Here is a terrific idea for a DIY Victorian window box flower planter from an authentic Victorian source.
A Window Flower-Box
From The Cottage Hearth, 1876
Given fresh mosses or leaves, a few trailing creepers and two or three spikes of flowers, and the effect will be charming in a window box made after any of the following descriptions. These methods are all cheap and feasible for securing the effect desired.
The box may be made of zinc, painted to suit one’s taste, or of common white pine stained and oiled, with a strip of molding or a few lichens and fir cones tacked on by way of ornament. Or prettier still, it may be turned into a rustic affair by covering it withy narrow horizontal lengths of rough-barked wood. Birch bough or laurel, or both alternating, will answer, halved lengthwise with the saw, and cut into sections to fit the box, the shelf which supports it being edged with the same. Or a gaily colored affair may be made with narrow strips of oilcloth, finished off with a wooden molding at top and bottom, a set pattern being chosen of bright solid colors, like the tiles, which are so much in vogue for more expensive arrangements. Or a most unique and tasty box may be made by first painting it white, then lay ferns, green or pressed ferns, upon the sides in tasteful designs, and sift clean brown sand over the whole side, after which remove the ferns, and the fern designs with all their delicate tracery of fronds, will appear distinctly in white.
The box we illustrate here was ornaments with a mixture of acorns and pounded shells. Cut all the acorns in half lengthwise. Cover the box with glue. Make an edge each way of acorns, and then cover the box all over with rows of acorns moderately close together. Sift the pounded shell all over the box thickly between the acorns. The acorns are varied with cone seeds and red berries cut in half.
Whatever style of box is used, unless the window seat is of unusual width, brackets must be put underneath, or a stronger pine shelf must be adjusted in the recess to support the box, and the edge which fronts the room just be ornamented or stained to match.