These notes are reprinted from the Society's journal as examples of the discussion which occurs and gives an idea of the experiences of ordinary members of the Society.
Members write to the Journal more often about seed sowing success and failure than about any other topic. Many of the contributions below describe the experiences of Society members in the light of the University of Reading's work for the Society on seed germination. As reported in the Journal (June 1993, p2), this "Reading method" showed that for at least C. hederifolium and C. graecum success depends on complete absence of light for 15 to 26 days, a temperature of 15°C (59°F) and certainly no higher than 20°C (68°F), and a constant supply of moisture without flooding, drying out, or even minor fluctuations. None of these accounts can claim to report a valid scientific experiment, with detailed records of light conditions, temperature and dampness, and with exact comparisons between treated and untreated seeds. So we have made no attempt to give a pseudo-scientific look to what follows, for example by trying to pull together all the different accounts into a single report, or even by editing individual accounts into a standard pattern. Instead, we have tried to let people's own words speak for themselves, so as to preserve the feel of an informal discussion about seed raising problems and successes. However, to make it easier to "drop in" on this discussion, we have prefaced each contribution with a short summarising comment.
Joan Whelan finds it improves germination of C. cilicium, C. coum and C. intaminatum, but perhaps not of C. purpurascens
All seeds in this experiment were from AGS and St Andrews Botanic Garden seed distributions. None was fresh. They were soaked in water and washing-up liquid for 12 hours before sowing. The pots were then placed in a closed polystyrene container on 2.5 cm (1 in) of damp grit. The container was placed in a dark cupboard under the stairs where the temperature remained fairly constant at or slightly below 15°C (59°F).
A control group of the same species and numbers of seeds was similarly pre-treated and placed in pots in an open cold outdoor plant house. The compost in both cases was a 50/50 mix of John Innes No 1 and coarse grit. Each pot was topped with grit.
All seeds were sown on 16 January 1994. Germination was as shown in the Table (the numbers after each date show how many seedlings had emerged). After the first germination indoors pots were taken out of the dark, gradually hardened off, and put out in the cold house in June 1994. As the Table shows, all species in the indoor group except for C. purpurascens germinated in larger numbers than the outdoor group, and even C. purpurascens did at least start germination earlier.
|Table: Germination Dates||Indoors||Outdoors|
|C. cilicium (20 seeds)||26 February||5||19 September||2|
|8 March||8||27 September||4|
|C. coum (20 seeds)||26 February||4||18 September||1|
|7 March||7||27 September||4|
|C. intaminatum (20 seeds)||26 February||1||27 September||0|
|C. purpurascens (16 seeds)||22 May||1||8 July||1|
|23 July||3||27 July||8|
|27 September||14||27 September||15|
Mrs E Ray finds the Reading method very successful, though some species are quicker than others
I usually receive six or eight seed packets from the Society and four or five might germinate during the next few months.
On 21 September 1993 I placed my seeds in six little pots in a biscuit tin at room temperature, and watered them just a little every week (which was fairly difficult in a completely dark room). Exactly four weeks later I opened the tin in dim light and I saw tiny seedlings in two pots. Those I placed on the windowsill and took the other four out of the tin, putting them in a dark corner of the room with glass and cardboard over the top; soon more seedlings appeared in those pots. All six varieties germinated, the last lot on 15 November 1993. They appeared in this order: C. pseudibericum, followed by C. cilicium album, C. persicum, C. cyprium, C. libanoticum, and finally C. creticum. This was the best result I have ever had. It was repeated in 1994 using the same method, when all eight varieties sown germinated successfully.
Hermann Betzi finds the Reading method works well even on previously sown seed; small departures from it prevent success; grit topping helps seedling development
From mid-June 1993 I used the Reading method on my own seed, soaking it in water and sowing it in clay pots some millimetres below the surface, in a black plastic bag in a room with the temperature held between 15° and 18°C (59-64°F). I deviated from the method by opening the bag frequently to put in new pots, by watering some pots with water of varying temperature, and so on. I had 34 pots of 13 species, including 22 pots sown from March onwards which had not yet germinated.
