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Section 16
16.1.1.
CHAPTER 1
EXOTIC CHRISTMAS TREE SPECIES
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What is an exotic Christmas tree? A simple explanation would be a tree not indigenous to the area.
Douglas fir, for example, is not an exotic to Western Canada but to Eastern Canada it is.
Scientists have found that each indigenous tree species over millions of years develops genes as a result
of evolving in a particular geographic location. The evolution of a species that is specific to the climate,
soils, and other conditions in any given location, is known as its genotype. Tree species that grow
naturally over large geographic areas contain many genotypes, and are generally ideal for research and
development for specific purpose such as Christmas tree production.
Planting exotics is a lot like prospecting. There will be many failures before you have a winner except
where scientists have already isolated the winners. All tree species grow well only within specific climatic
regions. These climatic areas have been assigned Plant Hardiness Zone Numbers. The zone numbers for
Nova Scotia range from 6b to 5a. Coastal Shelburne, Yarmouth, and Digby Counties are the warmest at
6b. The coldest is the plateau of Cape Breton at 5a. When planting exotics, select species or genotypes
of species from areas with the same or a lower plant hardiness number than the planting site. Selecting
trees from the proper plant hardiness zone is only the first step. It is no guarantee of success.
Why consider planting exotics when our industry has been and probably will continue to be based on
balsam fir? The answer is that agriculture would not be where it is today without many genetic crop
improvements. Similar gains are possible for the Christmas tree industry either through genetic
improvement of balsam, selection of exotics, or crossbreeding balsam with exotics.
Our industry will certainly soon face strong competition, both locally and in the export market. Any
grower who can shorten his crop rotation, reduce costs, and produce a better tree will be in a stronger
position.
We are far behind our American counterparts in genetic research and improvement to both indigenous
and exotic Christmas tree species. It will take many years of research to make significant genetic gains
for balsam fir so exotics may be considered in the meantime. However, if current biotechnological
research is successful, we will soon be in a catch-up situation.
Scots pine is not an indigenous species to the U.S.A. and is, therefore, an exotic. This means that 70 per
cent of the U.S. market is made up of exotic species (about 15).
The Christmas tree industry in Denmark started out before World War I with Norway spruce and later
changed to silver fir. Between World War I and World War II they grew primarily Nordmand fir. After
World War II they changed to Nobel fir, and the Christmas tree and greenery industry then expanded so
much that Nobel now accounts for 30 per cent of the country’s forestry exports.
The author made the mistake of planting two plantations with alternate rows of balsam fir and an exotic
species. In one case, the alternate exotic was Douglas fir of unknown seed source, which grew so fast
that it required two shearings per year. The Douglas fir were harvested and replanted to Scots pine,
which were harvested with the balsam.
Section 16
16.1.2.
EXOTIC CHRISTMAS TREE SPECIES
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In the second case, balsam fir was planted in alternate rows with hybrid Scots pine in 1979. The Scots
pine were imported from the U.S.A. During December 1985, 7 per cent were harvested. During December
1986, about 40 per cent more were harvested. However, several more years will be required before any
balsam will be harvested. The firs and exotics were planted alternately in rows of two, to help prevent
the possible spread of insects and diseases as well as to make removal of the exotics easier, if sold as
landscape trees. It’s worth noting that the soil of these plantations was a clay type, which is apparently
more suited to the exotics than to balsam fir.
The author has a few exotic trees saved for seed trees and grafting stock, particularly Fraser, Korean,
and Nikko firs. What do you conclude from the fact that after a consumer travels over a 30 acre lot of
balsam he singles out these exotics and offers name your price? In my opinion there is safety in diversity
in this industry. By not having all their eggs in one basket, growers are in a stronger position to survive
abnormal weather or insect and disease fluctuations. Christmas trees are becoming a status symbol, so
consumers frequently choose different species. Also, the few Douglas, Fraser, and Korean firs and Scots
pine that have been recently exported, were well received in the export market.
Much information is available on American research on various species and seed sources.
Ken Frankie, a leading nurseryman and Christmas tree grower from Marion, N.Y., has been studying
more than a dozen different Abies species (true firs). He concludes that none of his Abies exotics were
found to be superior to balsam. However, Barnmuller fir, Ernest fir, Nordman fir, as well as Fraserbalsam, and Korean-balsam crosses are certainly worth further study.
