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.
The Hyacinth is a native of the Levant, an old and valued inmate of British gardens, and was cultivated in the time of Gerrard at the end of the sixteenth century. Gerrard mentions the single and double blue, the purple and the white varieties existing at that time; and there is every reason to conclude that the Dutch possessed many improved kinds. Parkinson, some thirty years after, enumerates eight varieties, and so on. We still find the Hyacinths improving in quality, increasing in numbers and value. Only single kinds were first cultivated. The first named double we find on record was named "Mary," raised in the commencement of the last century by one Peter Voerhelm. Mention is also made of another by the same raiser called the King of Great Britain - which brought £100 sterling. Haarlem has been long famous for the cultivation of this root, as well as successful in raising countless new varieties. So enthusiastic were some of the growers in pursuit of double sorts that as much as £200 has been given for a single root.
The Hyacinth may be increased either by means of seed or by its off-set bulbs. It is useless to discuss its culture from seed here, so we shall confine our remarks to the method of rearing young bulbs to maturity. So, at the outset, we shall suppose that the parent plants which are to supply the off-sets are in pots. Those plants have just done flowering, the flower-stems should be cut out and the plants moderately supplied with water until indications of ripeness appear by the foliage assuming a yellow tinge, when the bulbs ought to be shaken out of the soil and put on boards to dry in the sun; after which the withered foliage should be cut clean away from the crown of the bulb, and have the young bulbs separted from the old; then prepare suitable bed in which to plant the young. To do this properly a warm dry corner should be fixed on; then have as much leaf-mould and sand wheeled on to it as will raise the bed, when trenched, 5 or 6 inches above the general ground-level. In addition add a fair proportion of rotten cow-manure, and proceed with the trenching.
The bed being in readiness, plant the bulbs in rows, inserting them 2 inches below the surface and 15 inches between the rows; this will admit of rows of some slender annual being sown between the bulbs, which will enliven the spot without hurt to the bulbs. Any time in October will do to plant the off-sets, but the ground should be rather dry. Preserving the bed from weeds, and cutting out the flower-stems before flowers get formed, is all the labour entailed in the succeeding two years; but in the autumn of the third year the bulbs will generally be fit to plant in beds to flower the following spring.
As soon as the summer flowers have been removed from the beds have them deeply dug and well manured for the reception of the Hyacinths. This should take place in October, and besides digging the beds they ought to be neatly edged if on grass. Proceed next to plant after this plan: - First line the bed regularly into divisions of 9 inches between rows, and dibble holes on the lines 8 inches apart, then plant the roots into the holes so that they are 3 inches below the surface. When the bed has become completed it is advisable to plant close to the margin a line of Crocus, inserting them 3 inches apart. The Crocus will be the first to make a feature in the spring, and will continue to impart a lively effect to the bed up to the period when the Hyacinths bloom.
When the flower-stems reach a height which endangers them being broken by rain or wind, they should be supported by means of short stakes. These should reach no further than the base of the flower-spike. And when the flowers have withered lose no time in removing the flower-stems, but preserve the foliage to the last moment you can allow them to occupy the bed, which will in a great measure favour the ripening of the roots.
Those intended for early forcing should be planted as soon as they can be obtained from the nurseryman, and instead of plunging them in the usual manner out of doors, have them packed beneath a stage in a rather close greenhouse or frame, sifting some coal-ashes over them to protect the bulb from drying. Give no water for the succeeding ten days, then enough to wet the entire ball. Observe that all the bulbs are planted firmly into the soil, and sufficiently deep to prevent them being started out of the soil when the roots protrude from the bulb in a body, as they naturally do. This is prevented by examining them daily, and pressing firmly down those that show a disposition to start from their bed. The soil to be preferred for early forcing ought to be light, rich, and porous, while the pots ought to be not larger than 5 inches in diameter, well drained, and the soil made rather firm. Allow the plants to advance in growth, enough to fill the balls with roots before putting them into the forcing-house; and should the young crowns be in any degree blanched, by being covered or shaded, shade them partially the succeeding week after being put in to force.
When forcing is commenced, the temperature ought not to be above 50° at night, with a slight rise of heat in the day-time, allowing a few degrees more weekly as the plants advance in growth, making GO0 the maximum, with moderate ventilation. Water abundantly both by means of the syringe over head and supplies at the root, never once permitting the soil to indicate dryness in the least. Place the plants as close to the glass as available, and turn them round now and then, to prevent the stems getting twisted, which will also materially assist the uniform expansion and colouring of the pips. When their flower-stems are somewhat advanced, secure them by means of inserting stout wires, that have been previously sharpened at the points, into the centre of the bulbs. This insures handsomer plants than when clumsy stakes are stuck in outside the bulbs, and is harmless to the plants also. Plants that are intended for successional blooming need not be put under glass, but plunged in the usual way out of doors, only putting them under glass some time prior to their being wanted to take the place of the first lot.