This section is from the book "The Gardener V3", 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.
I have read on page 8 of the last number of the 'Gardener' an article on "The Cultivation of Hardy Fruits," by Mr M'Millan, in which he particularly treats of the Plum. In that article the following passage occurs - "I have never tried the Plum as a pyramid, nor have I ever seen it as such. From its general appearance and habit, and the mode of pruning and training necessary, it is my opinion that, grown as pyramids, it would not succeed. I may be wrong, but my idea is, that as such it would be far more likely to make such growth as would result in the production of wood in the place of flower-buds".
I write for the purpose of narrating, not what I have myself done with the Plum as a pyramid, but what I have seen others doing; and I can draw a notable illustration of the cultivation of the Plum in this manner from what has been and is still being done with the Plum as a pyramid at the Gardens of the Royal Horticultural Society at Chiswick.
When there a few days ago, Mr A. F. Barron, the able superintendent at Chiswick, showed me a long border of pyramid Plum-trees, about two hundred in number, and comprising a full collection of the various sorts in cultivation. These trees have been planted about ten years, and average some 7 feet in height. In forming these trees into pyramids, such a number of sorts would be sure to betray marked diversities of growth; and while some could be trained to the pyramid form more readily than others, there was not a single one of the many varieties under cultivation incapable of being so trained. Some make but a spare bushy growth, others throw out clusters of fruiting-spurs that were now densely covered with blooming buds. Mr Barron is of opinion that the Plum can be cultivated in the form of a pyramid as well as any other fruit. What is mainly required is great perseverance on the part of the cultivator in the summer-pinching of the shoots, so as to insure the production of fruit as opposed to a rampant growth of mere wood.
It has been stated that Mr Rivers of Sawbridgeworth plants out pyramid Plums by the thousand, the plants being about 3 feet apart; and some good fruit-cultivators are of opinion that if pyramid Plums about 4 to 5 feet in height were planted out in rows, some 3 feet apart, and 2 feet from each other in the row, it would be an excellent method of growing Plums, and well repay the outlay incurred. Observer.