Cyclamen hederifolium and C.coum are extremely tolerant to a wide range of soil conditions and positions and can grow well under trees and in similarly "difficult" places. C. hederifolium flowers in late Summer/early Autumn and C. coum in the early part of the year, providing welcome colour at that time of the year. Their leaves are attractive in their own right and provide valuable ground cover. The plants naturalise well and once established can survive for many years through the toughest weather. They can also be grown very satisfactorily under glass producing a mass of flowers. They are therefore extremely versatile and rewarding for both the amateur and enthusiast.
2. Recommended potting period.
The tubers will be dug up in late June and July when they die back for the summer and before the main growth starts (though some tubers may show signs of growth). It is advisable to pot them up as soon as possible after receipt. Alternatively, they may be sold as bare tubers, but this can, on occasion, prompt them into dormancy and they then take a little longer to establish themselves.
Cyclamen are tolerant of a wide range of potting composts, the major requirement being that it is free-draining. A mix of equal parts peat, sterilised loam and grit (5mm down) has proved very satisfactory, adding about 4oz bonemeal to every 8 gallons or so of this mix. Proprietary soil-less composts can be used but it is advisable to mix grit, coarse sand or perlite with it to improve drainage and to add a little in the way of nutrients.
4. Growing regime
The tubers should be potted in the mix above on receipt with the roots distributed in the medium and the top of the tuber just exposed. The pot should be topped off with a layer of 4mm or so grit taking it right to the rim of the pot. Water the pots in well with a mix of Rovral or other proprietary chemical. Subsequent watering is then best done from the bottom keeping the compost damp but not wet. Assuming that the tubers have been potted into 9cm plastic pots (see below), watering is best achieved by standing the pots on shallow beds of grit-sand and allowing the water to stand for an hour about half an inch up the pot. Drain after an hour.
Note that cyclamen can be grown successfully watering from the top; perhaps what is most important is to decide which route is to be taken and then to stick with it.Cyclamen need ample ventilation but both hederifolium and coum are able to withstand considerable cold. It's perfectly satisfactory to keep the pots outside, though the plants may present better for sale if they're kept under cover. It is not necessary to provide heat in the winter unless extremely severe frosts threaten.
5. Pest and disease control
By and large, cyclamen are pretty trouble-free. The most serious pest is vine weevil and if the characteristic bites nibbled out of the leaves are spotted, immediate steps should be taken to get rid of the pest (using SusCon Green or Nemasys H). Infected plants should be eliminated from the stock. Good housekeeping in removing dead leaves in and around the plants should help to prevent infestations.
Larvae of sciarid flies can also be a problem and can be controlled with gamma-HCH or malathion. Aphids may occasionally visit the plants but cause relatively little damage and can be controlled with any of a range of sprays.
Slugs and snails should be controlled using slug bait and removing any debris around the plants.
Squirrels and mice may dig up the tubers or nibble at seed pods - mouse killer and wire mesh doors can keep any harm to a minimum.
Botrytis is the most common disease affecting cyclamen - good ventilation and hygiene is crucial. Spraying with Rovral, Captan, Zineb etc will control the disease. Any dead leaves must be removed from the plants as a matter of routine.
6. Ideal pot size
C. hederifolium tubers will be an inch or more in diameter, C. coum three-quarters of an inch or more and should be potted into 75 to 90mm pots. Cyclamen often flower better if under-potted so even the larger tubers supplied should go into this size of pot or one which just takes the tuber.