Garden expert Jo McGarry has warned that cutting back hydrangeas and several other plants in September can cause problems, urging gardeners to hold off on a full clear-out as autumn approaches.
Why September is not the time for a garden tidy-up
September is a crucial month for preparing the garden for autumn, but Jo McGarry, luxury garden design expert at Caragh Nurseries, said it is not the time to embark on a full clear-out. Leaving particular stems, seed heads and faded flowers in place can help safeguard plants through winter, add structure to the garden and provide food and shelter for wildlife.
“September is when a lot of people start wanting to tidy everything up, but I would definitely hold back on some plants,” said Jo. “A garden does not need to look completely bare going into autumn. Leaving certain plants standing can actually make it look more interesting, as well as giving wildlife somewhere to shelter.”
Five plants to leave alone this September
Hydrangeas are among the top plants to leave well alone, particularly mophead and lacecap varieties. Once the blooms begin to fade, there is no need to rush to cut them back.
“Those faded hydrangea flowers can look really lovely as they dry out and change colour,” said Jo. “They can add a bit of interest to the garden through autumn and winter, so I would leave them where they are and tidy them up when spring comes around.”
Ornamental grasses may appear untamed by summer’s end, but they do not require immediate trimming. “Grasses can look really good through the colder months,” said Jo. “They give the garden some shape when a lot of other plants have died back, and they look lovely when they catch the light or get a bit of frost on them. I would leave them standing and enjoy them through winter rather than cutting them back too early.”
Echinacea heads, though faded, should also be left undisturbed. “Echinacea can look really nice even once the flowers have gone,” said Jo. “The seed heads add a bit of shape to the garden and can provide food for birds, so I would leave them standing rather than rushing to cut them back.”
Sedum is another plant that does not need cutting back as soon as summer concludes. “Sedum can actually look really nice as it dries out,” said Jo. “The flowers change colour and the seed heads give the garden a bit of interest through the colder months. I would much rather leave it there than cut everything right back.”
Lavender is a variety where it is preferable not to become overzealous with the secateurs in September. “You can give lavender a little tidy, but I would avoid giving it a really hard cut at this time of year,” said Jo. “Once it starts getting really woody, cutting too far back can cause problems. A quick trim is fine, but I would leave any bigger pruning job until the right time.”
