Jour. Roy Hort. Soc. 1: 178-180 (1846)

XXIV.—On the Treatment of the Genus Amaryllis for Autumnal Blooming.
By Mr. John Spencer, C.M.H.S., gardener to the Marquess of Lansdowne, F.H.S., at Bowood.
(Communicated March 16, 1846.)

THE great scarcity of flowers during the months of October, November, and the early part of December, for decorating the conservatory and drawing-room, induced me to try the experiment of so far altering the habit of some of the varieties of the genus Amaryllis, as to enable me to depend on their blooming in those months as strongly and regularly as they usually do in the spring. The success that has attended my practice, and the great acquisition they are at that time for the above purposes, have induced me to lay my method before the council of the Horticultural Society.

Before I explain my own mode of culture, I beg to quote the opinion of the late President of the society on the growth of bulbous plants in general, as it has furnished me with an admirable groundwork for prosecuting the cultivation of this tribe of plants.* "Bulbous roots increase in size, and proceed in acquiring powers to produce blossoms only during the periods in which they have leaves, and in which such leaves are exposed to light; and these organs always operate most efficiently when they are young, and have just attained their full growth."

Bearing these important facts in mind, we will suppose a moderate collection is already in hand, and the object to be attained is to induce the bulbs to bloom in the autumn months. In the first place they should be potted in December, using pots in proportion to the size of the bulbs. The soil I have found best suited for their growth is composed of two-thirds light turfy loam, and one-third of half rotten leaves and coarse river sand, draining the pots well, and using the compost in as rough a state as possible. If additional stimulus is required, it may be supplied, when the leaves are fully formed, in the shape of manure-water every second or third watering. In potting them, observe to keep two-thirds of the bulb above the earth in the pot: they should now be plunged in a pit or frame near the glass, and where there is a moderate bottom heat to encourage the bulbs to root freely before they commence growing by the leaf; and to accomplish this, the bottom heat should be considerably in advance of the top.

When it is found that the roots have made considerable progress towards filling the pots, they should be removed to a light house, and be placed as near the glass as circumstances will admit. The temperature of this house should be kept between 60 and 75 degrees. The increase of both light and heat will cause the bulbs to grow rapidly, and great care should be taken not to injure the foliage; if any blooms appear they must be removed, and water supplied when requisite; by this treatment the plants will in a short time possess a strong and healthy foliage, at which time manure-water may safely be applied with the best effects. Whenever the appearance of the leaves indicates suspension of growth, water should gradually be withheld; but they must still be exposed to the utmost amount of light and heat, until the leaves become of a partially brown or yellow colour, when they may be removed to a dry cool place until wanted for blooming. By the above treatment they will generally be in a perfectly ripened state by the end of April or early in May.

I do not agree with those who advise that, during the period of the plants' rest, they may be shaken completely out of their pots, for I find they bloom much stronger by being allowed to remain in the pots in which they grew. It will be seen that the roots, if taken proper care of, keep fresh and vigorous during their rest, and shaking them out would greatly weaken their after-flowering. It is not material where they are kept during their repose, provided they are kept dry.

Towards the end of August preparations may be made by commencing with all or part of the stock: the pots should be well soaked with water, and then plunged in a mild bottom heat in any pit or frame that may be at work. When the flower stems have advanced 6 or 7 inches in height they may be removed to a stove to open their flowers, and afterwards placed either as ornaments for the conservatory or turned out into vases or ornamental pots for decorating the drawing-room—where the nobleness of their flowers, and elegance of habit, make them suitable decorations. By the above management I have found those varieties enumerated below bloom quite as strong as they usually do in the spring: Johnsoni, Reginae, Vittata, Reticulata, and their allies, frequently have 3 or 4 spikes of bloom, and attain the height of from 3 to 5 feet.

Immediately after they have done blooming they should be partially shaken out, disturbing the roots as little as possible, and repotted as before advised; placing them in a bottom heat until the roots have taken hold of the soil. And then is to be pursued a similar course of treatment, as before recommended.

In conclusion I beg to add, that few flowers will better repay the little extra trouble their successful cultivation requires than the Amaryllis, and that none is susceptible of greater improvement: their cultivation appears to have retrograded of late years, this genus having, as I think unjustly, been thrown into the shade by more favoured races. Still I hope some spirited cultivator will again bring them into public estimation, and place them in company with other more esteemed species. List of varieties grown to bloom in the autumn: