Pretty in pink

If you look around some gardens you may already see bulbs in flower now, such as crocus speciosus, banaticus and colchicum or autumn crocus. Unlike springflowering bulbs, these autumn dazzlers are planted during the summer. (A good representation of these can be viewed at Harlow Carr, near Harrogate, in either the new alpine display house or in the grounds of the garden).

Dry, sunny or semi-shaded sites can prove difficult, but the colchicum – commonly known as the autumn crocus – will thrive. It is a hardy perennial bulb that lies dormant for most of the season. Come late August, it starts to emerge, flowers first and, depending upon the species, will still be in flower in November.

The colour of the flowers can range from pink to magenta.

Some colchicum species will also grow well in dry woodland margins, where they will pick up the rays of the autumn sunshine and freshen up the dry barren soil at the base of many trees. They associate well with cyclamen hederifolium and coum.

In the wild, colchicums originate from as far as Western China, Northern India, Central Asia, North Africa and, a little closer to home, the alpine meadows and hills in Northern Greece and Turkey. In fact, a visit to Greece now, in particular around some parts of the Peloponnese, will provide great drifts of pink and magenta along the hillsides through what, only a few weeks ago, was a vast barren land.

Colchicums should be planted in late summer while they are still dormant. They will benefit if the soil is well-drained and fertile and retains some moisture deep down. On the heavy clay soils at Harlow Carr we incorporate a little grit or river sand into the soil medium when planting, otherwise the bulb will rot. It is important to remember when planting colchicums that you should always use gloves as they can be an irritant to the skin. All parts of the plant are toxic if eaten.

One of the earliest species of colchicums to flower is C. agrippinum. It produces deep pink to purple flowers, grows to a height of three to four inches and is more ideally suited to being planted in an alpine trough. Another colchicum is C. autumnale or meadow saffron, one of the more vigorous colchicums, which produces a light pink flower to a height of four to six inches. The flowers are followed by long, dark green, strap-like leaves that can reach a height of five to 14ins.

Colchicum autumnale is a little more robust and will tolerate sites at the base of trees or shrubs or naturalised in turf. Colchicum speciosum is another robust species, native to the mountain steps and alpine meadows of Northern Greece and Turkey. The flower colour ranges from rose pink to lavender.

The more unusual species C. waterlily can still be found in flower at Harlow Carr at this time of the year. It produces light pink, double flowers that benefit from some sort of support, and can be planted in between low-growing shrubs. A relatively new addition, colchicum cupanii, can be seen now in the new alpine display house at Harlow Carr. It only reaches a height of 10cm, and due to its delicate nature, is more suitable for alpine houses.

Colchicums are generally trouble-free and are only occasionally affected by Bortrytis and slugs. They give good value for money and will multiply for many years to come.

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. Speakers include: Jekka McVicar, Joe Swift, Cleve West and James Alexander-Sinclair, Andrew McIndoe, Matthew Wilson and Toby Buckland.

Booking essential on 0845-612-1253. Tickets £35 (£30 for RHS Members).

A taste of autumn October 23 to 31; 10am to 3pm

Cookery demonstrations, walks, displays and advice – everything you need to know about enjoying seasonal fruit and vegetables. Plus spooky Halloween monster trails.

Diamond anniversary quest November 1 to 30, 10am to 3pm

To celebrate the diamond anniversary of the gardens, visitors are invited to follow the clues to locate a real diamond.

For further information, call 01423-565418.

For more information on things to do in the garden in October, visit rhs.org.uk

❦ RHS Garden Harlow Carr, Crag Lane, Beckwithshaw, Harrogate HG3 1QB. Open daily from 9.30am until 6pm.

RHS Members free, adults £7, children (six to 16) £2.50, under-sixes free. Gardens: 01423-565418; shop and plant centre: 01423-724666; Bettys tea rooms 01423-505604.

To do this week...

❦ Place house plants where they will be warm, not exposed to direct heat or draughts

❦ Put a net over your pond to catch falling leaves and remove them regularly

❦ Sort out your containers and pots, discard annuals to the compost heap and save tender perennials in a conservatory or greenhouse

❦ Plant deciduous trees and shrubs when conditions are suitable, ensuring they are firmly staked and tied.