Gardeners' Chronicle, June 8, 1889
VEGETATION ON THE LIME SOILS OF THE MEDITERRANEAN
Henry Bennet, M.D., Torre di Grimaldi, Ventimiglia, Italy, June 1.
I BELIEVE that it is an acknowledged fact that a lime soil contains in abundance the mineral constituents required by most plants, and that with sunshine and water it may be considered a naturally fertile soil, even in the partial or total absence of manure, natural or artificial. Such is, undoubtedly, the case in the Mediterranean area, where most of the mountains and rocks — indeed, nearly all the principal geological formations — are formed by secondary limestones.
Throughout this region — the Genoese Riviera — on the islands, and on the shores of the Mediterranean, manure is very little used except in the vicinity of towns, for a very good reason: it is both rare and very expensive. Compared with the northern parts of Europe, there are very few cattle or domestic animals in the sparsely populated regions, and artificial manures may be said to be all but practically unknown. The peasantry live all but exclusively on corn or Maize flour, Beans, Chestnuts, farinaceous Dates, Olive oil, fruit and wine, consuming very little animal food, often none at all. In this all but vegetable diet they find all the elements of nutrition required both to produce heat and force, and to repair the wear and tear of the organic machinery, the body; carbon, nitrates, its mineral constituents, &c. These food habits, producing vigorous, strong, healthy organisations, prove that the theory that attributes the generation of heat and force in man wholly to nitrogenous food in the shape of animal substances is a mistake. Heat and force are principally generated from the carbon of the food, an in a railway engine; animal food does little else. but repair the wear and tear of the machinery in the body, and should not be taken in excess, as it generally is with the well-to-do.
In these southern regions, exposure to the atmosphere, and to the intense heat and light of the sun, seem to renovate the soil, to renew its vitality and fertility to a considerable extent, and to enable it (provided the supply of water be abundant) to reproduce the plants specially suited to lime soils. The requirements of such plants, however, are not very great, as evidenced by the history of the Ivy, which grows with vigour everywhere on old mortar of walls without soil; on these lime soils it is most luxuriant, and has repeatedly continued to grow with me on walls and rocks when the earth-roots had been completely severed. The large leaved African variety which I brought from Algeria, where I found it flourishing in the ravines in the sunshine, grows with marvellous vigour; in about eight years it entirely covered two sides of my old tower, 60 feet high, and I was obliged at last to destroy it, lest it should actually eat up the tower, the old mortar of which supplied it with sufficient nourishment to make it all but independent of its roots. I began by cutting it away up to the first story; but this sharp practice did not seem to make much difference, it went on living and flourishing as a parasite; so I ruthlessly, but to my very great regret, destroyed it entirely.
I do not mean to convey the idea that the value of manure is not fully recognised in the Mediterranean areas as a means of renovating exhausted soils, and of securing and increasing cereal or other crops; indeed, manure is preserved, both animal and human, as preciously as in China. Except in large towns, frequented by strangers, there are no wasteful water-closets, and all that comes from the soil is conscientiously returned to it. In that respect, with all our vaunted civilisation, we are really behind the Mediterranean and Chinese peasantry, although it must be acknowledged that their mode of dealing with this source of agricultural riches is objectionable to our fastidious tastes. The disinfection by earth as taught by Moses, and by Mr. Moule — a Chinese missionary, I believe — is still all but unknown with us, although generally practised in the Mediterranean area, in a way. The practical fact is, that I am growing a number of plants in my lime-soil on the Riviera with marvellous success without any manure at all, and that they seem to get on without it as well as the Ivy. This fact may throw some light on the traditional Mediterranean agriculture, showing, as it does, that heat, sunshine, and water do more there than they do in the north to prevent and repair soil exhaustion.
