Hardy Cyclamen for All Seasons

Cyclamen Species and their Origins

Cyclamen is a small, very distinct genus. There are 20-23 species depending on which expert you are talking to. The various species are native to parts of Europe and western Asia, with two outliers in North Africa. Cyclamen africanum is restricted to Algeria and Tunisia, while Cyclamen somalense occurs in a small area in Somalia. All the species except Cyclamen somalense are well established in cultivation. There are few natural hybrids because cyclamen species do not generally cross breed. Even in cultivation, where species that would never meet in the wild grow together, hybrids very rarely occur.

The genus Cyclamen is part of the vast primula family, Primulaceae. This contains not only primroses and cowslips, but also other notable alpine plants as ‘shooting stars’ (Dodecatheon) and ‘snowbells’ (Soldanella).

Everyone recognises a cyclamen flower, perhaps mainly due to a familiarity with the widely available houseplant. These are cultivated forms of the non-hardy species, C. persicum. Some of the others that I shall touch on are not reliably frost hardy. To succeed with those, unless you live in a very mild locality, you may need to grow them in a glasshouse or cold frame.

Hardy Cyclamen Species

Of the species that most British gardeners can grow without protection, five form the backbone of the collection. These are, alphabetically, Cyclamen cilicium, C. coum, C. hederifolium, C. libanoticum and C. repandum.

Half-Hardy species

Gardeners in warmer spots may well succeed outside with Cyclamen africanum, C. balearicum, C. mirabile and C. pseudibericum.

Tender Cyclamen

I shall not say any more about the few less hardy species (Cyclamen creticum, C. cyprium, C. graecum, C. maritimum, C. persicum, C. rohlfsianum and C. somalense). They are all highly desirable plants for protected cultivation, in an alpine house.

The Cyclamen Plant

The Tuber

All cyclamen grow from single, long-lived perennial tubers (swollen underground stems). These enable them to survive periods of desiccation. After flower and seed production, the leaves die back to the tuber, along with most of the roots. It is in this dormant state that gardeners can often buy cyclamen in garden centres.

Tubers vary in size, shape and root production from species to species. This provides a valuable guide to identification in older plants. The largest tubers, Cyclamen hederifolium and Cyclamen africanum, can exceed 20cm diameter and may be well over 30 years old. The smallest, Cyclamen cilicium and Cyclamen cyprium, are rarely more than 2.5cm across. At least in my experience, the latter do not live as long.

Conservation concerns

Despite internationally accepted laws prohibiting their collection in the wild, many collected cyclamen tubers still reach the horticultural trade.

In the case of the rarer species, or those with narrow native ranges, this may threaten their long term survival. To avoid inadvertently buying these imported tubers, look to purchase young plants in growth and sold as ‘raised in cultivation’. Or, if in doubt, enquire of the seller the origin of his or her plants. Avoid large dormant tubers, especially if they are damaged or particularly desiccated, as they have probably been collected.

The Roots

Some cyclamen species produce roots from the bottom of the tuber, some from the top or sides only, while in others, they are more generally distributed. This characteristic may be used as an aid to identification. Root growth generally begins at or shortly before the production of new leaves and/or flowers.

The Leaves

Cyclamen leaves are of less than annual duration, in some species lasting for many months, in others much less. They arise from the top surface of the tuber, in some cases chiefly from a short ‘trunk’, in others from across the surface.

While leaves of most species are similar in general appearance (shape, size), there the similarity ends. For seeking out foliar variations is one of the joys of cyclamen growing. Some species are much more variable in this respect than others. See below a selection of various leaf forms of different species.

The Flower

There is little variation in the shape and size of the flowers of species cyclamen. They are small compared with the large, blowsy flowers of cyclamen grown as houseplants, but in proportion to the foliage. With very few exceptions, and then only in specially selected forms with upright-facing flowers, they are pendent. Tiny shuttlecocks come immediately to mind. In some cases the petals are straight, in others curled producing a propeller shaped flower.

Flower colour varies from deep reddish pink, through all shades of mid and pale pink to white. Albinos have been sought after and cultivated for many decades,. As a result albinos are more common in cultivation than in wild populations.

In some cases the outer surface of the petal is streaked with darker pigment, often producing striking results. The stamens (male parts of the flower) form a tube around a single style (female part). The latter, extends to or beyond the mouth of the flower, depending on species.

Pollination and Seed Capsule Development

Cyclamen flowers rely chiefly on insects for their pollination. If you are growing them in pots under cover where few insects are likely to find them, and wish to get seed, try pollinating them artificially.

