grafting

Training Trees to Fantastical Forms

Training Trees for Fantastical Forms

SHANE NEUFELD

There’s something magical about a tree that’s been carefully trained into the form of a graceful beast or an intriguing abstract shape. A trained tree or two in the yard attracts attention like no other feature. Creating formed trees involves pruning, shearing, grafting, wiring, training, staking, or combination of these. Some forms, such as those involving grafting, need to be started  while plants are young, while others—pompons, for example—may be undertaken once the plants have reached maturity. Trained forms require constant maintenance to maintain their shape. Imagination and perseverance are the only limits to the kinds of forms that can be created, though most fall into one of the following groups:

Topiary

Also called “sculptured” by some artists, topiary forms include anything you can imagine. One interesting topiary scene features a dancer and an admirer who watches her while quaffing a glass of beer. Naturally, there are simpler topiaries, too—baskets, spheres, cubes, pyramids…topiaries can be as simple or complex as the creator desires. They can often be spotted on large estates and in city parks. Yews, spruce, and broadleaf evergreens like laurels and boxwoods are particularly suited to this art form.

Bonsai

Many people associate bonsai with small shrubs, but larger plants can also be trained in the traditional Japanese manner. However, cabling or staking may be required to train parts of the tree to various heights. Any tools and equipment used to create traditional bonsai may be used to create the larger forms—the scale and plant variety is all that changes.

Espalier

Espaliers are typically two-dimensional forms, with branches trained to grow horizontally, nearly flat along a fence or wall. Pyramids and diamonds are common “pictures” drawn with espaliers, though the possibilities extend far beyond such simple shapes. The cordon, a variation of the espalier, is a form often used for fruit trees. In cordons, the branches are often trained to follow a vertical or oblique pattern.

Oriental Pompon

Oriental Pompons usually appear as upright, multi-branched forms, each branch topped with a sphere of foliage. A variation is “Hindu Pan,” which usually (but not exclusively) uses pines and is larger than the typical oriental pompon, which uses most evergreens and broadleaf evergreens.

Spirals

Spirals are relatively simple forms—a tree is trained to grow in the form of a corkscrew. Spiral forms are excellent for framing an entrance to a garden or driveway. Junipers and cedars are the most common trees used for spirals.

Serpentine

Trees trained into a serpentine form have an upright, snake-like main stem; smaller branches hang or weep down from this main stem. Birch and larch trees are the most commonly used trees for serpentines.

Dautsugi

In dautsugi, two or more different cultivars of a plant are grafted onto a single rootstock. For example, a globe spruce may be mated to a weeping Norway for a striking combination of upright and weeping branches.

Standards

Standards describe any trees that have been grafted onto a compatible understock. The height of the graft varies according to the desired effect. Top growth is usually spherical, and there are no branches along the trunk. The resulting form resembles a popsicle.

Training Shrubs to Single-Stem Tree Form

Training Shrubs to Single-Stem Tree Form

Looking to add a distinctive feature to your yard? Try training shrubs into a long, branchless central stem topped with a full head of foliage. With quality plants, the right technique and patience, you can transform your favourite shrubs into dynamic tree silhouettes. Here’s how.

  • Start with a high-quality shrub in a one or two gallon pot and plant as you would any shrub.

  • Examine the shrub and select the largest, healthiest stem. This will become the ‘trunk’ of your tree-form shrub. Prune off most of the other stems, leaving some extra branches untouched for the moment. The extra foliage of these branches will give the plant the energy it needs to grow.

  • Maintain the tree form by pruning off new side shoots so that all of the plant’s energy goes into the remaining stem.

  • Stake and rod the stem to keep it upright. The rod and stakes should remain in place until the selected stem is able to support the weight of the plant.

  • Once the shrub reaches the desired height (1.2 m of clear stem is a good guideline), clip the top to force buds out, and remove any buds on the stem. This is also the time to remove those extra branches you left on the stem for plant growth. Treat like a normal shrub to produce a nice round head.

  • The shrub will continue to produce shoots in unwanted areas. Remove these shoots to maintain the tree form.

Make sure your expectations are realistic—training will not transform a 2-m tall shrub
into a 4-m tall tree, though your shrub may grow a little taller than usual because the
plant’s energy has been redirected to a single, central stem.

You can train almost any shrub, but here are a few suggestions to get you started.

Amur maple
Russian olive
Lilac
Evans cherry
Ninebark
Potentilla
Dogwood
Hardy roses
Hydrangea
 

Multi-Stemmed Tree Forms

Many large shrubs can be trained to multi-stemmed tree forms of three, five or seven
stems. Russian olive and amur maple look beautiful when trained to these forms.

Buying Tree-Form Shrubs

If you like the look but don’t feel like doing the work, you can buy mature shrubs in tree
form. Some of these shrubs are trained to tree form (dogwood, potentilla, ninebark, hydrangea), while others are created by grafting a shrub such as lilac or caragana to a
compatible rootstock. Note, however, that grafted tree-form shrubs are generally easier
to maintain than trained tree-form shrubs, as the rootstocks are chosen both for height
and their tendency to avoid creating side shoots. Grafted tree form shrubs come in a
variety of heights. In some cases, the central stem may be a metre tall, in others only
half that. It all depends on what the grower has chosen.