Germination started from 3 July and eventually I had at least 50% germination in each pot - at least 80% in most. There was no significant difference between the 22 pots sown earlier and the newly sown pots, from the end of June onwards. Germination times however were not regular, varying between 1 and (for C. repandum) 4½ months.
I then used the method on Society seed, following it more exactly: I watered the pots once at sowing on 15 September and then kept the bag closed for four weeks. Results were as follows:
|.||First Germination||Total Germinated|
|C. coum (5 seeds)||26 October||5|
|C. coum 'Nymans' (10 seeds)||26 October||6|
|C. pseudibericum roseum ( 9 seeds)||26 October||8|
|C. repandum album (16 seeds)||26 October||7|
|C. creticum (9 seeds)||1 November||6|
I used the method on a second batch of Society seed, sown on 27 December. However I did not adhere as closely to the method: I forgot to soak the seeds; I moved the pots from one room to another, adding water at that time (when light could have reached the seeds); and though the temperature was held between 14 and 18°C (57-64°F) for the first three weeks, it subsequently fell from 15 to 12.5°C (59-55°F).
By February 1994 there had been at least some germination with all species tried: C. hederifolium, C. intaminatum, C. libanoticum, C. persicum and C. repandum peloponnesiacum. Germination rates were encouraging, though less uniformly satisfactory as with my own fresh seed, or with the September sowing when I followed the method more exactly. However, I added a grit topping to this last sowing, and found that all seedlings developed a very fine first leaf. In my experience, without grit the remaining seed shell often hampers the development of the leaf for a month or more, sometimes severely.
Peggy Bocking finds that even with careful temperature control C. pseudibericum, C. repandum and C. trochopteranthum are reluctant to follow the Reading method
In August, I spaced my own C. hederifolium seed out in trays filled with seed compost and covered very lightly with a fine compost grit. I then covered the moistened trays with two layers of moistened capillary matting and enclosed them in polythene bags, I then placed the trays in a heated propagating frame, in a greenhouse. Moisture and darkness was easy, but I found keeping the correct temperature difficult. I had set the temperature at 15°C (59°F), but if there was any sun during the day, I found that although the heat had automatically switched off, the heat inside the frame had risen to 21°C (70°F) or above. After four weeks, finding no sign of germination I removed the trays from the frame and stood them under a bench in the dark. They started to germinate in the winter, but were erratic.
When the Society's seed arrived I used the same basic sowing method, but this time took the trays into the house, which has electric under floor heating. I put the trays in dark places in the hall (under any suitable furniture), and set the temperature at 16°C (60°F).
I have been very pleased with the results. I have had 80 to 100% germination with C. graecum, C. hederifolium, C. cyprium, C. cyprium 'ES', C. cilicium album, C. coum 'Nymans', C. coum 'Maurice Dryden', C. balearicum. However, C. repandum, C. pseudibericum and C. trochopteranthum had still not germinated by the end of the year.
Mark Griffiths finds loam-based compost better, and categorises species by germination success
My first year of growing from seed (1990) I used a peat-based seed compost. I soaked the seed for 24 hours in warm water with washing-up liquid, then covered the surface of the compost with silver sand, put the seed on the sand, covered it with a thin layer of seed compost, and put the pot in a plastic bag.
All following years I have used a loam-based seed compost (or JI 3 with added grit). I still soak the seed but place it directly on the surface of the seed compost and cover with a thin layer of coarse grit. The rest of the process is the same. The change in procedure followed poor results from the first method. A number of pans had failed to germinate. Though they then germinated in autumn 1991, the plants in the peat-based compost have not grown as well as those in the loam-based compost. As a number of species had failed to show by summer 1991, I asked for them again from the 1991 distribution. The 1991 sown seed mostly came up the same autumn, and has overtaken the 1990 seedlings in size (even those few 1990 seedlings that appeared).
I have split my results so far into broad categories. All seeds are from the Cyclamen Society unless otherwise stated. The number after the species name is the approximate number of sowings. Quick means up in the autumn or winter after sowing.
Good and quick germination: C afticanum x hederifolium (1); C. afticanum (2); C. cyprium normal and 'ES' (2, own fresh seed); C. graecum (1, commercial source); C. purpurascens silver marked (1, own fresh).
