This section is from the book "The Gardener V2", 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.
I know no more beautiful and fragrant hardy plant for blooming indoors or for cut flowers than this. The handsome leaves of tenderest green, and the chaste sweet flowers arching elegantly on their stalks, present a union of charms rarely beheld in one plant - a fact which the flower-loving public appear duly to appreciate. For to say nothing of the estimation in which it is held for button-hole and other bouquets, and other purposes to which it is applied in the cut state, the thousands of pots forced annually in nursery and florists' gardens about towns, to sweeten and enliven sitting-rooms, sufficiently evince the admiration bestowed upon it. A very large proportion of this supply is imported annually from Holland. The Dutch have sent us in the few bygone years sufficient to have stocked hundreds of acres to overflowing, but we are no richer in Lily of the Valley for it: imported stock is not even equal to the demand the present season, and the home-grown supply is not plentiful: nor is it so well favoured as the foreign.
And what becomes of it all, the thousands of pots of home-grown and imported together, that find ready customers in winter and spring? In private gardens, where much of it is forced, the gardener knows well the value of the old plants, and would as soon think of destroying anything else that is deemed worth keeping as of throwing them on the rubbish-heap. A year's nursing and extra good cultivation will put forced Lily of the Valley in condition for forcing again; and no doubt nurserymen and florists would be glad to get back their old plants from their customers in such a state as that there would be a reasonable chance of recovering their lost stamina. As it is, however, they never return. They become the property of the police, falling into their hands by the way of the dust-bin and the agency of Polly the housemaid. This is a poor fate for a thing of beauty that is yet capable of being made beautiful as ever; for the same care and skill that developed its charms before are able to revive them again in due time. Our present subject is one of perennial duration, and is, moreover, hardy and enduring to the utmost. It will even survive the dust-box, if quickly reclaimed while yet a little life remains; but it loves generous treatment, and well repays it.
The imported Dutch clumps and crowns give flowers superior to our home-grown ones; it is even held to be a distinct variety, differing from ours in being more robust and luxuriant. It does not, however, retain this peculiarity, but quickly degenerates when subject to the conditions of our commonplace treatment. Any superiority it shows under forcing is due, I think, rather to the better climate and soil of Holland, and the special treatment given it by the Dutch. We should not expect many or fine Strawberries in winter and spring from plants lifted to force from the quarters a week or two before putting them into heat; and though Lily of the Valley is better adapted for forcing than the Strawberry, our expectation of the best results from it by ordinary efforts is only, therefore, a little less unreasonable. Forced as it usually is about private places, in clumps lifted from an old-established bed, the pots have as many crowns in them producing leaves only as there are crowns with flowers and leaves; and the abortive ones, besides leading to overcrowding, compete from first to last with those that flower for the food the pot contains, the contest being always more or less to the detriment of the latter.
There is no reason to doubt but that, if we adopted something like the Dutch plan of preparing our plants for forcing, the results would be quite as good in every way with our own as with their plants. We would require to break up our beds in the first instance, and carefully divide and select the crowns to such an extent as our demands suggested, and to plant them, the strongest and weakest by themselves apart, in rich well-trenched ground, an inch and a-half asunder. The best time to do this is early in October, as it is also the best time for lifting and potting for forcing, but it will not yet be too late to do it when this comes to the hands of our readers, if the weather is open and mild. After planting - and in doing so the crowns ought to be almost buried - a mulching of old manure to the depth of 2 inches should be laid on the beds, and be beaten moderately firm with the spade, and blinded afterwards with a slight coating of soil. Any one having old-established beds, and unwilling to break them up for this purpose, need not do so necessarily, The crowns in such a bed may be thinned out by means of a knife carefully inserted below the one to be removed, so as to sever it from the underground stem without injuring those that are to remain.
Only the strongest in this case should be taken, and those that are left will benefit by their removal. On this plan of treating Lily of the Valley, improved plants for forcing would not be our only gain; our stock would also greatly increase, and this, to the nurseryman and florist at least, is a very important point. It may be grown at home at half the cost of the imported roots, and every one who indulges in the luxury of a pot in his room would ultimately share in the good of this economy. When lifting for forcing, or any other purpose, it is usual to discard all underground stems as useless. This is a mistake, for they may be made the means of largely increasing the stock in hand: every joint is prone to send up a crown when circumstances are favourable - that is, when there is room enough and pasturage sufficient for their development; and for the first two years it need not take up much room - a bushel of it may be put in a bed 4 feet by 6 feet. It is necessary in laying it in, to draw the soil off the bed wholly to the depth of a couple of inches, laying it on either side for handiness in putting it on again.
The stems are laid on the bed thus prepared equally and evenly, and covered up with the soil, finishing off with a mulching in the same way as with the nursing-bed for crowns, as described above.
Every one that has to supply cut flowers or plants in flower for conservatory and room embellishment in winter, knows how to force Lily of the Valley; and our remarks on its treatment, to aid beginners, may be very brief. As early as the leaves are ripe the crowns should be lifted and potted, using rich sandy loam to pot them in. Put no manure in the soil; any enriching it may want is better applied in the liquid state after the plants are well started. Pot very firm; it is scarcely possible to make the soil too firm- by pressure of the fingers merely, supposing it is in the proper state of dryness for potting. When finished, the tips of the crowns only should appear above the soil. They may then be watered, and put away in a cold frame till they are required for introducing into heat. It is always desirable to have the roots in action before the crowns begin to swell much. Mild bottom-heat, applied in a cool atmosphere, secures this. I have started Lily of the Valley and other commonly-forced hardy subjects on the top of a heap of heating leaves in the open air in winter, giving them such top protection of straw or Spruce boughs as the weather rendered necessary, and was well pleased with the results. Plants so treated come away quickly and sturdily when they are brought into heat.
Our subject will not bear rapid or hard forcing; a temperature ranging from 50° to 60° suits best in early winter, but later on it will bear a few degrees higher. Keep it moderately moist till after the leaves and flowers burst the crowns, when the supplies of water must be gradually increased, and be alternated with applications of clear mild liquid manure. The syringe, if used at all, should be discontinued some time before the leaves and flower-spikes are half-grown, especially if they are crowded in the pot; but it is preferable never to use it, taking the other ordinary means rather of keeping up atmospheric moisture instead. An over-moist atmosphere is favourable only to the production of fine flabby leaves and scanty weakly flowers that are liable to damp off on the occasion of the first check in temperature, and which under no circumstances continue to be long beautiful.