This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
There are many species of gladiolus, but not one has yet attained sufficient importance to become a market plant. Excluding the European byzantinus and communis, they are mostly natives of Southern Africa. From the florist's point of view the hybrid Gladioli, such, as brenchleyensis, Colvillei, Childsi, gandavensis (fig. 203), Lemoinei (fig. 204), nanceianus (fig. 205), and nanus, are the most valuable; and a great trade is done in the corms or solid bulbs in spring and autumn, and in the flowers in spring and late summer and autumn. For market work G. Colvillei, rose and white, and its variety "The Bride", with pure white flowers, sell well in spring, the spikes being largely used by florists for decorations. The bulbs are placed in pots or boxes in autumn, and covered over with a few inches of soil or ashes until wanted for gentle forcing. This takes place from Christmas onwards. The bulbs are also planted 3 or 4 in. apart in cold frames and protected with the lights to yield a succession. The same treatment is given the forms of G. nanus, which produces long graceful sprays of rose, pink, and blotched flowers with great freedom. These forms have been evolved from such species as trimaculatus, tristis, blandus, cardinalis, etc, kinds which are to be found in botanical collections. The more showy kinds of Gladiolus, like brenchleyensis, Childsi, Lemoinei, nanceianus, and gandavensis are planted in March or April in rich and well-prepared soil 6-8 in. apart in rows, the corms being covered witli 3 or 4 in. of soil. The flower spikes appear in August and September, and find a good sale amongst florists. After the flowering is over the corms should be lifted, cleaned, and stored away in frostproof, dry, and airy cellars or lofts. The offsets and spawn should be detached from the larger corms and kept separate, planting them out in spring in places by themselves until they reach the flowering stage.
Fig. 203. - Gladiolus Gandavensis.
Fig. 204. - Gladiolus Lemoinei.
Fig. 205. - Gladiolus nanceianus.