My garden consists of about 7 acres of rocks, precipices, terraces, all but overhanging the Mediterranean, fully exposed to the southern sun, and protected by high mountains from the north-east and north-west. There is very little vegetable soil of any kind, and what there is, is principally composed of the break-up of the limestone rocks, under the influence of the sun, of the spring and autumn tropical rains, and of atmospheric influences generally. Although heavy rains fall in the spring and autumn — some 25 inches, on an average, which is more than the average rainfall of Middlesex or Surrey, as it falls tropically — that is rapidly, in sheets, mostly for a few hours only at a time; and as it seldom rains at all from April until October, the climate, like that of Mexico, Australia, and the Cape, is a dry one. Water in such a locality is deficient, often absent. To remedy this deficiency, following the custom of the country, I have built for storage fourteen tanks or reservoirs. Moreover, I have bought for five hours a week, in summer, the privilege of using a permanent spring, which comes out of the rocks in a neighbouring ravine, and gives life to the village and territory of Grimaldi, in which I am located.
This spring belongs, during nine months of the year, by mediaeval prescription, to the owners of some olive mills, where the peasant proprietors have their olives crushed and the oil extracted. During the three summer months, July, August, and September, the spring is divided in hours, every week, among the landowners, and is held by them as a property. Land being valueless for sale unless water goes with it, my neighbours took advantage of my ignorance of this fact to sell me land without the water, so I have had to purchase the water separately from others. The quantity which this spring gives me every week — about 50 cubic metres or yards — in the summer, during the five hours each week, is quite insufficient for my wants; but the fact of my being a co-proprietor gives me a hold on the spring during the winter months, if not wanted for the olive-mills. I am the only one who waters after heavy rain — in order to water the rocks, as I tell my neighbours; so I manage to repeatedly deluge the place and the terraces and rocks during the winter, and to fill all my tanks, containing some 700 cubic metres, before the summer season begins. Thus, on my system of deep watering, I am radically changing and fertilising the entire property, making an oasis of it. I may add, that I have had a luminous irrigation idea. There is a high road between me and the sea, a steep ascent, which becomes a torrent-bed in heavy rains. I have obtained permission from the authorities to place a small dam on the gutter, which is on my side of the road, and carries the rain-water to the sea; as also to make a culvert under the boundary wall. By this means, when it rains heavily, I get a regular rivulet of water from the road into the lower part of the property, an abandoned quarry, which I am rapidly changing into a garden or forest of Cypresses. The lime-loving Cypresses which I have planted there, in a mere rubble of loose stones, are growing like Asparagus: Cupressus excelsa, C. elegans, C. argentea, C. Lambertiana, C. macrocarpa, C. pendula, and last, but not least, the lovely Pinus C. canadensis. I am very proud of having thus introduced "a Nile," with its cataracts, and soil-loaded water into my quarry of stone rubble. Without this irrigation it would never have grown anything but Aloes and Agaves, and now it is fast becoming a small tropical forest, bidding fair to rivalise the old quarry of Latomia at Syracuse in Sicily: parva componere magnis! I expect to grow many plants there which do not succeed on the rock soil, and to enlarge the area of Rose culture, and that without manure.
The Roses I named (May 4) as succeeding well were the Banksias, the Bengals, some Teas, such as Safrano, Madame Falcot, Gloire de Dijon, Chromatel, Maréchal Niel, Fortune's Yellow, do perfectly without manure. Indeed, I never give them any at all, and they bloom luxuriantly every year, producing flowers fit for a flower show. I have several Gloire de Dijon plants, ten or more years old, at the bottom of a half sheltered moist rock, and also of a sun-exposed wall, which are covered every year with splendid blossoms in autumn and in spring, flowering indeed, but sparsely, all winter. These are grown in the lime soil without manure, never having had an ounce since they were planted. We merely renew the old wood occasionally by pruning out old woody stems, and letting new grow, which they do to a height of 10 or 12 feet. The flowers grow on the new shoots 3, 4, or 5 feet long, like garlands, a very beautiful sight. Really the originator of the Gloire de Dijon ought to be made a baronet and have a pension for life. I believe that it is the most vigorously constitutioned Rose growing. It seems to succeed everywhere in all climates, and apparently in all weathers. I have seen it flourishing everywhere out-of-doors from the North of England to the Mediterranean.