Quite good and quick: C. coum CSE (7); C. coum caucasicum (2 - generally a bit poorer than "normal" coum); C. intaminatum patterned leaf (2); C. libanoticum (1).
Fairly slow (several months) and reasonable germination: C. balearicum (2); C. creticum (3, but CSE Karpathos seed has produced only a single seedling after a year or so); C. purpurascens (1); C. pseudibericum (2); C. repandum (2 - fair germination); C. repandum peloponnesiacum (2); C. repandum rhodense (1); C. trochopteranthum (1).
C. cilicium took a year, probably as seed was not soaked before sowing, but germination was then very good the following autumn. C. graecum has so far produced just one seedling. C. repandum album's first two seedlings appeared winter 1994 after sowing 1992. C. repandum peloponnesiacum vividum (CSE seed) has one up now from 1994 seed. C. rohlfsianum has been poor, one sowing no germination, but usually one seedling per sowing in first season, occasionally others later. C. parviflorum from CSE seed (1990) produced one seedling that winter, and one further seedling each succeeding winter. C. persicum has been rather variable - some good and quick, e.g. "standard" persicum, pink forms and persicum album. CSE seed of it has been very variable: only one S2 N90109 since sowing in 1992, other numbers have come up well, some others only germinated this year, and some have yet to germinate at all from 1992 sowing.
Stina de Graaf finds steady temperatures in the dark suit most species, but not C. purpurascens; seedlings indoors grow better than those outside
In 1993 I sowed most of the seeds in the usual way, outside in pots with a gritty porous mixture, but with C. purpurascens, C. intaminatum, C. coum roseum and C. coum caucasicum I tried to copy the Reading method.
We have a large cupboard under the stairs in which the temperature is very constant. There is hardly any difference between the temperature by day or night: in September it is about 18°C (64°F), in midwinter about 16°C (61°F).
I sowed the seeds, five or six of each, in a tin lined with black plastic. After sowing and watering I closed the tin and stored it in the cupboard. The first seedlings appeared after five weeks and most seeds had germinated after ten weeks, apart from one C caucasicum seed - but only one C. purpurascens seed germinated. These results were much better than with the outdoor sowings.
In 1994 I gave all the seeds the indoor treatment sowing on 4 October. By the end of January I had the following results: C. cilicium (40 seeds) 35 seedlings; C. cilicium album (9 seeds) 6 seedlings; C. coum 'Maurice Dryden' (12 seeds) 11 seedlings; C. trochopteranthum (10 seeds) 4 seedlings only; C. hederifolium 'Bowles Apollo' (13 seeds) 12 seedlings; C. hederifolium arrowhead form (17 seeds) 16 seedlings; C. coum 'Linnet strain' rose (25 seeds) 24 seedlings. As I love experimenting I kept some seedlings indoors and some I put in a small cold frame. The indoor seedlings are definitely performing better, developing second and third leaves. The outdoor seedlings have only their first leaves.
Gwen Baker finds temperate darkness a success too - but for her the hot summer and wet autumn of 1994 made outdoor germination good too
In my hall I have an old wooden trolley at the foot of the stairs, the top bears houseplants, the bottom holds bits and pieces of plant equipment, dormant plants etc. On this shelf I put a gravel tray with well soaked Hortag granules to maintain a humid atmosphere, put my seed pots on top and covered them with a seedtray, perforated so that the air would not stagnate - so dark, but not 100% light-proof I reckoned the radiators' heat would escape up the stairs, maintaining air temperature at about the right level.
The germination, admittedly of my own seed sown fresh and soaked to remove the sticky stuff, has been my best yet. I have two small plastic pots of C. coum so thick with seedling leaves it is difficult to count them, at least 35 in each, and judging by the spacing I think I must have got almost if not quite 100% germination. I put them on the kitchen windowsill, where I could count and water them as the spuds boiled (must counteract the boredom somehow), and germination continued in the light. When a pot of C. libanoticum showed its first waving fist I moved one pot of C. coum on to a cooler windowsill in my leanto, which slowed the germination up a little, though three months later it had caught up. Next came a pot of C. pseudibericum. As it seemed so successful a method I moved into the gravel tray pots of C. repandum and C. repandum peloponnesiacum I had sown last year from seed exchange seed; they have germinated but tardily, my one C. repandum has a long thin neck like Scilla (or perhaps Charybdis) and there are two peloponnesiacum only just through - but success after years of nothing!
