Generally referred to as being the, to which they are not even botanically related, though they may resemble the autumn-flowering crocuses. They are also confused with the Saffron , sativus, for they are often called the Meadow Saffrons. They do, however, bloom from early September and right through October, most of the species being at their best before the true Saffron crocus, C. sativus, comes into bloom and followed by C. nudiflorus and C. speciosus.
Perhaps it is their production of rather rank foliage during spring and early summer that has always told against these plants, for this gives the rockery and lawn a most untidy appearance. The true autumn-flowering crocus are blessed with the dainty grass-like foliage of the spring-flowering species and so may have suffered in confusion with the Colchicums, when the question ‘autumn crocus’ has arisen.
But for all that, the Colchicums are delightful plants and they should be planted in the shrubbery, dell, on a grassy bank or by a stream and should be planted in quantity. There they will produce their attractive long cup-likewhen the days are rapidly shortening and will be a delight throughout autumn. I once planted several species along a low wall with several mossy saxifrages for a soil covering and the effect was delightful. Or try planting the yellow Colchicum lutea amongst some plants of Romeo. This is the only early spring-flowering Colchicum I know and the only yellow variety. But mossy saxifrages will be of the greatest value not only as a background to accentuate the colour of the , but also to act in saving the plants from being splashed by heavy rain.
Although the Colchicums seem to do well in almost any well-drained soil, even of poor quality, for they will flourish in a shrubbery of a town garden, they thrive best in one containing plentiful supplies ofmould. Where this is not present, fork into the soil a quantity of peat, spent hops or any available humus and do not forget to add some brick rubble. Coarse sand should be liberally sprinkled round the bulbs as they are set 2-3 in. below soil-level.
July seems to be the best time for planting for the foliage dies down in late spring and the bulbs will be completely fortified and ready for lifting and replanting by midsummer. If left too long, they will commence to throw up their flower buds which may easily be damaged during replanting. In any case, they should be established in their new quarters by the time they produce their flowers in September. Use the shrubbery or border rather than a rockery or lawn for their planting, for not only does the rather coarse foliage appear in the early new year, but it turns an unattractive brown colour in spring whilst dying back. As the foliage must be allowed to die back naturally to fortify the bulbs nothing can be done about its unsightliness. The Colchicums are not very suitable for indoor culture – in any case, there are many lovely autumn- and winter-flowering crocus species that will give a wide flowering range.
- Colchicum autumnale. This is the exception to planting the Colchicum in the rockery, for its habit is so neat that its foliage should not prove unsightly. The small lavender blooms are enjoyed throughout September. The white form (album) is also most attractive.
- C. autumnale plenum. This is a most interesting double form for November flowering. The colour is deep rose and it is able to withstand adverse weather conditions. There is also a double white form but unfortunately both produce rank foliage.
- C. Bornmidleri. From the far Mediterranean area. This species produces its large purple and white flowers during September.
- C. bAantinum. In bloom throughout September and October, the lavender-rose flowers being most delightful.
- C. letens. Flowering from December until March, this is the only known yellow form of Colchicum. It reached England from Afghanistan about 1875 and is really a species quite apart from the other Colchicums It produces its flowers from purple-tined tubes which are a constant attraction to winter slugs, so it should be given the protection of a cool where it will bloom undisturbed throughout the winter.
- C. Parkinsoni. This is a lovely October-flowering species, bearing unique white flowers chequered with purple. It is of strong constitution.
- C. speciosum. From Persia and as Farrar in The English Rock Garden says: ‘One of the most beautiful plants in the world.’ The Century book of Gardening adds to this by describing it as ‘a noble flower’. Flowering late August and into November, when it produces its brilliant carmine-purple flowers in great profusion, it should be planted with abandon in every shrubbery and border. And plant with it the expensive but pure white form for an arresting .
Slugs are the chief source of worry with Colchicums and particularly do they attack the succulent tubes as they emerge from the ground. Slug bait may be placed in small piles at short distances away from the plants as soon as they can be seen above the ground, but I find that if a covering of weathered boiler ashes is placed over the area where the bulbs are planted during July, this will not only be a satisfactory deterrent against slug attack but will also be added protection for the bulbs during winter.