This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
Everywhere we now hear of the deterioration of this beautiful autumn flower, and of unsuccessful attempts to get it to grow year after year without buying a fresh stock of bulbs. This state of things is most unfortunate, as bought bulbs cannot in every case be induced to grow. This spring, for instance, some fourteen out of fifty bulbs I purchased are still lying as they were planted, without making a sign of life.
Though I have before told in the 'Gardener' of the treatment I find successful with the Gladiolus, I think the subject will bear repetition. My plan is to wait till warm weather - about the end of April - before planting, and to plant in highly cultivated ground : it is impossible to cultivate too highly. Then, in a season like the present, it is an absolute necessity that the young bulbs should be artificially ripened, as they will not ripen if left in the ground. Some of the earlier sorts, as Didon and Shakespeare, may, but the great majority will not. The only plan, therefore, is to lift the plants as entire as possible, securing a ball of soil round the roots, and placing them in vineries or plant-houses to finish : those which have not flowered at this date may be lifted, the ball of soil crammed into a pot, and the flowers allowed to open in greenhouses or conservatories. It has been chronicled that lifting Gladiolus and ripening them under glass is of no use : I do not suppose it is when the plants are merely pulled up and laid in bunches on the borders. Such treatment may benefit ripened bulbs, but not those which are in full growth.
I am confident, from my own experience, that any one having late Gladiolus will, by lifting them as above directed and placing them in an airy structure until ripened, and the succeeding season letting the sun have some effect before planting, find that it is not altogether such an uncertain flower as it has got the character of. R. P. Brotherston.