This section of the book is from the Guide To Hardy Fruits And Ornamentals book, by Thomas Joseph Dwyer, published in 1903.
The three species that follow below are the best of all the evergreens for Hedges. They should be planted in single rows, in trenches four feet in width and fifteen inches deep; the trees should be three feet apart and should be pruned back one-third at the time of planting.
* When to Plant
-- Evergreens can be planted in the months of April, May and June in the Spring and in August and September in the Autumn. Be sure at all times to protect the roots from the weather. Use manure about the plants the same as recommended for the deciduous hedging plants. Evergreens can be pruned to suit the individual taste, they are desirable for Hedges and we can recommend them. Further along in this work the author will have more to say about these beautiful trees.
* Thuya, Occidentialis (American Arbor Vitae)
-- One of the most desirable evergreen hedge plants, of very attractive appearance. Although a fast grower, it can be kept trimmed to any height desired.
* Picea Excelsa, (Norway Spruce).
-- A popular variety. Makes a very dense, compact hedge. Very desirable for a firm hedge to take the place of a fence.
* Picea Canadensis (Hemlock Spruce)
-- Very fine, graceful and ornamental, with fine, smooth, rich foliage, making a beautiful hedge.