However, I am not absolutely convinced it was the seed sowing technique, as a pot of C. coum, which I am told by the label was re-potted in August, has 24 seedlings come round the parent tuber in the cold greenhouse. The seeds must have been in the grit which I transferred from the old pot. All germination of C. hederifolium in the garden has also been phenomenal, over 110 lifted from one loose pocketful of leafmould, and a second pocket with as least as many. So perhaps the weather conditions have been just right this year, very hot followed by very wet.
Mary Saunders gets excellent results from the Reading method, even with year-old C. purpurascens seed
In autumn 1993 I sowed 30 packets of seed from the seed exchange in darkness and at around 15°C (59°F). Our north-facing conservatory provides ideal temperatures through the winter, and the pots are placed on the lower shelf of an aluminium staging around which I wrap black polythene to keep out the light. By the end of February 1994 I had germination in all pots, with 100% germination in some, and over 70% in 19. The first showed germination signs after 14 days (all the seed had been soaked in washing-up liquid and warm water for 24 hours) with all pots showing germination after 59 days. The temperature range and number germinated were noted carefully. The maximum temperature was 17°C (63°F), the minimum 9°C (48°F). Two trays of home-collected C. purpurascens seed originally sown in Sept. 1992, which had shown no signs of germination, were also put under the staging in darkness at the same time, and germinated in large numbers by February 1994.
Number of days to first germination for the other species and varieties were
31 days - C. cilicium album, C. hederifolium silver leaf,
33 days - C. graecum 'Windmill', C. hederifolium scented, C. persicum from Karpathos, C. rohlfsianum;
36 days - C. coum pewter/pewter with red edge, C. cyprium, C. hederifolium 'Bowles Apollo', C. intaminatum patterned, C. mirabile silver leaf, C. persicum pink flower;
44 days - C. coum 'Maurice Dryden', C. libanoticum, C. mirabile pink leaf, C. trochopteranthum;
48 days - C. coum pewter blush, C. intaminatum plain leaf, C. intaminatum patterned (pink eye), C. repandum peloponnesiacum vividum;
54 days C. intaminatum pink flower, C. repandum peloponnesiacum;
59 days - C. pseudibericum.
Two pots of C. balearicum did not germinate that year, but germinated in autumn 1994.
Incidentally, by autumn 1994 some C. cilicium, C. hederifolium, C. intaminatum, C. mirabile and C. trochopteranthum from the 1993 sowing were already flowering.
Alan Toothill's seeds did not germinate until he took them out of the bin bag after 36 days of darkness
I tried to keep to the Reading method as closely as possible with Society's distribution seed of C. cilicium album, C. hederifolium album and scented, C. intaminatum plain and patterned, C. persicum Israeli Expedition seed, C. purpurascens and C. repandum album. The seeds were all sown in one large tray of damp peaty grit at 15°C (59°F), double-wrapping the autumn-sown seed tray in a black bin liner, under the greenhouse staging and away from direct light. I looked first after 26 days, then again after another 10 days - not one seedling. So off with the bin bag and back to the full light of day, keeping the temperature at 15°C. Within four days I saw seedlings, and by December I would estimate I had 75-80% germination.
Helena Wiesner, unable to control temperature, finds three weeks of darkness consistently improves germination of C. coum and C. hederifolium
I sow large quantities of C. coum and C. hederifolium seed in a large very well ventilated double polytunnel. With my 1993 sowings I matched some samples of seed from the same source sown on the same day in adjacent beds of the same compost. The seed had been soaked first (in other tests I have confirmed that this speeds germination, and, once dried, the seeds are easier to handle).
In each of these matched pairs one bed was covered closely with thick polythene, white on top and black below, for 21 days. The darkness was interrupted, in that the beds were watered overhead on the first three days.
The total number of seeds sown in these ten pair comparisons was, to the nearest thousand, 37,000 C. coum and 58,000 C. hederifolium.
