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.
Under the same circumstances, these will require a good watering this month, - in the first place to finish the spikes, which are well advanced during this month, and also to plump up the corms for another season's planting. I like to grow these also on deeply trenched, rich soil, and though the corms are not planted till towards the end of April, they make rapid progress so treated. Indeed, a florist-who saw them in the beginning of June, remarked that they must have been well forward in pots before being planted out! Gladioli are much like potatoes : they like the soil and the general temperature warm before being planted, dryish warm weather till the corms begin to plump up, then a good soaking and a fine warm air to finish them off with.