I have, I may mention, a large bed of Safrano, Falcot, Nabonnand, and Bengals, some twelve years old; about 30 feet long by 14 broad. The plants are all old plants, which have never had a handful of manure since they were planted. The soil is merely roughly dug up and left loose twice a year, in spring after they have flowered, and in autumn after their rest from heat before the rains. They flower magnificently twice a year in autumn and in spring. Just now the bed is a mass of bloom, all but concealing the foliage. In September, after their rest, my gardener prunes them down to about two or three feet from the ground, cutting into the one, two, or three years' wood, according to size and direction. The Banksias, single and double; the Fortune, yellow; the General Lamarque, which all give in spring a perfect river of branches and bloom, never receive an ounce of manure from year's end to year's end. The latter two are scarcely pruned. Under such circumstances it would really be a waste to manure, where manure is so costly and so difficult to obtain.
I tried an experiment last autumn with a bed of three year Boubrinski, a very sweet red Tea, which flowers all winter with us, and is much esteemed. One third were left alone, the second third had their roots pruned all round, and manure added in the circular trench made for that purpose. The other third were lifted bodily, root pruned, as advised by some Rosarians, and replanted in a mixture of manure and leaf mould after eight months' growth. I find the Roses left alone, without trenching or manure, by far the most vigorous; those trenched and manured, the next best; and those taken up and replanted in rich soil the worst as regards both growth and flower. The month of May has been unusually rainy and moist, and our Roses have been flowering luxuriantly. For the last few days heat has appeared, max. 74°, min. 60°, sky hard blue, sun burning. Most of the Roses are withering. Usually the withering of the Roses from heat occurs by the 10th of May, when we feel it time to depart for pastures new.
We have an economical but very useful plan of using manure; a handful or more is placed at the bottom of the hole where the plant is to be placed, and the roots of the latter spread on it. I recollect, on one occasion, Dr. Hogg paying me a visit, and being surprised with the luxuriance of a plant in flower. He asked me to allow my gardener to dig it up, and we found the roots clinging to and all round the manure thus placed, forming, indeed, a ball with it. Thus was its luxuriance accounted for in an apparently poor soil. I recollect Dr. Hogg being also much struck with the extreme vividness of the colour of the flowers, which he attributed to the intensity of the sunlight — no doubt the true explication. Photographers say that the light is four times as intense at Nice, at midday, as it is in Paris.
Under these local conditions, the difficulty of obtaining vegetable mould and manure, and the unmitigated lime character of the soil, I am gradually limiting outdoor cultivation to lime loving plants, eliminating such as do not do well in it without any alien element. My notion of a garden is for everything to succeed, to be vigorous, healthy, happy. I have been too much saddened throughout my professional career by invalidism and bad constitutions to stand them in the garden. All that does not thrive with me is rooted up, and made away with. On another occasion I shall have something to say about some plants, such as the Linum trygynum, the Russelia juncea, &c, which must be lime plants from the marvellous way in which they flourish with me.
In conclusion, I would add that gardening on these sunny lime rocks overhanging the Mediterranean is intensely interesting. I have a small staff of local helpmates, into whom I have instilled an interest into all we do; so I and my
I can give my own experience with Iris reticulata. Some five or six years ago I planted several clumps of this one in the rock garden in a position well exposed to the west, and another in a similar position in another rock garden. One clump has multiplied exceedingly, and the other has dwindled away; until this year one plant only appeared, and that was too weak to produce its flowers. The Primulas are more fastidious in this respect than any other genus known to me.
In conclusion, I would add that gardening on these sunny rocks overhanging the Mediterranean is intensely interesting. I have a small staff of local helpmates, into whom I have instilled an interest into all we do; so I and my men, we ramble about the rocks, make tanks, build walls (no longer in mortar, but in loose stones), dig and delve round the old tower, looking for the treasures no doubt buried somewhere, hundreds of years ago, by some medieval Italian freebooting Captain Kidd, pirate by sea, robber by land, who made the tower his stronghold. We have not yet found the treasure, but, like the husbandman in Aesop's Fables, we fertilise the land. At the time of the earthquake, a great facing of rock on a mountain 1000 feet above me fell off with a great crash, tumbling into the ravine below, and revealing a cavern as large as a chapel, in the bowels of the mountain. There are many such caverns up and down in the rocks. So now we are blasting away, in likely directions, hoping to find Sinbad the Sailor's cavern, if not full of diamonds, at least of stalactites, and perhaps of Capillus veneris, our commonest Fern, should light penetrate.