As these seeds were sown between 9 and 21 August, the temperature in the following weeks often considerably exceeded the Reading guidelines. However, in every paired comparison the seeds which had been covered germinated significantly more quickly than those which had not. On average, the number of days to first seed leaf for each bay was 42 days for C. hederifolium covered, 52 days uncovered; 56 days for C. coum covered, 73 days uncovered. By the end of January 1995 seedling growth in the beds which had been covered was in almost every case better than in the paired uncovered beds, as judged by a visual assessment of the amount of ground covered by foliage.
Dr Michael Balsdon finds species take between three weeks and twelve or more weeks
In Santiago I sowed Society seed in late September 1993 (equivalent to a warm spring in the northern hemisphere). I had germination in about three weeks with C. africanum, C. graecum and C. graecum album; in about six weeks with C. hederifolium, C. libanoticum, C. repandum, C. rohlfsianum and cultivar C. persicum; in about ten weeks with C. balearicum, C. cilicium, ordinary C. coum, C. creticum, C. mirabile and C. pseudibericum; and in about twelve weeks with C. coum 'Nymans' and pewter, C. cyprium and C. trochopteranthum. I had no germination within the year with C. intaminatum patterned leaf or with C. purpurascens silver leaf.
P L Elphick found quicker germination from December sowings than from September ones, on damp tissue
On 11 September 1993, Cyclamen Society seed was soaked in tepid water with one drop of detergent added to each dish for two days, then placed on wet tissue in a two-litre ice-cream container which had been washed with boiling water. The container was put on a shelf in a brick outhouse, where the temperature fluctuated around 16°C (60°F). The only success was C. rohlfsianum which germinated 100% on 7 October 1993. Most of the other seed grew mould and the experiment was abandoned.
For 1994, a 2 litre ice-cream container was washed in a weak solution of household bleach, then rinsed under the tap. The seed, after being treated to a bath in warm detergent solution for 24 hours, was rinsed first in tap water, then a fungicide solution. The seed was then spaced in rows on to tissue soaked in the same strength solution. Seed was sown on 22 September and the container was placed in my brick outhouse. The temperature started at 18°C (65°F), falling gradually to 16°C (60°F) by 11 November. At the time the container was taken into the house and put into a cupboard, where it has been a fairly constant 16°C (60°F). By January 1995 I had had good germination with C. balearicum and C. mirabile, only one seedling with C. creticum and C. parviflorum and nothing from C. pseudibericum, C. trochopteranthum and C. purpurascens.
On 19 December 1994 more Society seed was sown after the same preparation as before. The container was placed in the same cupboard as before at around 16°C (60°F). By the end of December C. pseudibericum, C. coum caucasicum, C. cilicium album and two forms of C. graecum had all germinated, all except for C. pseudibericum very well.
This comparatively good rate of germination makes me wonder if it is not best to leave seed sowing until conditions are tight, rather than sow in late summer when the temperature is too high.
Margaret Fleming has excellent germination with interrupted darkness
On 7 September 1992 I received Seed Distribution C. coum pewter leaf and 'Tilebarn Elizabeth', C. graecum, C. intaminatum, C. mirabile, C. parviflorum, C. pseudibericum and C. repandum album. These were sown the same day in 14 cm (5½ in) plastic pans of gritty seed compost. They were put inside plastic bags with stout wire hoops to hold the bags off the compost, closed with clothes pegs to facilitate inspection, and put in a north-facing frame in my Thames Valley garden. They were then loosely covered with a large empty compost bag cut open to show the black lining, which was put face down on the pans. When occasion required the plastic was removed and the bags opened to allow rain to refresh the compost or condensation to evaporate, but this was replaced before nightfall.
On 4 October C. graecum began to sprout and was followed by the others, including C. pseudibericum on 11 November. The last to germinate wasC. repandum album on 4 March 1993.
By the end of December the black plastic was removed and the leaves were growing strongly. As the weather was colder all the pans were moved to a cool greenhouse kept at a minimum of 4°C (40°F), where they were kept in the light. On 20 March 1993, as the weather was warm, C. pseudibericum and the hardier species were put out in the frame, and kept growing on through the summer. Germination of all species would appear to have been at least 90%.
