This section is from the book "The Gardener V3", 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.
Hybrids of Gandavensis must be classed amongst the very foremost of autumn flowers, and we ought not to forget that we are indebted for nearly all of those beautiful varieties to our neighbours across the Channel. Notwithstanding the disturbance in France, another batch of new varieties has been harvested in good condition, and will be sent out yet if the state of affairs permit. M. Eugene Verdier Fils aine catalogues twenty new varieties for 1870-71. The Gladiolus is indispensable in the autumn flower-garden; it is the most effective object on the exhibition table; and the plants are useful and effective ornaments in the greenhouse and conservatory. They can be placed in positions where the spikes are seen amongst the green leaves of other plants not in flower, or amongst ferns. This plant is also well adapted for cuttings to place in vases, where the flower-spikes will continue to develop themselves; and some of the varieties will be more beautiful than if allowed to remain on the plant.
I will treat first of the culture of Gladiolus in beds out of doors. It is best to plant them in beds, placing the bulbs 1 foot apart each way, four rows in each bed. The ground will thus be laid out in 4-feet beds, with 18-inch alleys. A light sandy loam is the most suitable for them, and for such soil cow manure is the best. A stiff loam is not suitable for them, but it can be made so by using stable manure or rotted hotbed or stable manure and leaves, with the addition of leaf-mould, sand, or some loose material. As to position, it ought to be sheltered, especially from the west and north: there are generally furious gales from the west about the first week in September, and at this time the beds are in full beauty. The preparation of the ground is most important. This ought to be attended to early in the autumn, before the ground is drenched with rain. It should be trenched not less than 2 feet deep, working in plenty of manure, but none of it ought to be nearer the surface than 9 inches, as the bulbs have a strong aversion to close contact with manure of any sort. During winter and early spring it should be lightly forked over when the surface is dry.
It cannot be forked over too often, but do not touch it in wet weather or just after rains.
The Gladiolus lists are generally issued with the seed catalogues in December, and the bulbs should be ordered as soon after as convenient. Most cultivators agree that the small bulbs throw up the best spikes; but I leave the nurserymen to send out what size they like, only they must send them sound and healthy. A large bulb will throw up two or three spikes, and your stock is increased for the next season; and in new sorts this is important. I will give a list of the best sorts at the end of this article. As soon as the roots are received, place them in a dry airy place, free from frost, until it is time to plant them out. For succession, a planting should be made every two or three weeks from the 1st of March to the end of May. The bulbs should be planted about 3 inches deep, with a little sand under and over them. When the plants are about a foot high, the sticks should be put to them: they are very easily injured by the wind, and the roots will not be injured so much if the plants are secured to the sticks at this early stage of their growth. Waterings and mulching the beds with manure ought to be resorted to as soon as dry weather sets in. The ground being highly manured, there is some danger of over-watering, therefore great caution is necessary here.
A few years ago I saw some large beds containing hundreds of the best French varieties in the most unhealthy condition. The soil in which they were planted was somewhat heavy, but not unsuitable. The beds had not been mulched, and I felt no doubt, on examining the soil, that over-watering was the cause of failure. If the leaves cannot be kept of a healthy dark green colour, there will be no very good spikes. As the flowers continue to develop themselves they ought to be watched for a small green maggot, which will be found devouring the yet undeveloped flowers. The best time to dig up the roots is about the end of October, cutting them over at the same time, and laying them out in a dry airy place to dry before wrapping them up in paper, in order that they may be stored in boxes until the spring. One peculiarity of the Gladiolus is the manner in which the plants die off suddenly when in apparently luxuriant health, and it very often happens at the time when you are expecting to be repaid for a whole season's care and anxiety. The first signs of anything being wrong is the spike drooping in the sun. On examining the roots, the young fibres will be found dead or dying. Very often I have found manure in close contact with the bulbs.
Blanks will be made in the beds from this cause, and also from bulbs which, although to all appearance healthy when planted, throw up only a few sickly leaves, and ultimately perish. I grow a reserve in pots to meet such accidents. Pot-culture may be disposed of in a few words. A good compost for them consists of three-parts sandy loam, one of leaf-mould, one of rotted manure, and one of sand. I use 5 and 6 inch pots for the first potting, shifting into 7 and 8 inch as soon as the plants are 6 inches high. Plunge the pots in a cold frame, covering the pots over to secure them from frost. I use cocoa-nut fibre refuse for this purpose, and I know of nothing better for plunging all sorts of pots in. The pots must be examined occasionally, and as soon as the plants are seen above the surface of the mould the material covering the pots should be removed, and as much air as possible admitted to the frame. Some time in May the plants are removed to a sheltered position out of doors, until the first flowers show signs of opening.
They may be removed to the greenhouse, or they can be retarded by placing them behind a north wall.
The Gladiolus may be propagated by taking care of the spawn or very small bulblets which cluster in greater or less numbers round the base of the large bulbs: some of the varieties will only give three or four of such small bulbs, others a hundred or two. A well-known cultivator told me the other day that he counted 200 from one plant of Orphee, one of the best new ones of the present season. When they are found in such large quantities, the best way is to draw drills and sow them out of doors. The more scarce varieties should be potted - a dozen bulblets planted in a 6-inch pot. The bulbs obtained from the spawn will each throw up a fine spike the following year.
The best new varieties of the autumns of 1868-69 are - Armide, Delicatissima, Homere, Horace, Madame Desportes, Madame Dom-brain, Marie Stuart, Michel-Ange, Monsieur Legouve, Orphee, Robert Fortune, Rosa Bonheur, Schiller, Virgile. These were all raised by Souchet. Julia, sent out by Kelway, is a first-class flower. The best of the older varieties are - Adolphe Brogniart, Etendard, Eugene Scribe, Fulton, Galilee, Imperatrice Eugenie, James Veitch, La Favorite, Le Titien, Madame Furtado, Marechal Vaillant, Marie Dumortier, Meyerbeer, Moliere, Newton, Prince of Wales, Princess of Wales, Princess Mary of Cambridge, Princess Clotilde, Reine Victoria, Rossini, Shakespere, Ulysse. The above named is a select list, and I have grown and flowered all of them except La Favorite, but which I have seen very fine in Mr Kelway's stands. It is rather tender. I have omitted other fine sorts which are delicate in constitution, or at least do not succeed with me. J. D.