The author has not found any true exotic firs that will outperform our run-of-the-mill balsam. However,
Fraser fir or Scots pine would be recommended for frost pockets (the soil must be fertile and welldrained for Fraser). My first experience with Douglas fir was excellent, but every seed source since has
been a failure. If we can determine the proper seed source, Douglas could be a winner. Scots pine has
been a winner for me in my clay type soil, but this is not to imply that they wouldn’t have grown better
on rich, well-drained soils. I have seven seed sources presently in seedbeds and am hopeful that some
further improvement will result from these.
I also have some transplants of what appear to be wild crosses of Fraser-balsam, Korean-balsam, and
Veitch-balsam. These look quite promising, but only time will tell.
By now you must have concluded that we know very little about growing exotic species in this area for
the purpose of producing Christmas trees. There is enough encouraging data available to warrant future
research and development particularly for sites that are marginal for balsam. Early indications are that
most exotic firs are more resistant than native balsam to several insects and to broom rust. To date, I
have never observed a single broom on any of the firs of Asian origin, while native balsam in the same
plantation had a significant amount.
Section 16
16.1.3.
EXOTIC CHRISTMAS TREE SPECIES
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Additional Remarks on Exotic Species
Scots Pine (Pinus sylvestris) (Zones 2 to 9) is the most widely planted and most intensely studied of any
Christmas tree species. It grows naturally over a larger geographic area than any other pine, from Lapland
to Manchuria. As a result, it grows in many different ecological conditions and contains many genotypes.
Each genotype or seed source generally has some distinguishing characteristic such as: needle length
and colour, seed size, stem size and straightness, tree form, growth rate, temperature tolerance, disease
resistance, and so on. Northerly seed sources have very yellowish fall and winter needles and are slow
growing. Southerly sources are reported to be subject to winter damage in the Lake States. Trees from
various seed sources produce growth that contains varying years of needle retention.
Until a provenance study is made in this area, the medium growth, darker green strains from Southern
France, Spain, and the Balkans may be the best bet. The Scottish Highland source may also be a good
Scots Pine for Nova Scotia.
The Scottish Highland (Zones 2 to 9) source is reported to have medium growth, good needle
length, acceptable fall colour with good straight stems, and is quite hardy.
The Belgian and German (Zones 2 to 9) sources are very fast growing and have good needle
length but must be colour sprayed (too yellow) to be sold as Christmas trees.
The East Anglia (Zones 2 to 9) source is wildly planted but is reported to contain excessive
soft, drooping growth and low density.
The French or French Green (Zones 2 to 9) is wildly planted but many variations are
reported. Some nurseries may have misrepresented their seed sources. Some sources are
acceptable, but others have low density, short needles, crooked stems, slow growth, and poor fall
colour. These varieties are susceptible to needlecasts and brown spot.
The Spanish Variety (Zones 4 to 9) has moderate growth, blue green colour, straight stems,
good density, good fall colour, and requires minimal shearing. But it has excessive butt diameter
and is quite susceptible to several needle rusts and brown spot. Trees from this seed source are
not winter hardy in the Lake States but appear to grow well in the Annapolis Valley. This source
also grows well in heavy soils.
Scots Pine seeds from Turkey, Greece, and Yugoslavia are reported to grow much slower than
the French and Spanish sources and are susceptible to needlecasts and brown spot.
A number of hybrid or genetically improved seed sources in the U.S.A. are highly recommended but
may not grow equally well here, such as:
Section 16
16.1.4.
EXOTIC CHRISTMAS TREE SPECIES
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Pike Lake Strain, sold and developed by Noecker Pines, Michigan. This strain is reported to be
mainly from Southern France (Casadeen Masiff). The author has ordered some of these for planting
(spring 1987).
Lake Superior Blue is a strain of Scots pine sold by Armintrout’s, Michigan. This strain is reported
to be mainly of Turkish origin. The author placed several thousand of these in transplant beds
during the spring of 1986.