John Rickard finds darkness the most troublesome ingredient of the Reading method
Aiming for moisture, darkness and a mild temperature, my main trouble was finding a suitable dark place and container. I soaked the seed in diluted washing-up liquid and then sowed it in small pots of peat-based compost, putting them on plastic tea trays in double black plastic bin liners, and putting those in the dark, under the work bench.
This worked well in terms of germination speed and numbers. However, to keep the un-germinated pots as dark as possible (even a fleeting glimmer of light is said to reduce effectiveness) I did not look at them often. Many seedlings developed stems about 14 cm long (5-6 in): not a good idea, though the plants continued to develop after being brought into the light.
My conclusion is that to get the benefits of darkness without long weak stems it is important to keep individual seed pots separate.
John Stirling finds pregermination on capillary matting works well with most species, and adapts conveniently to the Reading method
In autumn 1991 I set up experiments to follow the work reported in the Journal (June, 1991) by AJ Jackson. My experiments were housed in a cupboard in a spare bedroom. They were started when the room temperature had dropped to less than 15°C (59°F) in mid September. The domestic heating system was then used to obtain as near 15°C as possible. A temperature range of 14 to 16°C was maintained for most of the trials. Extremes of 12 to 18°C (54-64°F) were recorded during a holiday period.
The seed was prepared by soaking and washing in water for 24 hours before being placed between saturated capillary matting, and then sealed in a clean plastic food container. (Kitchen paper was used for small quantities of seed but was found to support mould growth much more than capillary matting). The seed in all cases was germinated in total darkness at about 15°C. A few days after germinating the seed was planted singly in a 4 x 4 cm pot (40 to a standard seed tray) and grown on at 15°C in a greenhouse. Planting depth in all cases was kept to the minimum possible.
My success was better than in previous years when seed was sown direct into compost in seed trays. Much more time was needed, but better use was made of the limited heated space available in the greenhouse, and it is a way of removing individual seeds from the darkness as they germinate. This method can of course only be used in the winter, when temperatures are low enough.
|.||Number of Seeds||Number Germinating||Days to Germinate|
There were some individual disappointments. In many cases the first leaf had difficulty in shedding the seed coat. In general, small-seed species did not do as well as large-seed ones, with nearly half the germinated C. balearicum and intaminatum and all the repandum failing to establish. Seeds which retain their golden brown colour when germinating usually grow on to produce strong plants. Where the seed goes a dark colour it may not germinate or if at all generally dies early in its life.
Stephen Blore finds seedlings germinated on it slower to establish than those germinated in compost
I also tried out A J Jacklin's method, in September 1991, with seed from the Society's distribution: (C. purpurascens labelled 'Limone'), C. coum 'Nymans', C. libanoticum and C. balearicum. At the same time for comparison I sowed seed in compost in clay pots, putting them into plastic bags alongside the plastic boxes containing the seeds on capillary matting. The pots and plastic boxes were put in the dark at a temperature of around 16°C (60°F). All seed was sown 22 September. The results were as follows (days to germinate are not strictly comparable, as the figures for pots are based on seedling emergence from the soil, not just radicle emergence):
|Capilliary Mat||In Pots|
|Seeds Sown||Seeds Germinated||Days to Germination||Seeds Sown||Seeds Germinated||Days to Germination|
|C. coum 'Nymans'||8||7||18||66||10||7||51|
All seeds were removed from the capillary matting as soon as germination commenced as shown by emergence of radicles, and put into the same compost as in the pots. However, the seedlings produced from capillary mat sown seed were slower to get established than those sown direct in compost in pots, and the plants smaller.
Plants of C. purpurascens raised from compost-sown seed flowered first in September 1992 and again in 1993. One tuber was then 3.25 cm (1¼ in) in diameter; the largest of the capillary mat sown plants was only l cm (under ½ in) in diameter. Compost-sown C. balearicum flowered by 1993, being l cm in diameter. Plants from capillary mat sown seed were yet to flower, and were only ½ cm in diameter. Plants of C. coum 'Nymans' from compost-sown seeds also flowered in spring 1993 and again in late 1993, when plants raised from capillary mat sown seed had shown no sign of flower (tubers from both kinds of raising were then l cm in diameter). With C. libanoticum neither the plants raised from compost-sown seed nor those from capillary mat sown seed had flowered by late 1993, but those from compost were l cm in diameter and those from capillary mat only ½ cm.
