This section is from the book "The Gardener V1", 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.
As a pleasant, easy-to-cultivate, free-flowering, joy-giving, summer-blooming plant, give me the Pentstemon. I have a posy of them before me now, - pretty, glistening, varicoloured flowers, the produce of the side-shoots of my plants, that have unfolded their flowers despite, and apparently regardless of, the frost: they and the Chrysanthemums, with an occasional tea-scented Rose on a wall, are all I now have left me as a bequest of summer.
If Messrs Downie, Laird, & Laing had done nothing else in the way of the improvement of florists' flowers than the Pentstemon, they would have deserved well of the lovers of flowers. They took the Pentstemon in hand some years ago, and year by year they give us a batch of new varieties as beautiful as they are varied. At Edinburgh, as in London, they raise batches of seedlings; and they alone of florists in the United Kingdom have taken this flower in hand and brought it up to its present high pitch of excellence. This at least is certain, that, as far as my own knowledge can be trusted, this is the only firm that annually furnishes a batch of new flowers.
Despite its beauty, freedom of bloom, and the ease with which it is brought to a high state of perfection, it is surprising that the Pentstemon is so little grown. Amateur cultivators of gardens cannot be aware of the beauty and usefulness of this plant, or they would grow it. The Pentstemon ought to be grown; the Pentstemon deserves to be grown. I began a few years ago by obtaining a batch of plants from Messrs Downie, Laird, & Laing in the early spring, and year by year I get a few more; but as I obtain, I also discard, by weeding out varieties that I think surpassed by others that have put in appearance at a later date. But I don't destroy the discarded plants. When the time comes to do this, I turn floricultural almsgiver, and make a present of some of them to the poor cottagers that reside near me; and now many a cottage garden has an eruption of Pentstemon flowers during the summer. They are carefully tended, and treasured as sacredly as some cultivator of Orchids does a magnificent new Oncidium or a splendid Dendrobium. I don't deprive Messrs Downie & Co., or any other nurserymen, of a single order, but who shall estimate the value of the gratification the culture of these flowers affords these poor cottagers 1
"To perpetuate the named kinds," states a modern writer, "the plants must be propagated from cuttings, and it is best to resort to this practice annually, which will allow of the destruction of all the old plants as soon as the bloom is over, and sufficient cuttings have been obtained. To keep old plants through the winter entails a certain amount of trouble, for which there is no return except in the case of valuable varieties, from which it is as desirable to obtain as much stock as possible; and in this case it is best to take them up in October, put them in large pots with plenty of drainage and poor sandy soil, and house them in a cool greenhouse or airy pit. From these, cuttings may be taken at the end of September, and again from the end of February till May; so that if a thousand plants are wanted, and there is but one to begin with, it may be done in time to plant them all in the following May".
"As there are some mystical notions abroad as to the multiplication of Pentstemons, and some of the trade aver that they find a difficulty in propagating them, I will give to all mankind in one word a code for their management that cannot be misunderstood. That it may be remembered the better I shall print it in italics; and if you think it scarcely worth being so distinguished, I hope you will take my word for it that you are quite incompetent to estimate the value of the code or the necessity for its publication. "Well, here it is, twenty words in all, and they will be worth a .£20 note to many a nurseryman who has been baffled in the multiplication of Pentstemons; let amateurs set what value they please upon them. Grow them, keep them, and increase them in precisely the same manner as you grow, keep, and increase shrubby Calceolarias".
"You will observe that as the plants go out of bloom they throw up from the base a multitude of lively green shoots. Take these off, trim away the lowest leaves, and dip them into pots filled with very sandy stuff of any loamy or peaty kind, and quite poor. Place these pots in a frame or pit; shade them from strong sunshine; sprinkle frequently, but never let the soil be otherwise than very moderately moist; if nearly dry, it will be much safer than nearly wet. They will soon hold up their heads, and it will be well to expose them fully to the weather as soon as they are able to bear it, but take care not to let them be drenched with heavy rains. Keep them safe from frost all winter, and keep them also safe from damp, and for the rest you will guess how to manage. In the event of requiring large quantities, make up beds in frames, using gritty leaf-mould, loam, cocoa-nut dust, and sand in about equal proportions, and out of this mixture they will lift with fine roots next spring. Plants raised in this way may be planted out in April, and all they need is a good loamy soil and a sunny position.
It will be a strange thing if they want a single drop of water the whole season, except it may be just after being planted, if the weather happens to be dry".
The excellent and pithy instructions given in these three paragraphs are so suitable for amateur cultivators that I may be excused reproduring them. But the Pentstemon can also be raised from seed, and treated as an annual to bloom the same year. The seed should be sown in early spring, in pans, using some light fine soil, and be started into growth in a gentle bottom-heat. From the time the plants are large enough to handle till the time they are planted out to bloom, they should be pushed on as much as possible. I always give my seedling Pentstemons so raised a good bed, pretty rich, but by no means all manure, and they bloom gloriously. I seed from a few of the best named kinds, and I get good flowers, yet always purchase a few new kinds, for there is a great pleasure in proving both.
Some amateur cultivators, desirous of raising seedlings, who have little or no bottom-heat available, can sow in August, in pans, in a light sandy soil, covering the seeds but slightly, and place the pans in a cold frame; the seeds will be certain to grow. Young plants so raised can be pricked off into boxes, or planted out in a cold frame, to winter the plants; or if a good warm sheltered border can be made available, they can be planted out in the autumn, and they would be found to winter much better than old plants. At the blooming-time the plants should be staked in case of wind; and whether grouped in beds, dotted about borders, or kept in a plantation for cutting from, they are equally acceptable and useful.
To any one contemplating the provision of a collection, I would recommend the following: - Agnes Laing, Black Knight, Bridesmaid, Grandis, Henry King, Painted Lady, Snowdrop, and Stanstead Surprise. These are new varieties of Messrs Downie, Laird, & Laing, sent out in the spring of the present year, and all very fine. Of older flowers I can confidently commend Albert Tardieu, Bons Villageois, Colin Bell, Due de Lorraine, Eclat, Flower of the Day, George Sand, Grande Conde, James Rothschild, Le Lion, Maria Held, Mrs A. Sterry, Purple Perfection, Queen Victoria, Souvenir de St Paul, Sur-passe, Victor Hugo, and The Emperor. Nemo.