Clearing and pruning the garden in autumn: do's and dont's

Some plants should not be pruned in autumn because their branches are too delicate to survive the winter. Just leave the spent flowers as a layer of insulation and protection against inclement conditions such as frost and wind. Hydrangeas, for example, should only be pruned in early spring, just after winter.

Blooming flowers with seed pods are an interesting addition to the winter diet of many animals. Examples are: Allium (ornamental onion), Echinops (ball thistle) or Eryngium (cross thistle), Hylotelephium (celestial spurge), Nigella (damsel-in-the-green), Phlomis (fireweed), Rudbeckia (sunflower) and Echinacea (red sunflower). Prune them only after winter.

Not everyone is into spent shrubs or brown branches, but ornamental grasses are very beautiful when frost covers them with ice crystals or when winter light plays with the spikes. Ornamental grasses are also pruned in early spring, just after winter.

Shrubs that have grown very full or dense during the past season, such as roses or jasmine, can be thinned out with secateurs. You will remove a few branches here and there that grow too close together, without cutting the entire bush! This ensures more air circulation in the damp winter months and thus less chance of fungi and diseases. In addition, you make the shrub a little less heavy, so it is less impacted by strong winds or stormy weather. Sometimes pruning is also necessary, it turns out.

Many small fruits can be pruned now, such as black or red currants, summer raspberries, gooseberries and blackberries. For larger fruit trees, such as apples and pears, it is far too early to prune now. Their sap flows have not yet stopped and they are susceptible to disease if you prune them now. Waiting until winter makes its appearance is the message. For stone fruits, the time to prune has already passed. You can prune them just after harvest, until mid-September. 

Lavender may be pruned after flowering, in early autumn (September). Remove only the spent flowers now; the major (shape) pruning is for March. Rosemary, too, you may tidy up before winter, but the major pruning is also for spring.

Most hedges are pruned the last time in September, leaving plenty of time for the pruning wounds to recover from the first frost. Yew hedges tolerate a slightly later trimming and you can also prune in October. 

Some spent perennials do not form sturdy stems with seed pods, but become a kind of brown mush in winter. Persicaria (knotweed), for example, or Alchemilla mollis (lady's mantle) are safe to clear out in the fall.

'Dirty corners' may seem not done in the garden, but they are vital for the overwintering of many creatures. Hedgehogs seek shelter under tasks and leaves, but toads also like to hibernate in such places. Insects crawl away in spent flower heads or under leaves and stones. So don't go crazy cleaning up and pruning everything, but leave some garden waste here and there for the coming winter.

Make an insect wedge with branches, trimmings and leaves. You then put 3 to 4 medium-sized branches in the ground that you can now prune. Connect them tipi-wise and tie them together with a rope at the top. If necessary, prune the branches to an even height. Fill the inside of the wigwam with trimmings, small twigs and plant scraps or leaves. Anything you are pruning together now is good to use. You can even cut the stems of sunflowers shorter to incorporate them; little animals like to hide in them. If necessary, tie some more rope around the wigwam or teepee so that not everything can blow away, and leave the rest to Mother Nature. Lots of insects will spend the winter in it. Ideal to make with kids. Prune and tinker away.

The annuals from last season can be safely cleaned up and thrown on the compost pile. Sunflower heads can be left to dry on the windowsill or garden table to use as bird or chicken feed. Some varieties, such as Zinnia or Cosmos, do continue blooming until frost. After that, they may be gone.

You can keep cutting the grass until when the temperature dips below 10°C. From then on, the grass stops growing and goes into hibernation. By the way, don't mow the grass at the shortest setting, but make sure the grass blades are long enough to go strong into winter. 

You may also clean up most summer crops from the vegetable garden after harvest. Consider all frost-prone plants such as beans, tomatoes, zucchini, cucumbers, eggplants and peppers. Once the last of the vegetables have been harvested, the plants can be put on the compost pile.