Alpines for autumn

Alpines are classic spring flowers... or are they? Expert plantsman Graham Rice begs to differ

Whether in the Alps and the Pyrenees, or in our rock gardens and raised beds at home, it’s often thought that alpines sparkle most brightly in the spring. Well, yes… but there are some lovely alpines that wait until autumn to give their best and bring valuable colour to parts of the garden that in September and October would otherwise look rather dull.
Gentiana sino-ornataThe Chinese autumn flowering gentian must be top of the list. Gentiana sino-ornata holds up its flowers in the spectacular vivid blue that we expect from gentians. Its bold trumpet shaped flowers are up to 6cm (¼in) long, and prettily striped white inside, and stand up from a low carpet of foliage.

Gentiana sino-ornata 'Purity'It needs moist but well-drained soil, which must be lime free, and a position in partial shade usually suits it well. There are also several white forms (such as 'Purity', see right) and ‘Kingfisher’ which is neater and shorter than the species, with narrower leaves.

Find out more about growing gentians.

Daisies and knotweeds - but not as you know them

Two species of late-flowering persicarias are amongst the most reliable of autumn alpines. Both are sun-loving carpeters, with spikes of flowers standing up from their mats of evergreen foliage. They’re ideal sprawling over sunny rocks.

Persicaria affinis 'Hartswood'Persicaria affinis is the larger and more varied of the two, reaching 25cm (10in) in flower and spreading to 60cm (2ft) or more; its dark elliptical leaves develop lovely russet colouring, often as the flowers are at their peak. The pale pink flower spikes fade to rich rosy red over many weeks, so that flowers in a variety of harmonious shades are open together. ‘Donald Lowndes’ is a little shorter and neater than other forms at 20cm (8in).
It has a smaller, neater red-stemmed relation, P. vaccinifolium, whose much shorter, dark green leaves turn red in the autumn and whose pale pink flowers are carried on longer and more slender spikes. It does, however, like the gentian, prefer a lime free soil.
Chrysanthemum yezoenseWhen I first saw Chrysanthemum yezoense flowering in November on the rock garden at Kew, it was clear that this is a plant that’s rather special. Its white daisies face upward on slightly reddish 20cm (8in) stems above neat fleshy leaves, and it spreads slowly at the root. Tough and adaptable, any reasonably free-draining soil suits it and it loves the sun.
Finally, another white daisy, but one that makes a twiggy little shrublet covered in bright silver, finely-divided foliage. Rhodanthemum hosmariense is a plant for a sheltered sunny pocket of well-drained soil and preferably backed by a large rock or stone or wall. It’s borderline hardy in much of the country, but in a good site will reward you with white daisies in autumn and sporadically through the winter.
There may be far fewer autumn-flowering alpines than spring-flowering types, but we should be sure to grow what few there are. Combine them with dwarf autumn-flowering bulbs, and you have a rather special autumn display.

Alpine open day

Alpine Open Day  – 1 October

Join experts and enthusiasts from the world of alpine and rock garden plants at this joint RHS, Alpine Garden Society (AGS) and Scottish Rock Garden Club (SRGC) open day at RHS Garden Wisley.

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