This section is from the book "The Florist And Garden Miscellany". Also see: All New Square Foot Gardening: Grow More in Less Space!.
An article appeared in the Gardeners' Chronicle of the 25th November, headed, "Cultivation of Cape Heaths;" and signed, "W. P. Leach, S. Rucker's, Esq., Wandsworth, Surrey".
This communication of Mr. Leach's contains doctrines so foreign to those I advocated a few months ago in the pages of this periodical, and so opposite to the opinions of all those practical Heath growers with whom I have occasionally associated, that, in justice to myself and the readers of The Florist (particularly the amateur portion of them), I cannot permit it to pass unnoticed. I will not presume to say that Mr. Leach's system will in all cases kill; but this I will say, that so fraught is it with danger, that no nurseryman in England would adopt it.
The whole of Mr. Leach's article being too long to copy entire, I must refer the reader to the Gardeners' Chronicle of the 25th ult., selecting only the objectionable parts, which 1 shall take in the order in which they stand.
The first point upon which I am at issue with Mr. Leach is thus stated: "Many are of opinion that Heaths will not thrive intermixed with other plants; but this is a mistake. I know from experience that Heaths will thrive as well in a greenhouse, among other plants, as they would do in a heathery; in fact, some woolly-leaved kinds are the better for being kept a trifle closer than others; such are Fer-ruginea, Gemmifera major, Splendens, Massoni, Templese, and others. I have at present specimens of Ferruginea, Ampullacea, Parmenteri rosea, and others, mixed with Pelargoniums, Fuchsias, Azaleas, and other greenhouse stock, doing much better than I ever saw them do in the heathery, where air was more freely admitted. They, however, should be placed at the coolest end of the greenhouse".
This paragraph, though comparatively harmless, is nevertheless calculated to mislead the uninitiated, and create despair of ever growing successfully, or even keeping alive, this class of plants long together; when, in fact, the contrary result may be secured, if people would but content themselves with recommending natural means to obtain natural results. This genus cannot endure long together a close, humid atmosphere; it is poison to them; whilst the Pelargonium, Fuchsia, etc, luxuriate in it. How, then, can they comfortably "fraternise" together, and in the month of December too! The thing is impossible. The most robust and free-growing Heaths will exist in such a situation for a time, and even look bright and healthy; but, depend upon it, disease, in a secret form, is making daily advances, and will most assuredly terminate in death, if the plants are not timely removed. All those varieties described by Mr. Leach as being at this time vapourising in his "greenhouse stock" are some of the most difficult Heaths to manage well (except perhaps Massoni) and to keep free from mildew that I know.
To those who have only one greenhouse for general purposes, and are desirous to enjoy the delight of a well-grown, well-flowering Heath amidst their blooming plants during the summer months, I would say, Winter them in a cold frame, giving all the air possible on every fitting occasion. In very severe weather, scatter a tolerably thick layer of straw or other litter over the lights, pegging down over it a mat or thick canvass. This protection will exclude fifteen or twenty degrees of frost. The covering must of course be removed in the morning to admit light, if the cold is too severe to admit air. In this way do most of the nurserymen winter their "stock," and with perfect safety.
The next head of Mr. Leach's article treats of the soils best suited for the Erica, the proportions he uses, the season of the year most suitable for making the annual shift, and other little matters in connexion with that operation. To state all my objections to his system would lead me into a recapitulation of an article upon this subject published some time ago, and which may be found at pages 105 and 106, Vol. I., of The Florist; suffice it to say, that I disagree with him on many essential points, most especially in his recommending leaf-mould as a substitute for peat, and river for silver-sand. I cannot imagine that any grower of Heaths will ever need a substitute for peat. If he does, he will not find an efficient one in leaf-mould; therefore avoid it. As regards sand, I care but little about the colour or coarseness, but I am most particular in using it pure, thoroughly cleansing it in many waters from all impurities. For struck cuttings, and all small plants, silver-sand, with the peat, is indispensable.
I have learnt by experience that unwashed sand is most pernicious; and no wonder either, seeing what a variety of foreign matter it contains.
On the subject of "growing and summer treatment of Heaths," recommended by Mr. Leach, I must make rather liberal extracts. He says: "All the free-growing kinds of Cape Heaths succeed best out of doors, in a not overshaded place, during summer; the slow-growing sorts, as Massoni, Templese, Pulcherrima, Ferruginea, Mu-tabilis, Metulaenora, the tricolor varieties, etc. etc, are best kept in the house, or in pits; always, however, bearing in mind, that the Heath tribe requires plenty of air and little shade, except when fresh shifted..... I always give a liberal shift if the plants are well rooted, say from an 8-inch pot to a 12 or 13-inch pot, according to the variety. I prefer the West Kent pot, for, its bottom being movable, there is no occasion to break the pot in shifting, which is unavoidable when the common pot is used".
On this head of his subject, Mr. Leach is anxious to make it appear, first, that different species and varieties require somewhat different treatment to others; secondly, that sun is preferable to shade; thirdly, recommends a larger shift than is usually given; and fourthly, pots with movable bottoms are all but indispensable.
That some Heaths require treatment different to others, is an opinion by no means new; but the many years' experience I have had tells me there is no true foundation for such a belief; and the advocating such an opinion tends only to puzzle and mystify the inexperienced, creating a belief that there is more art and mystery in growing this class of plants than there really is. Some varieties will doubtless accommodate themselves to injudicious treatment better than others; but they will not thank you for it in the long run.