If you're thinking about tidying up your garden this autumn, it's time to grab your secateurs—but don't go overboard. Experts say that while some pruning is necessary, it's best to keep it light, with most of the heavier pruning saved for spring. This is especially important this year, as many plants have been affected by drought, and gardeners need to be careful about what they cut. "The easy rule is that anything stem-wise that's dead or dying can be cut out at any time," says Leigh Hunt, an RHS principal horticultural advisor. But for plants that are still alive, it's best to wait until spring to avoid damaging next year's growth. One area where light pruning is recommended is with perennials that have finished flowering earlier in the season. Plants like delphiniums, lupins, phlox, Geums, and nepeta can be cut back now, according to Nick Hamilton, who runs Barnsdale Gardens in Rutland. However, some plants are better left alone in autumn for their visual and ecological value. Plants like eryngium (sea holly), echinops (globe thistle), rudbeckia, and heleniums can look striking in the cooler months, especially with dew or frost. Grasses should also be left until later in the season, as they provide movement and interest in the garden. Additionally, leaving seedheads on plants like echinacea can provide food for birds, and hydrangeas should be left with their flowers to protect emerging shoots through winter. Lavender is another plant that requires careful pruning. A light trim is recommended, but avoid cutting too hard, especially if a harsh winter is expected. If the plant hasn't regrown after summer flowering, it can be left or lightly shaped. If it has flowered again, a light trim is acceptable, but avoid cutting into old wood. For spring-flowering shrubs like philadelphus, deutzia, and exochorda, a light tidy-up is possible if they have outgrown their space, but avoid heavy pruning to preserve next year's flowers. Autumn is also a good time to trim hedges, which will help them look neat through the winter and prevent regrowth until next spring. For conifer hedges like leylandii or western red cedar, pruning should be done by September at the latest to avoid brown patches. When pruning, use hedge trimmers or shears, but for plants with large leaves like laurel, secateurs might be better to avoid damaging the plant. Finally, as autumn comes to a close, give roses a light trim to prevent wind rock, and leave further pruning until spring.