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.
A healthy well-grown Heath - no matter of what species or variety, whether in flower or out of flower - is always a pleasing object, and never fails to elicit admiration, even from those who are least susceptible of the influence of floral beauty. In all the sorts there is a symmetry and elegance in the habit and foliage peculiarly their own, while the rich yet chaste beauty of the flowers, both in form and colour, can scarcely be surpassed, rendering them worthy of all the care and application necessary to their full development. They form one of the largest groups of greenhouse plants in cultivation, an immense number of species having been introduced, from first to last, from their native habitat; and as these are being continually augmented by the labours of the hybridiser, ample scope is afforded for selection, and, if done judiciously, a show of bloom may be secured during the greater part of the year.
Notwithstanding their merits and capabilities for decoration, however, they are by no means so universally grown as they deserve, or even as they were some twenty years ago, when a few specimens were considered indispensable, even in the most limited collections, and when the Heathery was a never-failing adjunct to the large establishment. This seems now rather the exception than the rule; and where they are really grown, they too often bear the marks of careless treatment, if not utter neglect. It is no doubt quite true that in many gardens they are still grown, and brought to a perfection such as we believe they never reach in their native table-land itself; and the specimens which from time to time adorn our show-tables, reflect the highest credit upon the exhibitors. But we claim for our favourites a larger share of attention, and a far more prominent place than they at present enjoy.
In nothing does the aphorism, that "what is worth doing is worth doing well," apply with greater force than to the cultivation of Heaths. In point of fact, to obtain a good specimen both skill and attention are indispensable; not, indeed, that the difficulties are so great as to prevent any one with moderate attainments and the ordinary appliances of a greenhouse surmounting them, or that any more care is wanted than what must be taken to produce a creditable Zonale Pelargonium; but that in order to have a good specimen Heath, high culture is absolutely necessary. In speaking of a specimen, I may remark that I mean a handsome bushy plant, furnished with vigorous healthful shoots full of leaves from the pot upwards, and not the miserable starved-looking anatomies we have too often the misfortune to see, even on exhibition-tables, with naked lank branches, the top shoots attenuated and weakly, the leaves sickly and yellow, and the whole plant impaled with such a tremendous array of stakes, that the poor martyr nearly loses its identity, and the beholder is impressed with the idea that the plant is there to exhibit the symmetrical arrangement of the stakes, rather than the stakes being subservient to the requirements of the plant.
Stakes are doubtless indispensable, and in some of the varieties a goodly number is necessary; but the less they are seen the better for the plant, both as regards health and appearance.
In offering a few hints on the culture of Heaths, it is necessary to remark that, where it is at all possible, a house should be devoted to themselves, which should be span-roofed, well lighted, most efficiently ventilated, and so constructed that the plants can be kept near the glass. As in nine cases out of ten, however, such accommodation cannot be had, they should have a portion of the greenhouse allotted to them separate from the general collection, or at least among such hard-wooded plants as require similar treatment. The proper soil is pure peat, with the addition of more or less sand, according to the quality of the peat, whether naturally sandy or otherwise. The best for the purpose is obtained from hillsides or dry moors, and from spots where the wild Heath is found growing luxuriantly, and without being associated with grass or reeds, cutting the turf or sod about 4 inches deep, choosing the winter season for the purpose, as the worms are then below the top spit for protection from frost. The turfs should be chopped up with the spade and thoroughly dried before using.
As a general rule, from the beginning to the middle of May is the best season for shifting; and in this operation it should be borne in mind that the hard-wooded sorts, such as Massoni, Aristata, and Tricolor, are found naturally growing in dry situations, in a soil largely composed of the debris of coarse sandstone rocks; while the soft-wooded, such as Hyemalis, Colorans, and LinnaBoides, are for the most part found in damper situations, with less sand among the soil. In potting, therefore, the hard-wooded sorts should not only have more drainage, but a larger allowance of sand, than such as are soft-wooded and more robust in their habits.
All the kinds delight in charcoal, and small pieces incorporated with the soil and among the crocks will be found beneficial; the roots penetrate it freely, and it has the effect of absorbing any superabundance of moisture.
Thorough drainage is of the utmost importance, and from l 1/2 to 3 inches of crocks should be allowed, according to the size of the pot and the kind of plant, placing a layer of rough fibry peat over them.
In potting, the ball should not be buried deeper than to allow a very thin sprinkling of fresh soil over the surface, and the soil pressed firmly round the sides. If the soil is thoroughly dry, it can scarcely be too firm. Nothing is more fatal to Heaths than loose potting; the water is absorbed by the soft peat, the old ball gradually loses its moisture, and the plant soon becomes unhealthy. An essential condition to the successful culture of Cape Heaths is careful watering.
No plant is more impatient of either excessive drought or moisture. Over-watering soon shows its effects by the foliage getting discoloured and dropping off, the result of the soured soil gradually rotting the roots; while a thorough parching is almost always fatal; and even when the plant does survive, it is seldom that any after-treatment will compensate for the shock it sustains. The safest will be the medium, giving water copiously during the growing season, and that only when it is seen to be wanted, and gradually reducing the allowance as winter advances, at which season special care must be exercised.
Early in June they may be placed out of doors in a sheltered situation, and, where it is possible, plunged to the brims of the pots in sand or ashes, taking care that complete provision is made against worms, which are very troublesome, deranging the drainage and perforating the balls, so that it is impossible to do them proper justice in watering.
In hot summer weather, whether in the greenhouse or out of doors, they should be syringed overhead night and morning, before and after the sun. In autumn and winter, and even in long-continued wet or dull weather in summer, all the sorts are liable to mildew • and whenever the faintest symptom of this enemy is perceived, no time should be lost in applying the sulphur puff, before which it will rapidly disappear; and even though it should not be noticed, a very gentle dusting occasionally in the course of the winter will prevent, which, in this case, is emphatically better than cure. Many fine specimens are ruined by the neglect of this simple precaution; and mildew is so insidious, that very often its work is done before its presence is detected.
Immediately after the bloom is past they may be pruned or pinched, so as to keep the specimens in shape. All the sorts require this to be done regularly, and some of the soft-wooded, such as Hyemalis, are much the better of being well cut in.
In arranging the plants in the#greenhouse, each should have sufficient space to allow the light and air to penetrate all round them. Air should be admitted freely, except in very hard frost, and no more fire-heat should be given but what is absolutely necessary to keep the temperature just above the freezing-point. In point of fact, most Heaths will stand 3° or 4° of frost without apparent injury. 1 am convinced, however, that the safest course is to keep it out altogether.
I append a select list of fine varieties arranged according to their ordinary seasons of flowering: -
Grandinosa autuinnalis Princeps carnea. Vernix coccinea. Gracilis Vernalis. Hyemalis. Sindryana. Colorans.
Milanthera. Lambertiana rosea. Wilnioreana. Gracilis autumualis. Regerminans. Spencerii.
Ventricosa coccinea minor.
Ventricosa Bothwelliana alba.
Ventricosa densa carnea.
Aitonia Turnbullii. Eweriana superba. Verticillata major. Marnockiana. Ampullacea. Austiniana. Jasminiflora alba.
Cerinthoides coronata. Macnabbiana rosea. Mammosa pallida. Amabilis.
Ampullacea carnea. Jasminiflora. Retorta major.
We have received from Mr Meredith, of the Vineyard, Garston, near Liverpool, photographs of the splendid bunches of Grapes he last autumn had the honour of submitting to Her Majesty's inspection at Osborne. We may remark that Mr Meredith has invented a manure of special value for Yines, and that it is offered to the public through a Liverpool firm.