over with summer annuals.
But we have trees such as Ginkgo, hornbeam, beech, banana, Japanese maple, Magnolia and pine, as well as bamboos, herbs, and perennials such as Agapanthus and Crocosmia. All these plants thrive in containers, and some do better than they do in the ground, because you have absolute control of their soil.
There are only two things to bear in mind if you have plants in pots: you need to water them regularly (never rely on the rain, as it miraculously doesn't always get into the pots).
And make sure they don't go hungry: in other words, make sure that they are re-potted or fed from time to time. Finally, always chose as large a pot as possible - they need less watering, are more stable, and plants need less feeding or repotting if they have plenty of room in which to grow.