Topiary art is a form of structural gardening that once had great prominence in the old country. This called for the trimming and training of amenable plants in certain forms of animals, birds, or pieces of furniture.
There are today, in America, a few estates where these pieces of garden art have been formed and are grouped appropriately where they may be seen and given a measure of appreciation.
The skill required is most evident, and while some will consider them monstrosities, fine workmanship is readily admitted.
Type of Formal Gardening
Another type of formal gardening is the formation of espaliers or cordons. While this is an exhibition of gardening skills and often used as a practical means to grow special plants or to fill in limited spaces, a great field of opportunity is opened to grow ornamental trees and flowering shrubs flat against house walls, in narrow spaces, and as low borders along walks.
Astonishing results have been obtained where this has been done, and such as to attract widespread attention.
A purple-leaf European hazel planted against the wall of a building at Princeton University and pruned flat has been trained to more than the height of the third story.
Of course, the hazel does not ordinarily grow that tall. Still, the customary height of all plants is governed somewhat by the amount of surrounding space, and here, where width is prevented by pruning, vigor is spent in taller growth, and double ordinary height is reached.
Magnolia Soulangeana
Another good subject is the popular Magnolia soulangeana. This is faulty in the absence of short, spurred growth, which would fill in bare spaces along many of the main stems.
Another is the popular southern Magnolia grandiflora, beautifully set with large flowers. It has a trunk 6” inches in diameter, and the whole is 20’ feet high.
Still, another good prospect is the flowering dogwood Cornus florida, which is admirably adapted to the wall training. Innumerable other trees have been similarly grown on the various Princeton buildings.
Unique Cordon: Pear Tree
A very unique cordon could be pear trees framing a triangular plot along walks. Use good fruiting pear trees, the leading branches trained laterally as a low border all around the plot.
The height of the cordon is 18” inches, and the whole length is about 150’ feet. While fruit is hard from these plants, the chief purpose is for decorative value found in the glossy green leaves of the pear.
American Holly Espalier
One of the most remarkable features the writer has seen is an American holly, trained as an espalier against a high wall. It is 14’ feet high and 12’ feet wide.
Satisfactory training of plants like this is based upon the stringing of strong No. 12 wires, both upright and laterally, 10” or 12” inches apart.
All branches must be tied to these wires with raffia or soft twine twice around the wire. Go over the espalier once a year and replace the ties as needed.
There must likewise be regular pruning to select and guide the best growths for uprights or laterals.
It may be unnecessary to do no more than remind readers that an American holly procured for espalier work must be a fruiting plant.
There must also be a fertile-flowering plant within a short distance for pollination. Shortening growths in early summer will induce short flowering stems with happy fruiting results.
Three or Five Upright Arms
Espaliers may be formed of three or five upright arms, fan-shaped or palmetto, and in wide spreading arms of four to eight arms each.
Decide what you want for the space intended, and get plants that are already adaptable to the intended arms; that is to say, with leading branches already somewhat fan-shaped, though pruning will often present the proper spread.
Plan to have the leading growths straightaway tied that way, and let all filling-in of spaces be with short twiggy growth.
Viburnum Tomentosum Espalier
Viburnum tomentosum has been used as an espalier. It forms rigid stems and will grow high and wide.
Abelia is a beautiful wall shrub, making a marvelous floral display all Summer. But its branches are numerous and light and require much more attention than others.
Pyracantha Coccinea Lalandei
One of the finest espalier plants is Pyracantha coccinea lalandei. It readily grows 14’ feet long, is easily pruned to give density, and is most brilliant in fruit.
Forsythias are popular for walls, and F. suspense is often used because of its pendulous nature.
However, F. spectabilis has brighter foliage, and its stouter branches are more suited to training.
Some plants tend to send greater strength into the tops. Such should be started with young plants, trained, and pruned regularly to ensure an abundance of minor growths. This applies especially to wisterias and magnolias.
Right Plant For Espaliering
Do not start with espaliers unless prepared to make it a hobby. They are not to be well-started and then left to care for themselves. Once a year, at least, training and complete tying must be attended.
Then, according to the kind of plant, there are periods when the whole plant must be gone over with a knife or clippers.
The calendar is not a sufficient guide for setting pruning time. One must know the habits of the individual plant and prune to induce short, filling-in growths or flowers and fruit.
Choosing the kind of plant to grow in these forms is very important. Some are easy to train at will, while others are difficult. But a list of suitable ones cannot well be made, for there is no place to draw a definite line.
Almost any tree can be used, provided sufficient care is given and it is in the right form to start well. The latter is doubtless the most important of all.
Foundation Stems For Upright and Arms
Foundation stems for uprights and arms must be had and developed, or there will always be confusion and disorder. One good point to remember is to choose plants that tend to branch and leaf freely from the arms.
A good example is the katsura tree, Cercidiphyllum japonicum. This naturally sends out shoots from the bottom up; strangely enough, it produces leaves from wood of all ages.
A long branch, years old, will be leafy throughout. The redbud is prolific with flowers and fruit but has fewer leaves.
Water Supply and Pest Control
Adequate water supply and pest control are crucial to ensure abundant, healthy foliage.
Without good leaves, plants are shoddy and displeasing. A good commercial fertilizer should also be regularly used.
Broad-Leaved Evergreens
Broad-leaved evergreens present a rich appearance, and Liguatrum lucidum is especially recommended.
Euonymus kiautschovicus has excellent qualities but must be frequently knifed to keep it from progressing.
Magnolia virginiana, while not wholly evergreen, is one of the best if trained early and pruned to keep it well spread.
44659 by S. Mendelson Meehan