Autumn: the best time to plant

Autumn is my favourite season in the garden, and not only for the colour. The soil still holds the warmth of summer while the rain has come back, which means anything planted now has months to settle its roots before it has to do any real work.

Why I plant in autumn

Trees, shrubs, hedging and perennials all establish better from an autumn planting than a spring one. They go into winter with their roots growing and come out the other side ready to put on top growth, and they need far less watering through their first summer.

From November the bare-root season opens, which is the most economical way to plant a new hedge or a run of young trees. Hornbeam and beech both do very well planted this way, and a bare-root hedge put in now will be knitting together by the following autumn.

Hold off on the big tidy-up

It’s tempting to cut everything to the ground in October. I’d hold back. Ornamental grasses and the seed heads of plants like sanguisorba and echinacea look wonderful catching low sunlight and the first frosts, and they give birds and insects food and shelter through the colder months. A border cut back hard in autumn can look bare for five months of the year.

Cut back anything that has collapsed or gone mushy, and leave the rest standing until late winter.

Bulbs for next spring

Daffodils and alliums go in during September and October, planted at roughly three times their own depth. I leave tulips until November, when the colder soil helps keep tulip fire at bay. Plant them in generous drifts rather than dotted rows and they’ll look far more natural come April.

Giving the lawn some attention

Early autumn is the right time to repair a tired lawn. Scarify to pull out thatch and moss, spike compacted areas with a fork to let air and water in, overseed the thin patches and finish with a light top-dressing. Keep fallen leaves raked off so the grass underneath doesn’t yellow, and bag them up to rot down. Leaf mould is one of the best mulches you can make, and it costs nothing.

Looking at the bigger picture

Autumn is also when the structure of a garden shows its strengths and its gaps. As the perennials fade you can see clearly which areas rely on summer flowers alone and which hold their shape. If you find yourself wishing for more evergreen structure or somewhere to sit and catch the last of the sun, now is the time to plan it.

Winter is a good season for building, so a design agreed in autumn can be in the ground and ready for spring.

Rob