This is simplicity itself. Get a small, pointed, fine bristled brush of the type used by children to fill in painting books. Insert it into the flowers and twist to dislodge some pollen from the anther cone. Then transfer it onto the stigma (tip of the style) of the plant destined to be the seed parent. Even if you don’t go to this trouble you are likely to get some seed set, as cyclamen are mostly self-fertile.

Successful pollination in nearly all species is indicated by shrivelling of the flower and coiling of the flower stem like a watch spring. This draws the incipient seed pods into the heart of the plant. Whatever time of year the species flowers, the seed capsules generally mature in the following summer. They are quite large in some species, generally globose, and with a thin skin.

Cyclamen Seeds

The seeds have a sticky, sugary coating, which dries as the capsules mature. This is indicated by them splitting at the apex to reveal the seeds within. Their sugary coating makes the seeds irresistible to ants and other invertebrates, which carry them off, thus aiding dispersal. This explains why you often find cyclamen seedlings far removed from their parents in the garden.

For that reason, if you wish to harvest the seed it is wise to collect the pods as soon as ripe. Then sow the seeds immediately. If this is not possible, for example when donating seed to a seed exchange, seed will remain viable for months if not years. Just store it dry in a cool place or refrigerator. However, this may induce a deep state of dormancy that is not easily reversed.

Propagation

Vegetative Propagation

The only way to propagate cyclamen reliably is from seed, but first a word about vegetative propagation. It is possible to cut tubers into sections, each with some roots and a portion of the growing points. The best time for this seems to be soon after the leaves and flowers shrivel. The method is rarely attempted and guidance is very limited. One can also propagate cyclamen by leaf cuttings, but this is fairly difficult.

If propagating by division, it is best to soak the sections in a solution of fungicide, diluted as per manufacturer instructions. Then pot the sections individually in freely draining compost. Maintain them out of direct sunlight in a shaded frame or glasshouse, keeping the compost just moist; overwatering is fatal.

The chances of success are small, fungal and bacterial decay often proving fatal despite precautions having been taken. Hence this method is only generally attempted to rescue a valued plant whose tuber has been damaged or is succumbing to disease.

Propagation by seed

Raising cyclamen from seed is easy and very satisfying. Sow seeds as fresh as possible. Old stored seed may produce little or no germination. But soaking stored seed overnight in water, with a little dishwashing fluid added, may markedly improve water uptake and germination. Sow ripe seeds in the second half of August at the latest. These will readily germinate by the end of September. If sowing is delayed, germination may not occur until the following autumn.

Our Seed Exchange has a good number of species and cultivars on offer every year.

The exact composition of the seed compost is unimportant, as long as it is moisture retentive but freely drained. I sow the seed on the surface of firmed compost in 10cm diameter plastic pots, covering the seeds with 1cm of grit. To avoid a mix up later, make sure to label the pots carefully, as most cyclamen seedlings look alike! Water the pots thoroughly and put them in a shady place without protection (except for tender species which need protection).

In the spring, keep an eye open for the tiny emerging seedlings, as they are easy prey for marauding slugs and snails.

growing on

Most seedlings only produce a single, small leaf and a tiny tuber in their first growing season. They are really too small to risk pricking them out. Keep them growing as long as possible by careful attention to watering. Feed occasionally with a weak general fertiliser. It is easy to forget about them when they die down, but ensure that the compost is kept just moist.

I generally prick out the seedlings individually in their second growing season. The compost I use is the same as for seed sowing, typically three parts John Innes no. 2, two parts coarse grit sand, one part well rotted leafmould.

Perlite in place of the grit sand is equally good, and leafmould may be replaced by composted forest bark, but that is not as good. If you have more seedlings than you require, select those with especially good foliage. Or even wait until they flower for their first time, generally in year 3 or 4.

If you have room, keep the rejects as cyclamen are always an appreciated gift for fellow gardeners. Water and feed to bring the seedlings along without check, easing off as the leaves begin to die down.

Don’t be anxious to pot on the seedlings too soon, cyclamen do best with a restricted root-run. It is better to keep them underpotted. But it is a good idea to scrape away some of the old compost from around the dormant tuber, replacing with fresh. A half-strength solution of a liquid general fertiliser may be applied from time to time while the plants are in growth.

planting out

Seedlings from pots may be planted out at any time of year, but I have found that just as the tuber starts into growth is best. If the soil is very heavy try to lighten it with additions of leafmould or composted forest bark, and perhaps some gritty sand.

