The humidity that is constantly arising by evaporation from the surface soil in hot weather is very congeniat to vegetation. To prevent its rapid exhalation is therefore a desideratum, and this is most effectually accomplished by sheltering and checking the force of sultry winds. A deficiency of moisture in the soil is frequently productive of failure in dry seasons. The only effectual means of counteracting this, is deep cultivation; and, in clayey soils, underground-draining may be considered a valuable auxiliary. Draining, combined with deep cultivation, will secure a regular and lasting supply of moisture during the dryest weather. At first sight this fact does not seem very apparent, and many are afraid to drain, under the impression that the soil would be rendered too dry. Deep cultivation, by loosening the soil, increases its capacity for moisture. Soil, like sponge, can only absorb a certain portion of water; if more falls upon it than it can retain, it becomes injurious unless carried away through drains. The increased depth of soil forms a reservoir for suspended moisture, which in dry weather is conducted to the surface by capillary attraction, where it is available for the purposes of vegetation.

Another important advantage consequent upon the removal of superfluous water from soils, is their increased temperature. Wet soil must always be cold, comparatively, because the heat of the sun is expended in evaporating moisture instead of warming the soil.

Having in a previous paper given my views respecting soil, in reference to its chemical constituents, I need not again recur to that part of the subject In the paper referred to, I urged the importance of an annual application of decaying vegetable matter on the surface to represent the periodical layer of leaves and decaying grasses in natural woods. A moments reflection will convince us of the importance of this consideration, especially as many - indeed most - evergreen shrubs are furnished with small fibry roots which run near the surface, and are consequently dependent upon this surface stratum for their ramification and growth.

The list of evergreens suitable for shrubberies is by no means so limited as might be inferred, judging from the appearance of our pleasure grounds. In order to render these remarks of some practical use, I will give a brief descriptive list of those that I have seen growing in this neighborhood, of a size sufficient to warrant their hardiness and availability for decorative purposes, when properly planted in a suitable aspect and locality.

Evergreen Shrubs #1

When I asked from the learned correspondents of the Horticulturist, over the signature of "Horticola," for information regarding shrubbery of a cheerful, evergreen habit, it was with a view of inviting more attention to a neglected topic long superseded by a continuous description of evergreen trees. It is gratifying that the subject has excited the thoughts and pens of several able writers. Mr. Munn first, and, in the April number, Mr. Saunders, have taken the field in earnest, and will, I trust, as occasion presents, give further intelligence, which will be acceptable just in proportion to its facts. The list of Mr. Saunders, for which I feel greatly indebted, though large, is by no means exhausted, but it is a very good list, and is accompanied by judicious remarks.

The only successful planting of Savin (Juniperus sabina) which I have ever seen, pleased me exceedingly. It is in the large circle before the beautifully situated mansion of Mr. Craft, a member of the bar, near Pittsburgh. Occupying the entire circle with its dense, almost black green, I exclaimed at once, here at last is a desideratum for America. It was introduced by the German settlers, and the lady of Mr. Craft, who is a most successful and enthusiastic planter, adopted it at once in laying out their grounds. I know of no more striking evergreen thus planted in this country. Once seen in a rich clump, it must become a favorite. Small plants of it from abroad, and possibly at home, by the thousand, can be had for the smallest price.*

Mr. Saunders also names the Tree Box (Buxus sempervirens). My experience with this plant indicates that when placed wholly or partially in the shade, it is perfectly beautiful, of intense green, and very much more rapid growth than is generally supposed. Fully exposed to our hot summer suns, however, it is apt to take the color of the variety called the Golden Box (Buxus aurea), which is by no means so pleasing to the eye. In England I observed that great use was made of the Tree Box, which is adapted to their moist climate; and that this had been done so many years ago, that great and pleasing results have followed. I once thought I would attempt to enumerate the Box trees that were over twelve feet high in a gentleman's pleasure-ground where I was staying, and counted a hundred and more, when my attention was called off to other beautiful objects. It is by no means uncommon to find a good cottage, of late, run up with taste near or in a copse of native trees. No better undergrowth than this, except the Hemlock, could be selected, as it is very long-lived and every year improves.

The variegated should be more sparingly introduced.

But it is not necessary solely to have reference to shrubs, or small-growing plants, where an effect is desired. And here I wish to make a suggestion to the lovers of fine planting, of the utmost interest Hemlocks, for a long period of growth, afford the best possible substitute for evergreen shrubbery; standing in the shade, too, their exquisite green shining leaves and waving branches, their young shoots so happily described by Willis - "the child-blossom and its predecessor are heightening graces, each to the other - neither so beautiful alone, and both finding room enough, and enjoying the same summer together. Parent and child are one glory." An example exists in this neighborhood, which I shall more particularly describe hereafter, with an account of the treatment of the young Hemlocks, where every kind of use has been made of this most beautiful American tree, from the magnificent single specimen, the young tree in groups and nurseries, to the unsurpassed and grateful-hued hedge. The Hemlock is most patient of the shears, and may thus be kept to any size. With submission, therefore, to the able and practical communications of your correspondents, I fearlessly pronounce the Hemlock the very best evergreen shrub we yet possess for ornamental planting.

It is, moreover, native, and free from the objections so many others are liable to - it is perfectly hardy. Disappointed planters know the full value of this important quality.

* Our common native trailing Juniper is a fine thing for this purpose.

One must read the valuable communications of practical gardeners with attention. As an instance, Mr. Saunders accidentally accounts for my frequent failures in trying the Cotoneasters, by saying "they are admirably adapted for covering rockeries, or planting on the north sides of walls." Had I known sooner that a northern aspect was essential, I might have saved some valuable lives, years back, which were sacrificed by ignorance. And herein lies the value of the Horticulturist, which is not to be read carelessly once by the learner, but should be frequently referred to. Every scrap of real knowledge in horticulture is valuable; and so numerous are the facts to be acquired, that the man who would despise a single one which might become available, is no true lover of his art Aspect, shade, sun, wind, rain, water, soil, manure, etc., every one is taken into consideration by the true horticulturist, whether he plants a tree, a Rose-bush, or a Lily. Hence the worth of experience, and hence the value of facts, communicated by those who know.

I trust the subject of evergreen shrubs will not be lost sight of by the Horticulturist, and that every one that can be enumerated will be brought out, and its habits and qualities treated of in this journal of art.