So cyclamen sown and raised in compost are at a distinct advantage at first though now all capillary mat plants except C. purpurascens have virtually caught up.
Phil Cornish finds robust species germinate well in vermiculite and are easy to prick out. C. coum is less successful
For the past three years I have been sowing seed in small plastic bags of moist vermiculite. The bags are sealed and kept dark in a cool place at 13-15°C (55-60°F). Germination is usually evident in three to four weeks; the tiny tubers are pricked off into trays or plugs to grow on. The method saves times and space when so much is to be done at this time of year. The method works well for C. hederifolium and C. graecum. C. coum are not so keen on this treatment!
David Nutt finds pots in plastic boxes in a cool dark cupboard and seedling acclimatisation in a cool bedroom work well; capillary matting makes potting on difficult
Over the years I have used several methods of seed sowing with varying degrees of success. I have not conducted any recorded experiments but have tried to evolve a reliable and easy method which suits my circumstances, resolves problems and tries out new ideas.
My first attempt was with a packet of C. hederifolium seed from the RHS annual distribution. Having no experience, I sowed this as soon as it arrived early in the year in my standard cactus compost, basically a John Innes compost with a high percentage of added sand, in a small uncovered pan in the greenhouse. The germination was good; I had started on the road to growing species cyclamen and joined the Society.
This method did not prove so effective with other species, so having read the books I tried more equitable temperatures and covered the seed pans prior to germination with moderate success.
At this point the Journal published accounts of seed raising using damp capillary matting in plastic boxes in cool dark cupboards. I tried it. It produced good results with fresh seed. But the transfer of the seedlings from this environment proved difficult. The roots caught in the matting, the tiny plants were difficult to handle, and they resented the move into compost. Despite great care in potting and in adjusting the environment, losses proved to be unacceptably high.
My current method, which so far has worked quite well, is to sow into small square pots in my normal soil-based compost. The pots are watered, put into plastic boxes (ice-cream containers), lidded and placed in a cool, dark cupboard. As soon as germination is noticed the pots are transferred to another box, and gradually accustomed to the light and to a normal atmosphere on a north-facing window sill in an unheated bedroom. The plants stay in the pots until they are big enough to handle without undue care, maybe a year or even more. To be able to do this the seed must be well spaced when sown.
Norman Dart finds autumn best for matching the temperature needs of seeds sown in the dark.
Keeping careful temperature records, I noticed with fresh C. coum seed sown in early July that there was no germination while the temperature in my greenhouse stayed generally above 20°C (69°F). However, at the end of August after a week in which the temperature stayed consistently below that level, 11 out of 17 seeds germinated. The temperature was rather higher again during September and much of October. In late October and early November it fell well below that level, and by 5 November all the remaining seeds had germinated. On 23 September I sowed seed of C. coum 'Tilebarn Elizabeth', C. parviflorum, C. rohlfsianum and C. trochopteranthum. Nothing happened for the first few weeks, in which the daytime temperature was above 20°C (in the 7Os°F) on most days. After 20 September and more decidedly after 28 September the temperature fell to around 18°C (64°F) max. and 8°C (47°F) min. By 11 November, after a couple of weeks of these cooler conditions, most C. coum and C. rohlfsianum germinated, as did some C. trochopteranthum. However C. parviflorum did not respond.
Ann Harrison finds damp tissue a useful germination medium - but finds cyclamen seeds will put up with almost anything!