Established cyclamen tubers are generally tough and resilient, and not often damaged by drought. But when newly planted water regularly until they are established.

The Species in their Seasons

It seems logical to begin the cyclamen seasons in January. This is good, because January into February are the months of peak flowering of one of the best hardy species, Cyclamen coum.

Cyclamen coum

In most years in the UK, this diminutive elf produces its first leaves and flowers in December. A reasonable show is usually expected in time for Christmas. It flourishes best in part shade, especially in hotter climates. Like the better known C. hederifolium, it grows well in those difficult places beneath the canopies and among the roots of large deciduous trees. It is a very hardy species, its leaves and flowers are generally undamaged by snow and ice.

Also, like C. hederifolium it is a very variable plant, particularly as far as foliage is concerned. Leaves are generally rounded but may be ivy-shaped. Upper leaf surface colour varies from plain green with more or less paler markings, through markedly more variegated forms. In some variations, which are particularly attractive to my eye, silver colouration predominates, with or without a dark green edge.  The undersides of the leaves may be plain green, through darker shades to beetroot red.

Flowers are propeller shaped, predominantly mid pink with deeper markings around the ‘mouth’. But there are forms with colours varying from darker pinkish magenta through to nearly pure white, with darker markings.

The Cyclamen coum complex

The species, Cyclamen coum, has been divided into many subspecies, forms and varieties, which is confusing for most gardeners who just want to grow a good plant. This confusion arises partly because few have studied the plant throughout its wide geographic distribution in Eastern Europe and the Middle East. Those who have report that many if not all of the named variations may sometimes be found growing side by side in single locations! For practical gardening purposes, plants labelled as Cyclamen abschasicum, C. caucasicum and C. hiemale are all just subspecies, varieties or forms of C. coum.

As C. coum has been in cultivation for several centuries it is not surprising that many ‘superior’ forms have been selected, named, propagated and distributed among gardeners.  In some cases they have been developed into pure breeding lines that come true from seed. One of the best is C. coum ‘Pewter Leaf’, which seeds around freely in my garden with very little noticeable variation in the seedlings.

Cyclamen pseudibericum

This distinctive close relative of C. coum only occurs in the mountains of south-west Turkey. It is a plant of open woodland and scrub on rocky ground, in areas that have a higher rainfall than most of Turkey and adjoining Syria. It sometimes grows alongside Cyclamen coum, but does not seem to hybridize with it.

Cyclamen pseudibericum is a bigger and more imposing plant with larger, well marked leaves and larger flowers to match. The blooms are most often dark magenta with an even darker blotch at the mouth of each petal, with a white ‘V’-shaped marking. There is also a paler pink version which has similar petal markings. The flowers of both forms produce a delicious honey fragrance.

Cultivation

Cyclamen pseudibericum is by no means common in gardens and is quite expensive to buy. You are more likely to see it exhibited in a pot at an AGS Show that in someone’s garden, partly because it is generally considered to be frost tender. In some gardens at least this is far from true.

The illustration above shows the two principal colour forms growing side by side in John Lonsdale’s fabulous woodland garden in Exton, Pennsylvania. There it withstands temperatures down to -20˚C without appreciable damage.

Cyclamen pseudibericum starts to flower in the open here as C. coum is finishing. Like all cyclamen, you can easily raise it from seed. As its native habitat suggests, it grows best in a semi-shaded position where the soil remains moist but is never waterlogged. It is also an excellent pot plant; a well-flowered specimen, such as the prize-winning plant shown here, will fill a small alpine house with its sweet perfume.

Cyclamen repandum

This charming plant in its many forms is fairly widely grown in gardens as it is another of the reliably hardy species. Like C. coum, it has been cultivated for at least three centuries and is easy to cultivate in similar conditions, though it is less tolerant of drought at the root.

It has become naturalised over a long period in some of the famous woodland gardens of Britain, including National Trust, Knightshayes, in Devon. I have a vivid memory of seeing hundreds if not thousands in full and glorious bloom on an April visit there some twenty years ago.

Equally imprinted on my mind’s eye is a population of closely related, Cyclamen rhodium subsp. peloponnesiacum in dappled sunlight on the banks of a stream in the Greek Peloponnese. Both species have dark green leaves more or less heavily spotted with paler green or cream markings. I also found Cyclamen rhodium growing in rocky ground in quite dense shade on the island of Rhodes.

Typically, as can be seen from the illustrations, flower colour is generally some shade of pink, darker in typical C. repandum than in subspecies peloponnesiacum. The Rhodes form, on the other hand, is almost exclusively white. All are excellent garden plants.

