Here are a few plants left in the ground overwinter. Sown in April 2006, these deliciously and randomly coloured brassicas eventually grew to about 2' tall, and as much across. Their fat squeaky leaves top off stems or ribs of the most dazzling colours, white, yellows, reds, ochres, deepest burgundy that bleeds onto your hands and Felco blades. After a good rinse, I chop the stems and stir fry quickly, then throw in the leaves to wilt, then drop them all into a dish covered by a white cheesy sauce, then into the oven to brown. Yummy.
These beauties are "come and cut again" plants, that is, you keep cutting the stems, a few at a time from each plant just enough for each meal. The plant responds by producing more leaves, and over the months you get a succession of fresh and scrunchy leaves. Essentially this is the idea behind rejuvenation pruning, where we take an old or neglected plant and cut out a third of it's growth each year for three years. This minimises the pruning shock to the plant, and ensures that we have at most a three year old plant flowering at its maximum. Some plants are deliberately hard pruned in spring, right to the ground. This rather alarming procedure prompts the plant to produce entirely juvenile growth over the course of a single year or season. This is especially useful if we want to keep vigorous plants within garden boundaries, buddleias for example, or where we want the colourful juvenile / one-year old stems for winter colour, dogwoods.
I've kept last year's Swiss Chard for an entirely different reason. This year the plants will rapidly go to seed, producing huge feathery fronds topped with little bunching flower heads, that give a delightful, airy feel to this work horse of a brassica. It's almost as if left to overwinter into its old age, Swiss Chard finally blossoms into a thing of ethereal beauty, and becomes a magnificent dramatic centrepiece for the vegetable garden. That I know this comes only from my failure to lift all the tired Swiss Chard a few seasons ago, as I was too busy and too tired myself... Sometimes our failures aren't failures, only time imposed upon us to allow something else of greater beauty to come into being.