This section is from the book "The Gardener's Monthly And Horticulturist V26", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
I have often thought of writing a short article on pruning coniferous trees, seeing that you answer questions as how to treat old trees, and how to tie up the leaders so as to get the trees again symmetrical. Allow me to make a few remarks on these things, as you know, I have had time and opportunities to make practical observations for many years both in America and Europe.
Any one who sees our Picea Nordmanniana, Cephalonica, Cilicica and others, would suppose they had all been brought up direct with leaders; but this is not so, as Piceas among conifers are the ones which lose their leaders very often, and if they do, so much the better. You also know that if they are let go straight on they are apt to grow tall and make tap roots, consequently their transplanting is difficult and hazardous, and, what is worse, they are apt to grow thin at the sides.
Here I come in and remedy all this by pinching, with the thumb and not with the knife, while they are tender in the month of June, all other side branches that are disproportioned to the rest of the tree. For herein lies the difference, that if done in the green with the thumb no violence is done to the trees, and the sap working at once in the side branches is the result, the leaders forming their eyes for the following year. Keep this operation up for several years, then with root pruning and pinching the leaders and some unruly side branches, you will have what I call a perfect tree, which will prolong its beauty from fifteen to twenty years longer than if you had let it go at first. You will obtain a splendid specimen, broad, symmetrical and enduring. I have taken the Piceas as the most difficult section to handle.
Now Abies and Pinus are much easier. Some Pinus of course will need more or less pinching. For instance, I have had Pinus excelsa, Strobus nivea, and Austriaca, specially Pinus sylvestris, Laricio and its kindred, kept perfect by this method, good for nothing after a few years if left alone.
Abies are of all sections the easiest. Now of course the different dwarf Abies, as nigra pumila, Clanbrasiliana, Gregoriana and others, Picea pectinata compacta, and especially Picea nobilis glauca, when grafted, will remain dwarf for many years. It is one of the most beautiful objects to look upon. The use of this plant seems to have been almost entirely overlooked.
I have here some Picea lasiocarpa grafted from side branches so as to produce a peculiar form, that of a fern more than anything else. These are of course only for landscape artists, as few other persons appreciate them. Now the sum of my ideas is simply this - that a well cultivated tree or a plant of said family has no business to feel the knife, except for dead wood. That a kind that is intended for a tree can be helped to become a more perfect enduring tree by this method.
Now with weeping trees such as Abies inverta, Picca pecctinala pendula, and others, so much better again will the result be by the thumb than by the knife to develop and perfect the very form mentioned. Again, dwarf trees will be kept just so. Individuality most positive will be the result. Certainly different than if the hedge shears arc used, which make all kinds of evergreen trees alike; an abominable practice.
All other kinds, Thuyas, Biotas, Retinosporas, Taxus, in fact all will, as said above, be finer and show their respective characters in full.
Kissena Nurseries, Flushing, N. Y.