AUTUMN is a time of year when we naturally look towards our broadleaved trees to provide us with a rich tapestry of colour in the lowering light levels.

But there is so much more to the autumnal finale for gardeners who cling onto the light and vibrancy of the summer days and edge reluctantly towards winter, as I do.

While preparing a horticultural identification test for our new trainees (which is a list of 40 ornamental grasses from the garden and their complementary herbaceous companions), I was struck by just how glorious some of our later flowering plants are.

Rudbeckias, or cone flowers, are known for their late season show, but Rudbeckia fulgida var deamii is like a radioactive glow of yellow, tucked away behind the gorgeous Persian ironwood tree (Parrotia persica) on the Main Borders.

They are a fantastic genus of plants – part of the daisy family, heralding from the prairies of North America – and they positively radiate late summer sun.

When the petals finally fall, they provide not only beautiful winter skeletons, but also food for the finches who alight and pick the seeds out with their specially-adapted beaks.

There are some very tall rudbeckias should you want some late colour and height. R Herbstsonne is a delight, but this will wobble in the wind and is liable to collapse in the frosts. The shorter varieties are more robust, such as R deamii and R sullivantii, another glowing variety and, in my opinion, better visual value and lower maintenance.

Cut them all down in late spring as they like good drainage, but, apart from that, give them a sunny spot and they will glow well into November.

Excellent companion plants for rudbeckias are molinias. They are a genus of ornamental grasses with two distinct species – tall and short. There are a number of different varieties at Harlow Carr, and they all provide beautiful movement and texture to the borders.

The tall ones, such as Skyracer and Transparent, have 6ft tall delicate, airy flower spikes, which quiver in the slightest breeze.

They bring a depth and shimmer to the borders and turn butterscotch yellow when the temperatures drop, but do tend to collapse in late winter.

Harlow Carr has a small molinia called Overdam, whose spikes have a hint of mauve and look stunning against fading foliage.

Another gorgeous grass is Deschampsia cespitosa.

We have Goldtau, and the golden haze which envelopes the planting explains the name. All these grasses like well-drained soil, but will take buffeting from the wind and look so graceful and beautiful with many herbaceous companions.

Nestled on one of the island beds is another late splash of colour. I have found asters really disappointing to grow with the mildew problems, but Aster x frikartii Monch is a stunner.

It has the accolade of the Award of Garden Merit from the RHS, suffers no such problems, and flowers prolifically for at least four weeks, with no staking required.

The dainty blue-mauve petals with a yellow centre are a late nectar bar for the last butterflies of the season.

Energise yourself with some late colour in your garden and store that heat and light away for spring. Before you know it, the snowdrops and aconites will be heralding the start of another exciting growing season.

Harlow Carr Diary Dates

Throughout October 7:30pm-10pm

60th anniversary celebrity lectures Join celebrity gardeners sharing their knowledge and experiences at a series of anniversary lectures in the Bramall Learning Centre. Speakers include Matthew Wilson and Toby Buckland. Must be booked on 0845-612-1253. Tickets £35 (£30 for RHS members).

A Taste of Autumn October 23-31, 10am-3pm

The half term starts with a weekend dedicated to the autumn harvest with cookery demonstrations, walks, displays and advice from the Northern Fruit Group and the Mid-Yorkshire Fungus Group. Then, if you’re really brave, take part in one of the spooky Halloween monster trails. Beware – you never know what is lurking in the woods.

Diamond Anniversary Quest November 1-30, 10am-3pm

The diamond anniversary of the gardens calls for something a bit sparkly so visitors are invited to have a go at locating a real diamond in the garden. Follow the clues on the precious gem trail to help you on your way.

■ Events at RHS Garden Harlow Carr are free with the normal garden entrance fee, except where stated. For further information call 01423-565418.

RHS Garden Harlow Carr, Crag Lane, Beckwithshaw, Harrogate HG3 1QB. Open every day of the year, except Christmas Day, from 9.30am until 6pm (or 4pm Nov-Feb inclusive). Last entry one hour before closing. RHS Members free, adults £7, children (6-16) £2.50, under-sixes free.

Gardens: 01423-565418. Shop and Plant Centre: 01423-724666. Bettys Tea Rooms 01423-505604.

Sarah Bell

Floral Team Leader, Harlow Carr