Cyclamen libanoticum

This, one of the most beautiful of cyclamen, occurs in the wild only in a few scattered locations in the mountains to the north-east of Beirut. There it grows at quite high altitudes (750-1400m) among rocks in the shade of trees and shrubs. Fortunately, because of this, and contrary to what was thought when it was first cultivated in the 1960s, it is surprisingly hardy. As is to be expected, given its very limited range in the wild, it is much less variable than more widely distributed species. This applies to both leaves and flowers.

The leaves are larger than most and borne on longer stalks, giving the plants quite a lax appearance. The flowers too are larger than those of most species cyclamen. All that I have seen are uniformly a lovely soft pink, with magenta markings at the mouth. Unlike most cyclamen, which are either sweetly scented or have no discernible scent, C. libanoticum has a rather unpleasant odour.

Cultivation

In my N. Wales garden Cyclamen libanoticum thrives outside without protection. I grow it in well drained, rather stony soil in part shade provided by deciduous trees. A regular mulch with well rotted leafmould is beneficial. With me its flowering overlaps that of C. repandum, generally coming into bloom in late March.

I have never been fortunate enough to have C. libanoticum seed itself around in the garden as most other species do. But seed is set freely and germinates well when sown in a pot as described earlier. The seedlings are more precocious than those of most species, often flowering in their second season of growth.

Because its leaves with their long petioles have a habit of flopping on the ground, C. libanoticum is not one of the most effective pot plants.

Cyclamen purpurascens (syn. C. europaeum)

In our garden there is a lull between the end of flowering of the ‘spring’ species, and the arrival of Cyclamen purpurascens, usually in July. This species is perhaps the most elegant small cyclamen, with very sweetly scented flowers.

Given that in the wild it has the most northerly distribution of any species, it is not surprising that it is very hardy. As its former name indicates, most of its wide range is in Europe. One small separate population occurs in the Caucasus mountains (ed. described as Cyclamen colchicum)

Throughout its homelands it is chiefly a plant of sub-montane woodland. It favours beech or hornbeam forests, sometimes occurring in mixed broadleaved and coniferous stands or even in more open situations. It mainly occupies humus-rich soil among rocks.

The tubers of Cyclamen purpurascens are more knobbly than those of other species. They often bear trunk-like protuberances from which leaves and flowers grow.

As indicated earlier, the species with a wide geographical distribution tend to be more variable than those with a more limited range. Cyclamen purpurascens has a number of good regional forms. My favourite is a silver-leaved form growing in the area around Lake Garda, in Italy.

Cultivation

It might be thought that C. purpurascens, which often occurs in quite large populations in the wild, would be easy to grow en masse in the garden. If so, I have never witnessed what would provide an olfactory as well as visual delight. But Cyclamen purpurascens is not difficult to cultivate, it just rarely deigns to seed itself around. Because of its size, in my experience it grows best in a raised bed or trough. This also enables one to sniff the sweet perfume at will.

In the wild the tubers grow chiefly in stony soil or deep rock crevices. Because of this you may read advice to plant it deeper than other species. But in my experience it grows equally well with the tuber at or near the soil surface.  Like most cyclamen, it also makes an excellent pot plant.

Cyclamen purpurascens is straightforward from seed, although the tiny (2mm wide) first year tubers are vulnerable. Ensure that the compost in the pots is kept moist, and slugs and snails are kept at bay..

Cyclamen cilicium and C. mirabile

These two closely related and similar looking autumn-flowering species come from Turkey, but from different habitats. Cyclamen cilicium is a sub-montane species from open woodland and rocky scrub habitats with appreciable summer rainfall. Cyclamen mirabile grows in more open, sunny sites at lower elevations which are much drier in summer.

Reflecting these differences, C. cilicium is the hardier of the two. The species is more tolerant of summer precipitation, and therefore easier to grow outside in Britain.

I have given up trying to grow C. mirabile in the garden. However, it makes an excellent pot plant, especially the forms with particularly eye catching foliage. The leaves generally show a faint pinkish flush as they develop, that fades as they age. But in the best horticultural selections, such as Cyclamen mirabile ‘Tilebarn Nicholas’, a much stronger pink marginal zonation is maintained, if somewhat diminished, throughout the leaf’s life.

Cultivation

As indicated above, Cyclamen cilicium is quite happy and long-lived outside in the UK. Some of my plants are over 10 years old. It seems to prefer a rather open site with good drainage. Flowering period is prolonged, starting in September, with the odd flower often produced into early November. It is not a particularly eye-catching plant either in foliage or flower, but repays close attention.