Last year I had my first ripe seed capsules, on C. hederifolium. As I was trying to pack up, ready to move house, seed trays were not a very good idea. I rescued two plastic tubs, with no lids. I put tissues in each one, dampened them, put the seeds in, and folded the damp tissue over the top. In desperation I then put the containers in plastic bags and criss-crossed elastic bands over them. They then sat on my window-sill for two to three weeks, endured the move, were dumped in a small, unheated greenhouse, and behold I then found that approximately two-thirds had germinated. I've now put them in compost and speak more kindly to them. At the same time I put some other seeds in a pot of gritty compost, cut a disc of cardboard which I put over the top, placed the whole lot in a plastic bag which I tied at the neck, and left it in the garden. I then forgot them. A friend fostered many of my potted plants while I moved, and eventually at the end of October brought them to me across the country. When I saw this plant pot, soggy, the top covered in green gunge, I couldn't even remember what was in it. My friend said she hoped it wasn't anything important as she'd dropped it. I opened it, and found a forest of cyclamen. I think every single seed must have germinated, thrived on neglect, and grown. I have since potted them on and they seem quite happy. They are of course C. hederifolium, and probably would have grown anywhere, but I was still delighted. I don't seem to be quite so successful with seed which I treat kindly.
The report of the Reading University germination trials gives a firm yardstick for future "best practice": 15°C (59°F), steady moisture and complete exclusion of light. Even so, all too many of us are bound to fall foul of the trap Dr Ross warns of - that failure to get all three factors right on the first attempt seems to trigger a deep-seated dormancy which may resist future attempts even if these attempts do correctly line up temperature, moisture and darkness. So the search for an elixir to override the dormancy will no doubt continue.
Pamela Dyer of South Australia is intrigued by the possibility that an
enzyme may be involved. She wonders whether some people's success with
pre-soaking seeds in a detergent solution may have depended on the presence in
the detergent of the protein-digesting enzyme trypsin.
Furthermore, she wonders whether ants may play a dual role in disseminating cyclamen seed. It is now well established that they spread and probably bury cyclamen seed, attracted by the "elaisome" or sticky substance coating it (in the dry sandstone country around Sydney nearly half of all plant species have elaisome on their seeds, ants playing a major role in their dissemination). Pamela Dyer wonders whether the ants also secrete an enzyme when they eat off the elaisome, which starts to digest whatever agent in the seed coat inhibits germination.
She has tried the effect of the enzyme cellulase on cyclamen germination with some success. (She obtained a cellulase solution by the unorthodox but perfectly effective expedient of soaking half a dozen snails in swirled water for ten minutes; members who can obtain pure laboratory cellulase may prefer that approach.) She soaked two-year-old seed of C. persicum in this solution overnight, then gave it several washings in tap water and rolled it in wet paper. As a control, she soaked other seed from the same batch in warm tap water, leaving it in the same water overnight. The seed treated with the cellulase solution gave very much quicker germination than the control: as one might say, snails for speedy seed.
The alternative approach is to let nature take its course. Many members of the Society swear by this approach. As Jeff Watts of Bedfordshire puts it, maybe people who have difficulty with germination are trying too hard and instead of mollycoddling their seeds should supply them with the bare essentials and leave the rest to nature. After all, he says, up on the mountainside there's nobody to wrap the seeds up on cold nights or protect them from the elements.
Mr Watts soaks distributed seeds in fairly warm water for 24 hours, then
plants them in 7.5 cm (3 in) pots which have been filled to within 1 cm (l/2 in)
of the rim with John Innes or Arthur Bowers compost and have before sowing been
stood in a tray of water until the top of the compost is well wet. (He finds the
pot material, clay or plastic, seems to make no difference.) His own seed is
sown within minutes of being removed from the capsule, without cleaning or
soaking, complete with their sticky coating of elaisome.
All pots are then left outdoors in a structure of shade netting, to protect them from neighbours' cats and dogs. If he remembers, in very heavy rainfall he puts a sheet of glass over the pots to stop the seeds and soil being washed away. After germination he adds a pinch of fine grit to the top of the pots to help secure the young seedlings.
This laisser-faire regime works well for him. Of the 1991 Cyclamen Society distribution, 13 out of 14 pots have germinated well; from the 1992 distribution he already has seven pots of healthy young seedlings. Among his own seeds, he has found even C. parviflorum germinates briskly when treated like this (but is then slower than most to make headway). He is interested to know whether other members share his experience that C. afticanum and C. graecum consistently germinate more quickly than C. hederifolium.