The Northwest Strain, sold by C. and E. Nurseries of Pennsylvania, has developed very well in
Nova Scotia, on clay type soil. This may be one of the early strains developed at the Pennsylvania
State School of Forestry in a research program commenced in the early 1950s, in cooperation with
the State’s Christmas Tree Growers Association. Research has continued and expanded by selecting
super trees, grafting, seed orchards, and controlled breeding. Selected Spanish females have been
crossed with male parents from many countries, producing Scots Pine that contain one or more
desirable characteristics.
The researchers are currently studying hundreds of progeny. Known as Penn-Tip varieties, their future
distribution will be rigidly controlled. Earlier developments are know as Penn-Sylvan. The different
families were assigned numbers, and seedlings from these studies are available from a number of American
nurseries. Future research will be directed towards developing a strain more resistant to needlecasts.
The Ontario Christmas Tree Growers Association is developing a Scots pine seed orchard of their own.
Douglas Fir (Pseudotsuga) (Zones 4 to 9) There are six species of Douglas fir four are native to
Asia and two to North America. The two North American species are P. macrocarpa and P. menziesii.
P. macrocarpa is native to Southern California and is seldom planted. P. menziesii has two
geographic varieties:
Rocky Mountain Fir, growing at altitudes of 1,900 to 11,090 feet (580–3380 m) is found from
central British Columbia to New Mexico.
Coastal Douglas Fir, grows from sea level to elevations of 7,500 feet (2290 m), and is found
from southwestern British Columbia to the Sierra Nevada Range.
Many genotypes exist throughout the natural range of these two varieties. Scientists say that even within
its native range it is risky to plant Douglas fir seedlings too far in distance or elevation from its seed
source. Much genetic improvement for Christmas tree production has been carried out in Oregon and
Washington. It seems likely that varieties exist that would grow very well in this province. All we need
is the will, the funds, and the time to identify them. The coastal strain that I tried was scrubbed due to
injury from late spring frosts.
Section 16
16.1.5.
EXOTIC CHRISTMAS TREE SPECIES
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Fraser fir (Abies fraser) (Zones 5 to 9)
Fraser fir grows naturally in North Carolina and Virginia and is sometimes called Southern balsam.
Because it flushes about two weeks later than balsam it is considered more resistant to late spring frosts
and to most damaging insects. The foliage is generally dark green with a silvery sheen on the underside.
Fraser seems more difficult to shear than balsam, and requires a good, well-drained, rich soil. Dwight
Newman, a leading grower in Maine, states that Fraser is quite susceptible to root rot if the soil is not
properly drained. He also states that Fraser fir prefers a cool site with frequent summer showers or fog,
a spring and late application of fertilizer is recommended, and spider mites are a major problem in June.
Concolor fir (Abies concolor) (Zones 5 to 9)
Concolor is an unusual fir as its needles resemble those of pine in length. They are soft, blue grey in
colour, and smell like oranges. When grafted to balsam they grow very well with no apparent problems.
However, imported seedlings all died or were destroyed when interplanted in a wild stand. A few are
growing fairly well as landscape trees. It seems they do not tolerate high acid soils. Jack Ryan of
Falmouth has a perfect 16 foot (4.8m) concolor on his lawn never sheared or touched up.
Grand fir (Abies grandis) (Zone 6)
Grand is the most fragrant fir in the world with “big fat” green needles. Ken Frankie says that it will
tolerate a wetter site than balsam, and the seed hardiness should be Zone 4 to 5. One problem is that it
loses its moisture soon after being cut. The author tried only one seed source. It winter burned badly.
Korean fir (Abies koreana) (Zone 5)
Ken Frankie states that he has observed this species growing in Vermont (Zone 3) and it reminds him of
a Fraser with more distinct whorls. I would describe it as bluish green in colour, with the underside of
the foliage being quite silvery and flashy. It appears hardy in Nova Scotia and produces cones profusely
at an early age. It is a little woodier than a balsam, but a nice tree.
Nikko fir (Abies homolepis) (Zone 4)
This Japanese fir has rather light green, very pointed needles. Ken Frankie rates this tree very low as a
Christmas tree species. However, I am quite satisfied with the few that I have grafted. Perhaps those in
my seedbed may not grow as well.
Momi fir (Abies firma)
Ken Frankie and I have had the same experience with this species. It flushes too early and is too susceptible
to spring frosts to consider further.
Section 16
16.1.6.
