Some like it cool

Anna Pavord asks the experts how to keep her cyclamens happy

As a convicted murderer of indoor cyclamen, it is perhaps rather shameless of me to be writing about them. "Oh, I love them to death," said a friend admiringly, as we checked out the newest delivery of cyclamen in our local garden centre. In my case, the phrase was hideously apt.

The kind of cyclamen that are sold as house plants come on tap just as the outdoor ones are finishing their display. Treated properly, they will continue to flower well into the New Year. But leaving the greenhouse where they have been cossetted since March is a great shock to the cyclamen's system. Under the care of a commercial grower, all its whims have been gratified. The plants have been well fed, doctored against botrytis, kept cool and well aired. Then suddenly the lulling routine comes to an end. There is no more capillary matting, no more temperature control, none of those little attentions to which a potted plant can so easily get accustomed. Cyclamen mind that and are not afraid of showing it.

I went this week to look at the extensive trials of indoor cyclamen organised at their Oxfordshire headquarters by Colegrave Seeds, who supply seed and mini plug plants to many of this country's commercial growers. "What are the secrets of success?" I asked. The answer seemed to be that to keep your cyclamen happy, you have to come close to hypothermia yourself.

Cyclamen hate central heating. The room temperature should be a steady 15-16C, or even cooler. The pots should stand in a bright, airy place, as far away as possible from radiators or fires. But though cyclamen like it cool, they do not like draughts, nor sudden fluctuations in temperature.

Plants should be watered sparingly with tepid water and the compost allowed to dry out a little between one drink and the next. The usual advice is to water from the bottom rather than the top. That is fine, said Colegrave's experts, as long as you don't leave the pot standing too long in water. If you do, the compost at the bottom of the pot will get saturated and the cyclamen's roots will rot.

When leaves or flowers die, pull them cleanly away from the tuber. Check that there are no broken bits of stem still lingering there for they will be magnets for grey mould (botrytis). The plants will have been fed regularly before you buy them with a fertiliser rich in potassium. Continue to feed with a balanced liquid fertiliser. Although cyclamen grow in pots which seem impossibly small for the amount of growth they produce, do not be tempted to pot plants on. Root disturbance is the last thing a cyclamen needs when it has more than 50 leaves, nine fully opened flowers and 27 waiting buds to support.

The quotas come from a plant in front of me at the moment, one of the monsters of the genre with a wide skirt of fleshy leaves, attractive but not as brightly marbled as, say, Cyclamen neapolitanum. The flowers are brilliant magenta. It is one of my favourite cyclamen colours but to judge from the trials, breeders are more interested in the salmon and scarlet shades.

Scarlet is one of the trickiest colours, said Colegrave's marketing manager, Alan Miles. Plants of this colour were not generally as vigorous nor were they so generous with their flowers. But the breeders are persevering with the strain because they believe a bright red cyclamen is what we want at Christmas. By this stratagem, cyclamen may win back some of the ground they have lost to poinsettias over the last couple of years.

In breeding for size, growers have lost the sweet delicate scent that is a feature of the wild Cyclamen persicum, the species from which all the florists' cyclamen have been developed. Recent breeding has reintroduced the scent in a smaller, much more delicate group of florists' cyclamen (the Colegrave strain is the Miracle series, all F1 hybrids). In between the two is an intermediate group, with some of the characteristics of both. The scent in this type is not so pronounced, but the plants are compact and have more flowers out at the same time than the specimens with the largest flowers. That means of course, that they do not flower over such a long period.

In the wild, C persicum grows in scrubby, rocky places in southern Greece and Turkey, Cyprus, Jordan and the Lebanon. The petal of a good wild plant would be about 30mm long. The petals of the brilliant flower in front of me are exactly twice that. A hundred years of breeding has produced the doubling, but some elegance has been lost along the way. The wild flower has the swept back petals, the general look of a small animal caught in the teeth of a gale, that gives all wild cyclamen enormous charm.

The wild species is a very variable creature, producing blooms in white and various shades of pink, usually with a rim of darker magenta round the mouth of the flower. This variability has been exploited by breeders to extend the colour range and select flowers with particular characteristics such as frilly petals, or foliage with good variegation.

Then, having produced a wide range of plants with different colours and characteristics, breeders want to stop the clock, and fix a particular set of characteristics in a particular strain, as with Sierra, Colegrave's F1 hybrid series of large-flowered cyclamen. Growers fighting to meet tight specifications need to know exactly how their plants are going to behave.

But I rather enjoyed their occasional insubordination. In a whole set of white cyclamen you would suddenly come across one that had decided to embellish a petal, and colour it one half white, one half pink, with a perfect straight line between the two. Hooray, I said under my breath, when I saw plants like this, refusing to bend to the breeders' lash.

The most splendidly diverse plants, miniatures, were those grown from the old Dresden seed strain. Their foliage was much more interesting than that of any other cyclamen I saw. There was one Dresden plant there, which had finely sculpted, swept-back flowers, white with a magenta rim round the mouth and leaves netted all over with silver, that would immediately have got my first prize in the trials. If any grower is offering for sale cyclamen grown from this seed, please get in touch.