Cyclamen persicum- Florist's Cyclamen

Cyclamen is an unusual plant with dark green, heart-shaped foliage and butterfly-like flowers in colors ranging from white to light pink, lavender, hot pink, and hot purple.

CULTURAL REQUIREMENTS

Light: Bright light all day with one to two hours of full sun is ideal as long as the exposure is not too hot.

Watering: If possible, water Cyclamen from below, as the corm-like tubers can easily become waterlogged. If you must water from above, water as close to the edge of the rim of the pot as possible; this will avoid any accumulation of water in the center of the plant.

Temperature: The Cyclamen grows best when temperatures can be kept cool during the day and at night; between 60 and 72º F during the day and 50º to 65º F at night. Short lived Cyclamen are the result of warm growing conditions.

Humidity: A relative humidity above 50% is preferred to successfully grow Cyclamen. Provide additional humidity by standing plants on shallow trays filled with moistened pebbles, and/or use a humidifier.

Feeding: Fertilize every two weeks with a water soluble, high phosphorous liquid fertilizer after the dormant period (March to May) is over.

Transplanting: Once the plant stops flowering and the leaves begin to yellow, hold off on watering and keep in a cool location out of direct sunlight. When the leaves easily separate from the tuber, repot it in a mixture of equal parts sterilized houseplant potting soil and perlite. Allow the top half of the tuber to be about ½" above the soil level. After repotting, resume watering and give Cyclamen as much light as possible.

Propagation: Cyclamen is easily grown from seed under fluorescent lights for about 15-16 hours per day. Seeds started in winter will produce flowers in about a year.

Maintenance: When Cyclamen goes into spring dormancy water only to keep corm from shriveling. Remove all leaves gently from corm after they have dried and yellowed and repot into a new pot with fresh soil mix.

Special Note: Always select plants with the most buds, as the blooming cycles will last longer. In the warm dry indoor environments, Cyclamen can be attacked by cyclamen mites, be sure to keep the night temperatures as cool as possible, and provide extra humidity.

Although there are a small number of inter-specific hybrids, the common usage of the term 'Cyclamen Hybrids' or 'Florists Cultivars' refers to intra-specific hybrids of Cyclamen persicum origin.

These cultivars have been bred in a large range of flower colours, including 'double flowers', picotee forms and frilly petals. There are also two basic plant sizes, generally referred to as 'large' and 'small' (or 'mini') forms.

The breeding of persicum cultivars began seriously in the mid-nineteenth century through selection and back-crossing, and resulting in flowers several times larger than the wild species. Much of this work took place in England and the Netherlands and many named forms were produced.

In the 1960's a breeding program at Wye College, University of London, crossed existing large flowered plants with wild forms, producing smaller plants with more refined, scented flowers and attractively marked foliage. These became known as the 'Wye College Hybrids'.

Today, Cyclamen persicum cultivars are mass produced as pot-plants particularly in the Netherlands and Germany, using F1 hybrid seed strains.

Vegetative Reproduction

Cyclamen are plants which spend part of the year in growth, and part of the year in a dormant state, during which there is no living foliage, although is some species fruiting pedicels may remain in a vegetative state as the seed matures. During this dormant period the plant remains in the form of a subterranean tuber, which is in fact a swollen root As a tuber, the possibilities which exist for corms or bulbs do not exist, however, as in the case of a common potato (which is a similar organism), the tuber can be divided provided each portion has both a growth eye and part of the rooting region of the tuber.

This makes this operation more feasible in those species which have multiple growing points, such as Cyclamen graecum. However, since there are inevitable problems in efficiently sealing the cut edges to guard against rot, without the tuber desiccating, division of tubers is not a practical method of propagating plants regularly.

Experiments have been carried out in the use of Meristem culture to propagate Cyclamen, but it is not appropriate to detail this here.

Propagation from Seed

Amongst enthusiasts there is much discussion about the most efficient ways of germinating Cyclamen seed in order to obtain the most consistent and highest percentage of germination. Articles and notes concerning this regularly appear in the Society's journal, and research projects have been carried out by various individuals and organisations.

