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.
In the cultivation of permanent plants - more especially of those requiring high cultivation - there is nothing of so much benefit as a change of soil. Tea-Roses - indeed all Roses - which have grown for years on the same spot, and which have been liberally treated with food in the form of top-dressings and manure-waterings, grow weakly and unhealthy in time. Tea-Roses which are annually lifted and protected, and when replanted in spring have a good quantity of wholesome loam placed next their roots, give greater satisfaction generally than those which are not so treated, but which are liberally manured instead. And common Hybrid Perpetual Roses, which stand for years in the beds and become irregular, when lifted, regulated, and replanted, do much better if some of the old soil be taken away and fresh maiden loam added in its place. Fruit-trees in heavily-manured kitchen-gardens generally do not thrive in the sense of making proper fruit-bearing wood and although lifting and root-pruning certainly induces a better habit, the difference between those replanted in the old soil and those which are treated to new loam or intelligently - made - up compost is very marked. This is all very well known, and is often enough enforced; but the facts do not seem to be acted upon as they might.
This being so, we have thought that a paper on the subject might help young beginners and amateurs whose trees may be in an unsatisfactory state, and which might be improved by a little well-directed labour. At the same time it may not be out of place to mention, that in order to succeed it is not enough to provide proper soil, and not enough to properly care for the roots of trees.
It is possible to do all that can be done and still not be successful. We have had many instances brought before us of failure and fruitlessness occurring simply because the kinds of fruit-trees, etc, were not suited to the climate. It is useless to expect success if varieties of fruit-trees are grown which will not ripen their fruit in an ordinary season, No greater blunder can be committed than hankering after the finer kinds of Plums, Pears, and even Peaches, when the crop3 of the hardier Apples, etc, are precarious from an unfavourable climate. This by the way, however, merely as a warning to beginners.
Generally speaking, fruit-trees, Roses, etc, which are greatly benefited by lifting and replanting in fresh soil, have been growing in soil that is too rich. Excessive richness has a tendency to cause an over-exuberant growth and when this occurs in a district not particularly favoured by sunshine, and where heavy rains prevail, the evil is aggravated. It is much more easy to cause unfruitfulness in fruit-trees and a scarcity of flowers on flowering-plants by manure in a cloudy climate than in a sunny one, and hence we ought to take this into our calculations. For successful fruit-tree cultivation in a cloudy wet climate, a hale loam on a dry bottom is an almost imperative necessity: a heavily - manured soil in such a climate will give great crops of wood, - while the same soil in a dry sunny climate will produce results diametrically opposite. Still, speaking generally, heavily-manured soils are to be avoided. But with wall and other trees in kitchen-gardens, it is impracticable to give the trees all the root-run that they require entirely to themselves. Vegetables should occupy the borders, and to grow these well quantities of manure have to be regularly added which very soon convert the border into a state unfavourable to fruitfulness in the trees.
It would be to little purpose to say that for all this there were no remedy. But there is a remedy, and that is lifting and replanting, at the same time giving an addition of fresh soil to the tree-roots to run in. Few people who have not seen this done are aware of the effect on the trees: they become transformed into a condition of productiveness, whereas before they were the opposite. The difficulty is to get fresh loam. To many this may be easy enough; to the majority, we are afraid, it is an impossibility. And doubtless there are many who would have no difficulty about getting the loam, who are glad to leave the trees alone for want of labour-power for it is a painful fact that many gardens are only half cultivated through want of strength. But where there is strength enough but no fresh soil, it is almost always of benefit to lift and replant over-luxuriant trees, using the best and cleanest soil at hand; for in numberless instances it is through overfeeding that barrenness is produced. It is not that the soil is exhausted, but it is because it affords too much.
In rich adhesive soils the roots of trees run out into great quill-like suckers-up of moisture and gaseous food, producing growth which the climate cannot ripen. This is more especially the case if the subsoil is wet and the roots are deep. We do not know whether it has been demonstrated or not that the temperature of the branches is affected by the heat being taken away by the cold soil; but it has been satisfactorily demonstrated that the heat of the surrounding air is appreciably lowered by the evaporation of water from the leaves. This is one reason why trees with long fleshy roots in a humid subsoil do not ripen so well as those whose roots are in a drier and warmer soil, and are, when near the surface, warmed by the sun's rays into the bargain. And another reason is, as we said, because when the latter conditions exist the growth is sooner finished, and therefore there is more time to ripen it. In addition to what has been said, it may be remarked that solidity of soil favours earliness and fruitfulness.
