Colchicum autumnale – a Star of Early Autumn
Colchicum autumnale demonstrates how easy it is to make bulbs flower indoors. Though similar to crocus in appearance and often called ‘autumn crocus’, it belongs to a different family, Colchicaceae, whereas crocus is a member of the Iris family. Its roots sold in shops, though similar in appearance to bulbs, are not a true bulbs (made of fleshy scales), but corms (made of solid tissues). The name Colchicum derives from Colchis, an Ancient Greek name of a region on the eastern side of the Black Sea, in modern Georgia, an area where Colchicum grows wild. Colchis is one of the settings of the myth of the Argonauts, a group of warriors who travelled from Greece on a ship Argo in a quest to find the Golden Fleece. In Colchis their leader Jason was helped by Media, daughter of the king of Colchis, to win the Golden Fleece in a series of trials.
One of the most beautiful forms of this plant is Colchicum speciosum (‘beautiful’ Colchicum), a large-flowered variety, that produces several deep purple-rose flowers up to 8cm in length. It is sold in garden centres in late summer and early autumn, and is often bought as a curiosity – a flower that grows without soil or water. Indeed when the period of dormancy ends and the flowering time arrives (September – October) the corm flowers dry, without any care, on a window sill, a desk or a shelf in a garden centre. At this time Colchicum corms can be seen displayed in windows of flower shops for decoration and advertising. Such flowers are produced entirely due to nutrients stored in the corm and turn out a pale shade of pink or lilac, with long distorted stems and rather miserable looking. To see Colchicum in all its beauty one needs to choose a large firm bulb (and some can be half a pound or more in weight) and plant it in a pot with garden soil, home-made or shop-bought compost, or even just wet sand or fine bark chippings. In these conditions a good bulb will quickly produce several flowers. The flowers will be more intensely coloured and more robust if pots are positioned in bright light, for example, on a windowsill or in a conservatory. It is important, however, to do it early because flowering ends in October and can’t be delayed. Colchicum has an extremely short shelf life.
After flowering pots can be taken into the garden – Colchicum is hardy to -10 or -15C. In spring plants will produce leaves. They should be grown in soil rich in organic matter, kept most, but not waterlogged, and, if grown in pots, occasionally watered with an organic fertiliser. Leaves will die off in mid summer, and in autumn Colchicum will flower again.
Colchicum looks lovely in pots and in the garden, and with availability of different varieties, including white and double (Colchicum ‘Waterlily’), there is every incentive to grow this beautiful plant. Colchicum is often grown by children, but it should be remembered that fresh corms are highly poisonous. They contain colchicine that can cause strong irritation of skin, and should never be in contact with eyes. Colchicum is a valuable medicinal plant: its preparations were used in traditional medicine to treat gout and colchicine is still used for this purpose today.