Click here, or examples of these articles and notes of the Experiences of Members of the Society with seed germination

In 1992 the Society co-operated with the University of Reading, in the UK, who carried out experiments in the germination of Cyclamen seed, without the use of chemical additives, the results are now often referred to as The Reading Method

From the various theories which have been put forward, there are a number of significant features which can be distilled:

  • For consistent germination, fresh seed is required. In some species, it is essential. It should be sown as soon as it is ripe - ideally being gathered just before the capsule splits open - when the seed has coloured to a light brown.
  • Soaking seed in warm water (with a wetting agent, such as a drip of hand dish-wash detergent/washing-up liquid) for about 24 hours prior to sowing, is beneficial.
  • Light acts as a germination inhibitor to Cyclamen. Some authorities state that absolute darkness is required, whilst others claim that heavy shade is sufficient
  • If seed is allowed to dry out after germination has started, this is likely to be fatal
  • There is no benefit to be gained from stratification - in some species, this would be fatal
  • As Mediterranean plants which grow in autumn(fall)-winter-spring, germination takes place generally in cool conditions. From choice, between 13-15ºC (55-60ºF) is ideal.

Since it is recommended that seedling tubers should remain in the same container until they go dormant in their second growing season, it is better to sow in pots rather than in seed trays or flats, so that there is adequate depth. For larger quantities, the blue/black plastic, 15cm (6 inch) deep boxes used for packing mushrooms, are ideal in a non-commercial situation.

The compost used should be similar to that used for potting Cyclamen tubers, but with a reduced level of fertiliser. Certainly, it should be free draining but moisture retentive - which indicated a significant proportion of grit, plus some organic matter.

The seed should be sown on the surface of the compost, spaced about 2cm (¾ inch) apart, and covered with a layer of grit about 5-7mm (¼ inch) deep.

In general, autumn (fall) flowering species will germinate in the autumn. Spring flowering species will germinate in the spring. A very obvious exception is Cyclamen purpurascens, which has a long flowering to germinating cycle. Usually, it will flower in the summer of year 1, the seed will ripen in the summer of year 2, and if sown immediately, the seed will germinate in the summer of year 3.

However, if no seedlings are seen within the first 12 months (for any species), the pot should not be discarded as seedlings can appear 2-3 years later. This is particularly true when the seed has been subjected to dry storage or is old.

Gibberellic Acid

Gibberellic Acid (GA-3) can be used horticulturally to combat germination inhibitors and break seed dormancy. The Cyclamen Society has not yet carried out trials with GA-3. Opinions as to its use with Cyclamen seed differ, and whilst there are those who maintain that generally there is no particularly beneficial effect, and that seedling growth can be weak, GA-3 is in regular commercial use in at least one nursery, who report as follows:

"Seed is sown as dry stored seed, not fresh, and in some instances is several years old. We treat all our Cyclamen by soaking in a 500 to 1000 parts per million solution of GA-3 until the seeds have swollen (usually 24-48 hours). The seed coats are fairly hard, and if the hormone does not get in, it will do little good. It is possible to overdose the seed if you forget to remove it from the soak. The seed is then planted out in a lightly shaded greenhouse. We always cover with a grit layer but this does not exclude light. Germination is much more rapid than by any other means we have tried and we have never had any problems with etiolation or difficulty growing on. Indeed Cyclamen are amongst the easiest of plants to deal with when treated with GA-3. The resulting plants grow on at several times the rate of untreated seedlings and it is not unusual to produce a flowering size plant in a few months as opposed to the pea sized or smaller tubers that often result from conventional sowing.

We have done repeated trials with hormone and no hormone seed from a variety of sources and the results are always the same. It is not so much that the percentage of seed that actually germinates is higher, although it may be 10-20% better, but the time delay waiting for leaves to appear is much shorter. Untreated dry-stored seed may appear over months and even 2-3 years later we find a few seeds still germinating. With hormone all the viable seeds come up simultaneously. This is a great advantage to commercial growers."

It has also been reported that soaking in a dilute solution of GA-3 can be used to break tuber dormancy, and force two or more growing cycles per year, but no more information is available on this.