Clumber Gardener: How to keep the summer going a little bit longer

Chris Margrave, head gardener at Clumber Park
Chris Margrave, head gardener at Clumber Park

September is a month of great change in the garden.

Early September still has a summery feel, but, unless we get an Indian summer, the end of the month can appear distinctly autumnal.

We can hang on to summer by keeping the garden tidy, feeding and watering plants and removing faded flowers.

Summer bedding and container and hanging basket displays can be kept looking good by regularly removing faded flowers, a process known as dead-heading.

And keep feeding with a liquid fertiliser, the feeds for tomatoes, which have a high level of potassium, are ideal.

If an early frost is forecast, it’s worth covering container plants with horticultural fleece overnight to prevent damage.

Hardy and tender perennials also respond to dead-heading and dahlias are the classic example.

We grow lots of varieties in the walled kitchen garden at Clumber and they all have faded blooms removed.

The smaller flowered forms such as the pompon Snowflake and the single flowered Romeo and Moonfire respond best.

Not quite dead heading, but the same principle, if you are growing French and runner beans, keep harvesting the pods.

This will encourage plants to continue producing pods.

Clear up and, ideally compost, fallen leaves, particularly those which have fallen onto lawns.

As well as keeping the garden tidy, this will help the turf to stay healthy.

An autumn lawn feed, high in potassium and low in nitrogen, can also be applied and the cutting height of your mower can be raised to around three centimetres.

It pays to take stock regularly in your garden to see if there are times of the year when the displays could use a lift.

For September the choice includes flowers, foliage and fruit.

Perennial September flowers include Michaelmas daisies, late flowering geraniums , heleniums and sunflowers, sedums and crocosmias.

For the front of the border, or in a rock garden, Persicaria vacciniifolia, which combines pink flowers with bright red foliage and the autumn gentian, Gentiana sino-ornata, which produces gorgeous blue flowers would be my top two.

September is a good time for planting as the soil is warm and usually moist.

Container-grown plants will have a few weeks to continue growing and to start getting established before the onset of cooler weather.

This is one of the peak cropping months in the kitchen garden and there are lots of vegetables to harvest, from tomatoes and peppers under glass to salads, French and runner beans and main crop of potatoes outside.

Cover perpetual fruiting strawberries, such as Mara des Bois, Aromel and Flamenco, with cloches to help developing fruits ripen and to protect them from blackbirds.

Cover garden ponds with netting before autumn leaf fall starts.

Order or buy spring flowering bulbs.

Daffodils and narcissi benefit from September plantings, whilst tulips and hyacinths are best planted in October.