UNITED STATES—Olive orchards formerly inhabited some of the regions that became urban in California. A few orchard trees remained within urban gardens of the homes that encroached on them. Unfortunately, for those who did not utilize the abundant olives, these trees were horridly messy. Many decades ago, pollarding eliminated the mess without eliminating the trees.
Pollarding is extreme pruning that eliminates all, but the main trunk and a few main limbs. It deprives olive trees of their ability to bloom, by eliminating stems of a previous season that would otherwise bloom during the next season. Fruit cannot develop without bloom. For other trees that bloom only on older stems, pollarding eliminates bothersome pollen.
Pollarding has several other practical applications. It confines trees that would otherwise get too big for their respective situations. It enhances foliar color and texture for trees that display colorful foliage through summer, such as Schwedler and Princeton Gold maples. Red twig dogwood generates more colorful twigs, and more abundantly, after pollarding.
There are several justifications for this old-fashioned technique.
For agricultural purposes, pollarding generates lush vegetative growth of white mulberry to sustain silkworms, or other vegetation for livestock. It similarly generates long and thin willow stems for basketry. Various eucalypti rely on pollarding to produce juvenile foliage that is colorful and healthy enough for floral design, or aromatic enough for essential oils.
Nowadays, pollarding is unfortunately passe and even vilified. Consequently, almost no arborists learn about it. Because it is technically disfiguring and potentially unsightly, it is undesirable for many situations. Annual repetition is needed to prevent bloom or fruiting. Otherwise, restorative pruning or more extreme pollarding eventually become necessary.
For pollarding, proper technique is imperative. Such severe pruning must happen during winter dormancy. It would it be too stressful during vascular activity. Besides, bark would be very susceptible to scald if so suddenly exposed during warmer and sunnier weather. Pruning cuts must be very neat, and back to any old pollard cuts, without stubs to inhibit healing.
For millennia, olive, Olea europaea, dutifully produced oil and edible fruit for civilizations of the Mediterranean region. During the last several centuries, it migrated to do the same in other regions of similar climate throughout the World. At least two centuries ago, it got to California, and became a major agricultural commodity. Now, it lives in home gardens.
The abundant and oily fruit that justified cultivation of olive trees for thousands of years is ironically a potential nuisance for home gardens. Few people harvest and process them. Olive fruit can stain pavement and attract rodents. Fruitless or mostly fruitless cultivars of olive, and dwarf cultivars, have been increasingly popular for only the past few decades.
Olive trees are not big, but slowly develop grandly sculptural trunks. Some might be little more than 20 feet tall when mature. Few get more than 40 feet tall. Most have a few leaning trunks, which become furrowed and distended with age. The narrow and grayish evergreen leaves are about two or three inches long. Olive fruits are about an inch wide.
Horticulturist Tony Tomeo can be contacted at tonytomeo.com.