• From the Living Collections •

Fall 2003 - Volume 5, No. 2

Firs - Stately Conifers for the Landscape

Among Polly's efforts to broaden the range of plants cultivated on the Vineyard, she explored the diversity of evergreen trees for use as windbreaks. At that time - in the late 1950s and 1960s - pines and junipers were a common choice for this purpose, but the results were mostly ineffective and rarely attractive.

One of the several evergreen groups Polly evaluated as potential windbreaks were fir trees, handsome conifers belonging to the genus Abies. The balsam fir, Abies balsamea, and the Fraser fir, Abies fraseri, are traditionally used as Christmas trees in North America, but firs are less often used in modern landscapes. Over the past forty years, many of Polly's firs have excelled in the Arboretum, and based on their performance can be recommended for broader use. Currently, the PHA has 20 different fir taxa with key concentrations found within the conifers rows just north of the playpen and at the Arboretum center (the area between the old nursery area and the Play Pen). Firs can be used for windbreaks, but they should also be championed as exceptional specimen trees for the home landscape. The firs have proved to be so beautiful and adaptable at the PHA that we plan to expand our collection through the acquisition of more species that are grown from seed collected in the wild from their place of origin.

The roughly fifty species of the genus Abies have a wide natural distribution that includes North and Central America, Europe, North Africa, and Asia. In their native habitats, fir trees grow in mountainous zones in the subtropical and temperate latitudes of the northern hemisphere. Trees typically occur on sites that are not excessively dry and have access to moisture throughout the year.

Perhaps the most widely cultivated fir for landscape use is the white fir, Abies concolor. Occurring naturally in mountainous regions of the western Unites States, it has striking glaucous blue needles. The specific epithet, concolor, refers to the fact that both the upper and lower surfaces of the needles have a bluish cast that adds to their ornamental value. Two young trees grow at the PHA in the west field north and at the Arboretum center. The white fir creates a wonderful sight in winter, particularly when paired with the vibrant red berries of our native deciduous holly, Ilex verticillata.

Another attractive fir, also native to the western mountains of the United States, is the noble or red fir, Abies procera. In nature, magnificent mature trees grow to well over two-hundred feet tall, making it the tallest of the all the firs. Here on the Vineyard, the species grows at a slower rate and forms a tightly branched, conical silhouette. The cultivar 'Glauca' is notable for its distinct blue-gray needles and for its heavy crop of cones appearing on the uppermost branches of the tree. This selection originated in England in 1863. Our noble fir, located in conifer row three, has a gray trunk that seemingly "lights up" or "glows" in the low light of fall and winter.

A distinctive feature of many firs is the presence of two prominent white stomatal bands on the undersides of the needles. The tree in our collections that best illustrates this trait is the silver fir, Abies veitchii. Its otherwise flat, densely arranged needles curve and partially face upward, thereby exposing the white bands on the lower needle surface to create a wonderful silvery glow. Discovered by the English nurseryman, John Gould Veitch (1839-1870), in the central mountains of Japan, this remarkable tree is rarely found outside arboreta and botanical gardens. The PHA has two nice specimens in the center of the Arboretum, as well another in conifer row three.

Abies veitchii

Polly's own introduction of alpine fir, Abies lasiocarpa 'Martha's Vineyard', is a favorite of many visitors to the PHA. An exceptionally hardy taxon, this species occurs naturally in the western mountains of North America where it can grow at altitudes up to 12,000 feet in elevation. Polly grew 'Martha's Vineyard' from seed sent to her from Longwood Gardens in 1959. She was encouraged by Dr. Gustav Mehlquist of the University of Connecticut, to name and introduce the tree. Polly gave her tree the Vineyard moniker in appreciation of its adaptability to its island home, as well as its unique narrow habit and beautiful bluish needles. Abies lasiocarpa 'Martha's Vineyard' appears to be better adapted to cultivation than the species, which typically grows at higher elevations where there is less heat and humidity than here on the Vineyard.

The largest fir trees in the PHA collections are specimens of the Nordmann Fir, Abies nordmanniana. This species was discovered by Alexander Von Nordmann, a German botanist (1803-1866), and is native to the Caucasus east of the Black Sea. Our trees have prospered on our gravelly soils and have grown into magnificent specimens. The foliage, notable for its dark green color that persists throughout the winter months, has a sheen from the thick wax that covers the needles. Use of Nordmann fir as an ornamental or landscape tree has increased over the last two decades, and the plant is now more available in the nursery trade. Our impressive specimens, received in 1962, are located in the Arboretum center.

How do you tell a fir from a spruce? Well, the old adage, the needles of "Firs are Friendly, Spruces are Spiny" is a good starting point, although as with most things in life, there are exceptions. Another easy ID characteristic is the cones, which are upright on the branches in firs and pendulous on spruces. A table that details the key differences between the firs and spruces based on needle and cone comparisons is presented here.

To grow firs successfully, it is critical that the tree's need for moisture be met at the early stages of its development. Deep watering during the establishment of new transplants will help young trees develop a healthy root system and avoid the effects of drought, which include needle drying (desiccation) and stem dieback. Moisture is particularly important for trees planted in the fall that have had little time to develop new roots before the onset of cold temperatures. It is also important to provide adequate space for the trees' future growth. A tree growing in close proximity to surrounding vegetation will result in an irregular form, and the plant will likely lose its lower branches. Firs are at their best when allowed sufficient space to attain their potential as outstanding specimen trees. - T. M. Boland