Plant, Grow, and Care for Hardy Cyclamen
Cyclamen hederifolium grows in the light shade and forest debris of the woodland. During the fall and winter period it needs moisture while flowering and growing leaves, this is their growing season. In the dryness of summer the plant goes dormant needing little or no water. The ideal is cool(40-60°) wet winters and hot dry summers(70-90°).
Soil and Temperature Zone
Cyclamen hederifolium is a hardy perennial, robust, tough and durable. It will grow under a large range of conditions from bright sun to deep dry shade but prefers the light shade. I would avoid areas where it would bake in the hot sun all summer long. It will grow in any soil, sand or clay but like most plants it does best in a loose well drained soil with lots of compost and a covering of mulch. I have many cyclamen that seem to like growing in dense clay, gravel walkways, and among the impenetrable roots at the base of trees. Soggy or very wet soils should be avoided as it will cause them to rot.
It has been stated in many places that C. hederifolium is hardy in zones 5 through 9. In zones 8 and 9 there won't be any danger from winter cold. In zones 7 and below there might be damage from long periods of snow cover. Snow will protect them from deadly freezes but remaining under a blanket of snow for more than several weeks will cause them to lose some leaves. After three or more months under the snow I wouldn't count on them to bloom the next fall. In zone 5 and 6 it will take some diligent searching to find a micro-climate that will allow them to grow year after year. In the colder zones I suggest you seek information on growing hardy cyclamen from garden clubs, rock garden societies, or other gardeners in your area. Such information can be valuable in growing hardy cyclamen successfully.
The Cyclamen Society reports on the hardiness of C. hederifolium: " It easily survives low temperatures, and grows quite happily in a zone 4 area of New York State, USA where temperatures have reached as low as -28 ° C, -19 ° F)." I believe hardy cyclamen can survive a brief overnight drop in temperatures well below zero but cannot endure weeks or even days at such temperatures. If anyone in zone 4 has had success in growing C. hederifolium I would like to hear from them.
For those in the colder agricultural zones you can still grow hardy cyclamen quite well in pots. The corms can be dug up before winter sets in and potted or grow them in pots the year around. The pots can be placed in a cool greenhouse or cold frame through the winter. I keep some potted cyclamen in the garage under artificial light. An excellent map to find your growing zone is the USDA Plant Hardiness Zone Map.
Landscape with Hardy Cyclamen
Even though hardy cyclamen looks dainty and small it can have a large impact throughout your garden. Hardy cyclamen are a great addition to the rock garden and alpine garden. Place individual corms among rocks and in gravel. Since they are small it is nice to plant some where you can observe them up close, either in pots or near walks and entryways.
At further distances as an under-plant of large shrubs, like rhododendrons, hardy cyclamen add a whole new layer of color to the landscape. Planted in a bed of their own a colony will form a lovely low ground cover.
Hardy cyclamen are one of the few flowering plants that will flourish in the dry shade one of the most challenging spots in any garden. They thrive under trees and large shrubs, both evergreen or deciduous, where their flowering color and ivy-like foliage can soften and add interest to those bare areas.
If you are just starting to grow hardy cyclamen in your landscape treat it like a woodland flower. Plant it where it has a deep leaf mulch, summer shade and some protection from harsh winter conditions. Hardy cyclamen do well, and look natural, at the base of trees, large evergreen shrubs, rockeries, and open shady areas. Once they get established try growing them in more challenging areas of the landscape.
Care for Hardy Cyclamen
Hardy cyclamen is one of the easiest plants to care for in the garden. When dormant during the summer the leaves will die down, fall off and dry up. They practically disappear so beware when digging near their bed! With so little remaining it isn't necessary to clean up. Raking should be avoided as it could cause damage to the shallow corm.
The summer dormant period of hardy cyclamen is a great time to move them. If starting with seed or small corms I suggest planting them close together so they make the biggest impact when flowering. As they grow you can dig them up every couple years and expand their growing space or move some to a new area. The plants should be kept moderately moist during the growing season, September to June. In summer no water is needed but watering will not hurt them. I have found that a little moisture during the summer keeps the roots intact and growing. Fertilizing isn't necessary. When the leaves die down and dormancy begins it is helpful to cover with an inch or two of leaf mould, compost or mulch. In colder growing zones a heavier mulch, up to six inches or more, might increase chances of survival. The stems will easily find their way through.
Hardy Cyclamen has few Pests
Pests and disease are rare. I have found slugs and snails may take a bite but generally leave them alone. Squirrels may dig them up and try a taste but don't care for them. The only pest I know of is the grub of the black vine weevil. The adults avoid the foliage so there isn't any telltale notches in the leaves to alert you to their presence. They are usually only a problem if you are planting them in an area that is infested with them. The grubs bore into the tuber and cause them damage. The best remedy is an application of beneficial nematodes, Nemasys H, to the soil in fall and spring. These pests are abundant here in western Oregon and none have been a problem for me.