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Autumn in the Rock Garden

December 3, 2021
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Extending the season

It is true that spring and early summer provide us with most of the chief joys of the alpine garden. And we all impatiently await the appearance of our favourites as the days lengthen. However, many of the loveliest flowers suitable for the rock garden save their show for late summer and autumn. And there are also the plants that we grow primarily for their structural and foliage contributions. These often come into their own as the days shorten and the sheer floral extravaganza of spring and summer subsides. Then there is more time to observe and enjoy plants that might not receive our full attention in the peak season.

I shall show you a few of these, including some bulbs, dwarf shrubs and other miscellaneous beauties. All are easy to grow in any garden provided the site is reasonably sunny, and the soil is free draining.

Colchicum umbrosum


Given their ease of cultivation and their striking impact in the autumn garden, it is surprising that few keen gardeners seem to realise the potential of colchicums. I think this is partly because of confusion over names. A bag of colchicum bulbs in a garden centre might be labelled (say) Colchicum autumnale (correct), Autumn Crocus, Meadow Saffron, or Naked Ladies. Autumn crocus is confusing because while superficially similar, colchicums and crocuses are only distantly related. Also, this plant is not the source of saffron (colchicums are actually poisonous). Saffron is derived from a true crocus, (Crocus sativus). The lovely old English name Naked ladies derives from the appearance of the flowers directly from the earth before there is any sign of leaves.

Do not let this confusion over namingĀ  deter you from obtaining and planting colchicums as they will provide an annual source of autumnal delight. But if you want to unravel the mysteries of a genus of more than 100 species and many cultivated varieties, why not seek out the comprehensive new AGS monograph on the subject.

Colchicum byzantinum


Most of us think of crocuses wide open in the late winter sunshine as being one of the first and most joyful indications that spring is on its way. While I would not wish in any way to diminish their role as harbingers of better days, I want to remind (or inform) you that many crocus species flower in autumn rather than spring. And their presence in that relatively bleak period in the rock garden is almost equally appealing.

Autumn-flowering Crocus niveus

Crocus niveus, Gytheio, Peloponnese.


To most newcomers to alpine and rock gardening cyclamen are tender houseplants one can buy in garden centres every autumn and winter. Few realise that there is a wide range of hardy species, many of which will be perfectly happy in the open garden. Others are best grown in containers, with or without protection depending on the climate in your area.

Cyclamen mirabile exhibited by Don Peace

Other autumn bulbs

There are quite a few other bulbous plants suited for cultivation in the rock garden that flower in autumn.

Sternbergia sicula

Autumn gentians

Even keen alpine gardeners grow these gorgeous plants far too seldom. This is partly because, coming as most of them do from the periodically cool, wet mountains of Asia, they are not that easy to cultivate in the dry conditions of the south and east of the United Kingdom.

There is no excuse for not trying them if you garden in the cooler and damper north and west. Their chief requirement is full sun (they are mostly alpine meadow plants) and organically enriched, neutral to acidic soil. Their worst enemy is intense heat associated with prolonged drought. If you can master the conditions and obtain good stock from a reliable specialist nursery you should succeed where others fail.

Autumn alpine flowers

Spring is without question the peak period of interest in the rock garden. But autumn has many plants that would hold their own if they flowered at that joyous season. In the article below I highlight a few of my favourites. As well as ‘specialist’ autumn flowerers, I include some that bloom almost continually from spring to the first severe frosts. I recommend you attend an AGS autumn show and make a choice from the nurserymen’s wonderful displays. Remember, however, that many of the plants will have been grown with some protection so may not be fully frost hardened when purchased. I advise keeping them in a cold frame or unheated glasshouse through the winter and planting in early spring.

autumn flowering Silene schafta at Aberconwy Sept 2021

Silene schafta

Silver foliage

Colour of any sort is welcome in the rock garden in autumn and winter. But few plants can be relied upon to produce a good show of flowers at this time. So we need to look wider and think of how foliage form, colour and texture can help fill the gap. Evergreen silver-leaved shrubs provide an ideal solution in winter. Additionally, some are also good in flower at other times of the year.

Berried shrubs

Berries and autumn are synonymous. What is more evocative of crisp, frosty mornings in the garden than a crab apple or rowan tree bedecked with colourful fruit. There is a good choice available of dwarf berried shrubs suited for the rock garden. These include rowans only a few inches high. Also consider a range of ericaceous shrubs with berries in colours from white through pink to red and black.

autumn berries shrubs on the rock garden

Gaultheria 'The Pearl'