The individual tubers are of moderate size, 5cm diameter being about the largest. The roots arise only from the bottom of the tuber. It produces seed quite freely, and self-sown seedlings pop up here and there.

Cyclamen hederifolium (syn. C. neapolitanum)

This is everyman’s cyclamen. Extremely hardy, it grows in almost any soil and situation. It will never fail to produce a bountiful, long lasting crop of flowers from August onwards into autumn.

Not only that, as already mentioned and illustrated, it has some of the most variable and interesting foliage of any cyclamen. And the leaves last in good condition for at least nine months. What more could you ask of any garden plant?

There is a huge number of distinctive forms in cultivation. Avid cyclamen enthusiasts and nurserymen have developed many forms over the years. Some of them have been carefully selected to breed true, and given cultivar names. All are well worth their place in the garden. Special mention must be made of those with white flowers (Cyclamen hederifolium ‘Album’), which are rarely found in the wild but common in cultivation. This is not surprising because the best ‘whites’ are perhaps especially beautiful. Some of the white forms come true from seed, so a colony can be built up quite easily. They look particularly stunning growing among trees.

Cyclamen hederifolium was for long known as C. neapolitanum, the latter name referring to its early introduction from the vicinity of Naples. It in fact has a wide Mediterranean distribution from south-east France eastwards to southern Turkey, including mainland Greece and many of the Greek islands. It grows in a range of habitats including woodland margins and glades, open scrub and maquis (dense scrubby coastal vegetation), sometimes in amongst rocks.

cultivation

One of the great pluses of Cyclamen hederifolium is its ease of cultivation. Perhaps it is most at home growing in the notoriously difficult position in the partial shade of large deciduous trees. Here, it will increase annually from self-sown seed. It also tolerates the shade of tall buildings without fuss. The plants will appreciate an occasional top dressing with well rotted leafmould, or other organic mulch. But you can also grow it well in any other position, in acid or alkaline soil, provided the drainage is good.

A good way to develop a colony is to grow plants from seed. This is widely available in the trade as well as in the seed lists of the AGS and Cyclamen Society. But every potful of seedlings is likely to produce plants with a plethora of interesting and attractive leaf variations.

Pests and Diseases

Hardy cyclamen are generally mercifully free of pests and diseases, whether grown outside or under glass. I have never needed to take any specific action to keep plants growing in the garden healthy. In pots you may need to control the usual glasshouse pests, especially aphids (both leaf and root) and weevils.

Aphids

Leaf aphids are easy to deal with, provided colonies do not get out of hand. Primula root aphids (white colonies attached to the roots and in the surrounding soil) are more difficult. If a plant looks stressed or looses its leaves prematurely for no obvious reason, assume the worst. Turn the plant out of its pot and check the roots. If aphids are present (usually white with a waxy deposit around them), first wash off all the soil. Then cut back badly affected roots. Treat the remainder by submerging the roots for about 30 seconds in a solution of pyrethroid insecticide, diluted as instructed. Wash off the residue and replant in clean soil.

If you have other members of the primula family growing in pots in the same glasshouse, I would advise treating them likewise. In cases of bad infestation (rare in my experience) you may wish to consider sacrificing the plants and starting again from seed.

Weevils

Vine weevil larva (x8)

Two similar species, Vine weevil and Clay-coloured weevil predominate in the UK. They can be very damaging to a wide range of plants both in the open garden and in the glasshouse. It is the larvae that do most of the damage. They are small (1 cm long) sickle-shaped grubs with brownish heads that browse the roots, and in the case of cyclamen may attack the corms. Above ground symptoms of their presence are much as for root aphis (above). If you turn the plants out of the pots and remove the compost you can remove them manually. You may see the adult weevils around the greenhouse; small clay-coloured beetles. Keep an eye out, especially in the evening and early morning, and remove them by hand.

Conclusion

I hope that this tour of the world of hardy cyclamen will inspire you to give them a try. There can be few plants for the smaller garden that will give as much satisfaction with so little input. If you succeed with Cyclamen coum  and Cyclamen hederifolium, you will hopefully be encouraged to try some of the other, less commonly grown species.

And if you fancy growing some of the less hardy species with winter protection, a wide world of interest awaits you. Perhaps you will even be tempted to bring some of your best plants along to one of our AGS Shows. They take place throughout Britain from the early Spring to the late autumn, so there is likely to be at least one near where you live.