Fool Proof Guide To Autumn Pruning

There’s a lot more to autumn gardening than simply chopping everything in sight. Here’s how to be prudent with your pruning for the best results, says Graham Rice

- Graham Rice

Never mind spring cleaning, in the garden there’s nothing like a good autumn tidy up. The urge to rake up leaves, chop back shrubs, prune perennials and shove it all in the compost or garden waste collection bin can be irresistible at this time of year. But before you sharpen the secateurs be aware that not all plants will benefit from being given the chop.

Exhausted and frosted annuals can certainly go on the compost – there’s no sense leaving their bedraggled foliage to detract from the chrysanthemums, perennial anemones and autumn bulbs at their peak. With perennials, however, it varies: some can be cut back now; others are better left alone until spring.

To chop or not to chop may be the question, but there simply is no definitive answer. It all depends on the plant. Some perennials – the likes of campanulas, phlox, astrantias and alstroemerias – are best cut off at soil level; the same applies to fennel, which will otherwise repay you with a forest of irritating seedlings.

With others, there are definite benefits to holding fire. By not cutting back the statuesque Phlomis russeliana, achilleas, eryngiums, perennial astilbes, sedums, alliums and many ornamental grasses, we can enjoy their structure against a winter sky – the sight of their stems silvered with frost adds a whole new level of interest to the garden.

The third way

There’s also another option: cutting back, but only by half or a third. This is the ideal approach for the likes of penstemons and agastaches. If left alone they will rock in winter winds, the roots will be loosened and their chances of survival greatly reduced.