Espalier: how to train plants for the tracery of branches
Espalier is a way of training and pruning plants so their branches lie in an orderly and ornamental two-dimensional form. The beauty comes from the tracery of the branches. Espalier is a way to create a living border in a garden, or decorate a fence or wall.
Hang fruit on those branches and you have a plant offering superb flavor as well as beauty. The reason for that good flavor is that the espalier form allows leaves and fruits to bathe in light and air.
Espaliers have a long tradition in northern Europe, and have mostly been applied to apples and pears. Here in North America, our climates and day lengths are quite different, and so attempts at espalier here often fall short of expectations. Sure, you can bend branches in all sorts of designs, but they won't be thoroughly clothed in the requisite flowers and then fruits.
ESPALIERS THAT WORK HERE
No need to abandon espalier on this side of the Atlantic: One fruit plant that works very well as an espalier everywhere is red currant. Red currant espaliers have the additional advantage of only needing pruning two times per year. In contrast, pear or apple espaliers require monthly or more frequent pruning sessions.
A real plus for red currant espaliers is their fruits. They’re beautiful! The bright red fruits, dangling from the branches like translucent, red jewels, add much to the show.
The espalier technique I will describe can also be applied to white currants and gooseberries.
My red currant espaliers decorate the fence enclosing my vegetable garden. Each currant plant is trained to the shape of a T, with a single trunk capped by two fruiting arms that grow in opposite directions along the fence, which provides support.
HOW PLANTS TICK
Knowing a little about what makes plants tick helps in growing an espalier, and makes doing so all the more interesting.
“Apical dominance” is the tendency for the uppermost shoots on any plant to grow strongest. Plant hormones, produced in the growing tips of upright stems and at the high points of arching stems, suppress growth of shoots lower down.
By merely changing the orientation of a stem you can influence how strongly various parts of that stem grows. The plant also has a say in this, and may turn a growing stem upwards in an attempt to gain apical dominance over other stems.
Also keep in mind that horizontally oriented stems are weaker growing, more fruitful, and develop more side branches than vertically oriented stems.
Use these concepts in training and maintaining any espalier. To initially develop a strong trunk on my red currant, I chose the strongest shoot on my plant, removed all others, and then tied that retained shoot to the fence to keep it upright and vigorous.
Once this trunk-to-be grew just above the top of the 3-foot-high fence, I cut its top back to the 3-foot height, releasing the remaining buds from the suppressing effect of apical dominance. I selected two shoots that started to grow from the upper portion of the trunk to become fruiting arms, training them along the fence in opposite directions and removing all others.
To keep these developing arms growing vigorously, I left their ends free to turn upwards as I tied portions closest to the trunk to a horizontal position. As the shoots lengthened, I kept tying down the older portions.
Maintenance pruning and fruiting began even as arms were developing. The arms, because of their horizontal orientation, exhibit little apical dominance, so side branches develop freely.
Two simple cuts keep the form neat while encouraging abundant fruit production. First, just before the berries start reddening, I cut each side branch back to about 5 inches long. I perform the second cut in winter, cutting those side branches back again, this time to about an inch.
The only problem I have with my red currant espaliers, which hang onto their beautiful berries for weeks, is picking the fruits. To do so would ruin the plants' appearance, so I don’t. I have some other plants, growing as bushes, for the fruit harvest.
Lee Reich writes regularly about food for The Associated Press. He has authored a number of books, including “The Pruning Book” and “Grow Fruit Naturally.” He blogs at http://www.leereich.com/blog. He can be reached at email@example.com.