We once had a hand in planting a quantity of fruit-trees - chiefly Plums - all of which were planted in good turfy loam. Some of these were planted in the ordinary wall-border, and others in a border having a walk over it close up to the wall. As this walk was subjected to a good deal of traffic the soil soon became very solid. The latter although they scarcely filled their places as rapidly as the others, are now much better furnished with fruit-buds than the former, and have borne much more fruit. Roses, planted under similar conditions, have given similar results, - harder, stouter, and more floriferous growth. Were it not for the trouble consequent on breaking up the walks when trees require removal, our idea is that, with a well-made border underneath, it would give better results to run our walks close to the walls all round than to crop the borders. But the question we wish to ask, and partly to answer here, is - Do we cultivate our soils with an eye to maintaining the trees in the best condition possible 1 We think that, speaking in a general way, we do not. The one idea generally prevalent in preparing kitchen-garden ground is to keep it in the best condition possible by adding annually quantities of stable-yard manure.
Now the idea systematically carried out for a number of years ends in turning what may have been the finest brown or yellow loam into black garden-earth - rich, certainly, but pasty as putty if the soil is wet, and puddled into a most unsuitable state for fruit-trees by swarms of earthworms, to say nothing of the other insect-pests engendered by garden soil of this description. When the soil is in this state, wall-trees do not bear as they do in good loam. The cure is repeated yearly in our calendars: "Lift, root-prune, and replant into well-firmed loam." And the advice is good but the practice which converts good loam into black garden-earth is not good practice. Of late years our kitchen-garden and our hardy fruits have not had the attention that "the houses" and the parterre have had [too true. - Ed.], and consequently the improved cultivation which has brought these departments into their very high state of cultivation has absorbed too much of the attention which ought to have been given to our hardy fruits and our kitchen-garden soils. We by no means blame gardeners for this state of matters.
Fashion has led to our present demand for sensational parterres and perennial supplies of cut-flowers and decorative plants, and many gardeners have had to meet an overwhelming increase of work without any addition to their staff, and the inevitable result is neglect somewhere. But though this is true, it is also true that many do not give these matters the attention they might do and which they deserve. Our opinion is that soils are injured through getting too much farmyard straw dug into them. We have a great antipathy to soils which have lost the brown colour of their virginity, and we are certainly of opinion that with proper treatment they ought not to lose it. Were less stableyard straw dug into the soil, and its place supplied by the urine which is often wasted, this result would not so readily ensue. Practically it is an impossibility to turn brown loam into black garden-earth with urine - and practically the very finest kitchen-garden crops can be raised by its aid with very little solid manure, and the less straw the better. And many of our artificial manures might be profitably employed for the same purpose.
And the same means which are useful to prevent soil losing its best properties are of equal use in restoring what is often called worn-out soil; and if deep trenching was called into aid the results would be better still. We have sometimes seen portions of large kitchen-gardens laid down in grass, kept close by sheep, and the improvement effected was immense. We once had a hand in clearing out the whole of the beds of a large parterre, and replacing it by soil from the kitchen-garden, and the results were most favourable. What we have written is not theory merely: we have proved it to be fact, and the course laid down we are in the habit of following. Loam is not always attainable, and in cases of this kind it becomes a double reason for maintaining the soils we cultivate as near that condition as possible for although a change of soil for permanent plants is certainly as advantageous as for temporary crops, it is also as certainly true that permanent plants often - almost always - do ill because their roots are in unsuitable soil.
When the soil is right the trees themselves find a change, because the roots are ever extending outwards to "fresh fields and pastures new;" and learning the lesson thus taught, we ought, when we lift and root-prune, to fill in the pit with other soil than that removed, even although the soil may seem quite the same. No plant takes quite the same kind of food from the soil as its fellow, and although we may only make an exchange, it may be fraught with benefit to the different subjects. This may often be accomplished by lifting, trenching, and replanting, as in the case of Rose-beds, and other things similarly planted.