'At Summer's call the Lily is alight.'
THOUGH the Lily is a hardy plant there are gardens in which it can only thrive when represented by the ordinary members of its family; some of the hardiest but rarer individuals need special soil and well-selected situations, and it is because these have failed so often, through being misunderstood, that they are seldom to be met with except upon large estates in the care of clever men. Thus, while it is correct to counsel garden-owners to grow them out of doors (as I have done in Chapter VII (Hardy Lilies, The Galtonia And Hardy Gladioli)), it is equally correct to advocate their culture in glasshouses together with certain other species that have long been noted as fine pot subjects.
The Lily of all Lilies that is beloved for forcing into early bloom is Lilium Harrisii, which is becoming very scarce.
Pot each bulb in a six-inch pot, or three in a tub, covering in no more than half an inch, but seeing that they are set firmly without being over-hardened. The right compost consists of an equal mixture of loam, leaf-mould, peat, sand, and dry decayed manure, preferably cow-manure pulled into small pieces. Place several nuggets of charcoal in the compost for each pot. Use perfectly washed and dried pots, whether new or second-hand, and it is wise to bake the leaf-mould before use, or even to sterilize the whole compost by pouring absolutely boiling water over every atom, then spreading it out to dry where no insects can reach it. Zinc baths are useful for standing out in sun-heat for this purpose; if covered by a length of muslin and stood on sharp cinders, they keep the contents insect-proof. Of course, the compost has to be turned over frequently while drying. The potting season is from August to March.
It must be noted that Lilies are potted low down in the pots; there should first be quite a quarter inch of drainage crocks, or a few large crocks with a pebble layer above them; then compost, not too fine, to fill the pots a little more than half their depth; then the bulbs go in, then the inch or half-inch covering of rather finer compost, which should all be used in a pleasantly damp condition.
The Lilies should be carried into cold frames, or unheated greenhouses, rooms, or even light sheds, and be covered over by 2 inches of coco-nut-fibre refuse, or fine cinder-ash.
Another way is to sink them in cinders out of doors, preferably on a border facing west, or north-east, backed by a wall, and heap 6 inches of sterilized fibre or leaf-mould over the tops of the pots, to lessen the amount of rain that will reach the roots. If this is done, it is essential that the cinder-bed is so deep that there are several inches of it below the pots when they are sunk. I have known gardeners simply stand pots on earth and heap cinders around and above them, which does not protect the plants at all because any insects in the ground are able to creep up the drainage holes of the pots. A north border can be made use of, if that is more convenient. When growth begins to pierce the covering material, the outdoor Lilies should be taken to a cold frame, or into the greenhouse, and sparingly watered. When the Lilies in frames, or greenhouse, have made about 6 inches of growth, they, too, will need watering with caution, after top-dressing with compost, to nearly fill the pots.
Or the Lilies can be put at once (from out of doors, or from frames, or cold glasshouse) into a temperature of 500 to 55°. Kept on a high shelf by the glass roof they will not straggle up, and a shading of soft paper - the familiar crinkled art paper in green is best of all-bid lightly over the soil and removed before waterings, will preserve the surface-roots from being sun-scorched.
It is because many Lilies spread roots visibly over the compost that top-dressings are needed, and this shading is advisable. The usual method is to topdress all at once, as described, but I prefer to do it by two operations, not bringing the compost nearly to the pots' rims until rootlets have again shown. When flowers begin, weak liquid manures can be given twice in eight days. It is excellent to give in succession liquids made with cow-manure, with horse-manure, with an ounce of soot steeped twelve hours in a muslin bag, in each two gallons of rain-water, or with one ounce of guano steeped eighteen hours in two gallons.
Lilies about to unfurl their buds can be hastened in a temperature of as much as 65°, but the more heat the more water will be needed. Full-grown plants always require plenty.
After Lilium Harrisii goes out of bloom, water must be decreased, then stopped, all but a watering by immersion often enough to prevent absolute drying up - probably this will be once a week if the pots are stood, as they should be, against a south wall in the open, with a roofing of boards or tent-canvas above them. In six or seven weeks the bulbs will have ripened, and gentle waterings will be needed to encourage them to develop in other ways.
I restart my Liliums by taking the bulbs out of compost, and plunging them in damp coco-nut-fibre refuse till they swell up plump - then repot them like the newly bought bulbs. The latter are also the better for the 'swelling' process, I believe. Any broken or decaying scales of the bulbs should be taken off, pared away by a sharp knife, and the place rubbed with clay and sand.