This section is from the book "The Gardener V2", 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.
Gardeners as a rule are very greedy - at least they get this name - and for my part I think I am no exception, although, in common with the most of my brother-gardeners, my greed puts nothing extra into my pocket. It often adds to my discomfiture. When large crops are taken successively, the trees in time are bound to succumb; and the employer is more than likely to forget all about the successes of the past, and think very little of them on account of the subsequent disappointment. The cause of Peaches dropping prematurely is, I believe, common to most fruits. The well-covered Pear-tree has its first, second, and third qualities of fruits on it: because it is not able to support all sufficiently, some take the lead and keep it. Apples are the same. I have seen trees with two or three dozens on them, all splendid plump fruit; while, on the other hand, I have seen them in other years having an abundant crop, with more than the half being inferior - the best not at all good specimens. In fact, there is just a certain work a fruit-tree can do, to do it right; but if we force it beyond that work, it must end in failure and disappointment.
In the case of hardy fruits, we can do without large crops every season - indeed, we do not feel it much if they should miss altogether; but not so with fruits under glass. The Peach, like the Vine, has great bearing capacities, and if well treated will repay all trouble; but "well treated" means much.
I have a small Peach-house which I have forced every year, the trees in which have not failed to produce a good crop for eight years in succession. The fruits that remained on to maturity were always excellent in quality and size. I fancy I cropped a little beyond the capabilities of the trees, and consequently some dropped off prematurely. Some of your readers will smile and say, "Thin more in future, and less will drop prematurely." This is all true, I doubt not. But I like a numerous crop, and so does my employer.
I was very much interested lately by reading in ' The Gardener' an account of an experiment with Melons - growing them almost without soil, by giving them the ingredients which form their constituent parts. I have been thinking since, if the same rule could be adopted with Peaches, it would no doubt prove very satisfactory. It is evident that any fruit-tree year after year growing in the same soil will in course of time deprive the soil wholly of whatever constituent the tree most requires. The Peach, for instance, would require an inorganic soil, on account of the many large stones it has to make. There is much written about suitable soil for different kinds of fruit-trees and plants. The secret must be, and is, that certain soils contain the elements required by certain trees and plants. So if these elements could be supplied in a consolidated form to fruit-trees, according to their wants, the result no doubt would be most satisfactory. Each season I feed my Peaches well with tank liquid-manure and guano, and no doubt this accounts for my success in having good crops each season. But as I said at first, many of the fruits I leave for a crop drop prematurely.
They are to all appearance ripe and good, being soft but sour, and about a third less than those that ripen ten or twelve days later. It is to meet this that I would suggest that food in a consolidated form might be supplied; for it is clear, when the trees can carry all the fruits through all their stages, and maintain their health and vigour, that if they got the proper assistance at the ripening point, the result would be a great success. I hope to hear from some of your scientific readers what chemical preparation I can procure to produce, not an extra large crop, but a fair one, all in perfection. Paddy in Ulster.