It is but a corollary of this discussion to say that plants which are simply odd or grotesque or unusual should be used with the greatest caution, for they introduce extraneous and jarring effects. They are little in sympathy with a landscape garden. An artist would not care to paint an evergreen that is sheared into some grotesque shape. It is only curious, and shows what a man with plenty of time and long pruning shears can accomplish. A weeping tree (particularly of a small-growing species) is usually seen to best advantage when it stands against a group or mass of foliage (Fig. 32), as a promontory, adding zest and spirit to the border; it then has relation with the place.
This leads me to speak of the planting of the Lombardy poplar, which may be taken as a type of the formal tree, and as an illustration of what I mean to express. Its chief merits to the average planter are the quickness of its growth and the readiness with which it multiplies by sprouts. But in the North it is likely to be a short-lived tree, it suffers from storms, and it has few really useful qualities. It may be used to some advantage in windbreaks for peach orchards and other short-lived plantations; but after a few years a screen of Lombardies begins to fail, and the habit of suckering from the root adds to its undesirable features. For shade it has little merit, and for timber none. Persons like it because it is striking, and this, in an artistic sense, is its gravest fault. It is unlike anything else in our landscape, and does not fit into our scenery well. A row of Lombardies along a roadside is like a row of exclamation points!
IV. Subtropical bedding against a building. Caladiums, cannas, abutilons, permanent rhododendrons, and other large stuff, with tuberous begonias and balsams between.
But the Lombardy can often be used to good effect as one factor in a group of trees, where its spire-like shape, towering above the surrounding foliage, may lend a spirited charm to the landscape. It combines well in such groups if it stands in visual nearness to chimneys or other tall formal objects. Then it gives a sort of architectural finish and spirit to a group; but the effect is generally lessened, if not altogether spoiled, in small places, if more than one Lombardy is in view. One or two specimens may often be used to give vigor to heavy plantations about low buildings, and the effect is generally best if they are seen beyond or at the rear of the building. Note the use that the artist has made of them in the backgrounds in Figs. 12, 13, and 43.