EXOTIC CHRISTMAS TREE SPECIES
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Veitch fir (Abies veitchi) (Zone 3)
Ken Frankie and I agree in every respect regarding this Japanese seed source. Veitch is hardy, with
beautiful green foliage, late flushing, and requires a very rich soil to maintain good colour and growth.
Its one fault is the bolting of the leaders when it reaches 4–5 feet (1.2–1.5 m) of growth. Pruning the
leaders always creates a serious dog leg problem, which is very difficult to correct. This fir also produces
cones early.
Nordman fir (Abies nordmania) (Zone 4)
This fir is of Turkish origin. Ken Frankie states that some of his trees are winter hardy in New York
State, and others are not. Nordman is slow growing, requires little shearing, its quality sells itself, and it
has very good needle retention. Ken rates this tree “near the top.” It would be a good prospect except for
its slow growth. The heavy spring frost of May 20, 1987 caused considerable damage to my 1+0 seedbed
but it also caused damage to my native balsam.
King Boriss fir (Abies borissi) (Zone 5)
Ken Frankie reports that this Balkan fir should be Zone 4, is very green, a bit slow to get started, but a
beautiful tree. He rates this tree “near the top.” Seed, however, appears to be very scarce.
Barnmuller fir (Abies barnmulleriana) (Zone 4 to 5)
Ken Frankie rates this Turkish fir “at or near the top.” It requires little or no shearing, but seeds are
difficult to acquire, and seedling establishment is slow.
Noble fir (Abies procera nobilis) (Zone 5)
This is a West Coast species with good whorls and symmetrical, bluish needles with good retention. It is
popular on the West Coast and grows well in their mild climate from 1,500 feet to 5,000 feet (460–1500
m). Kirk Forest Products Ltd. planted this species in Nova Scotia some years ago, but results are poor.
This is apparently not a species for eastern Canada.
Arizona cork bark fir (Abies lasiocarpa var. arizonica) (Zone 3 to 4)
This tree is from the mountains of Arizona and contains many genotypes ranging from dwarf to medium
growth. Ken Frankie reports having one on his front lawn that is often mistaken for a blue spruce and
can only be duplicated by grafting. I am growing four seed sources of Abies lasiocarpa. Some have
beautiful foliage, but growth has been poor to date.
Ken Frankie reports that the following three fir species winter burn in his area (New York). I have been
growing Spanish fir grafts for a number of years. They occasionally lost their terminal buds, but they are
now growing very well. Spanish has very long, dark green, sharp needles.
Section 16
16.1.7.
EXOTIC CHRISTMAS TREE SPECIES
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The Greek and Syrian sources are probably hardy in this area too.
1.
Abies cephalonica—Greek—Zone 5
2.
Abies silicia—Syria—Zone 5
3.
Abies pinsapo—Spanish—Zone 6
Ernest fir (Abies ernesti)
On March 22, 1987 Ken Frankie wrote to me about four beautiful Ernest fir that he had recently observed
on the property of Claude Heidt. Mr. Heidt (New York) has written many articles on Christmas tree
exotics and says these are the most beautiful trees he has ever grown. Ken states that this fir is of
Chinese origin and is quite rare. He is trying to import the seed from China. The needles are blunt,
ranked around the twig in bottle brush fashion, and have heavy double stripes on the underside. Tree
growth is vigorous, being better than Douglas in that area. During April, Ken supplied me with a few
scions. These were soon grafted, and are now growing very nicely. Ken is not easily excited, but he
seems to be excited over this find.
Border pine (Pinus flexilis)
Border pine is a five-needled pine, very much like our white pine except a little bluer in colour. A few
have grown fairly well on good agricultural soil but were a complete failure when interplanted in my
wild stand. For a very similar tree, stay with our native white pine.
References
Seeds of Woody Plants in the United States. Handbook No. 450. United States Dept. of Agriculture,
Washington, D.C., 30402.
Silvics of Forest Trees of the United States. Handbook No 271. United States Dept. of Agriculture,
Washington, D.C., 30402.
Notes made over many years without reference to authors mainly from articles in past issues of the
American Christmas Tree Journal, and from Christmas Trees.
Contributed by:
Leslie A. Corkum
Christmas Tree grower and Producer
P.O. Box 22, Falmouth
Nova Scotia, B0P 1L0